U.S. patent application number 12/376525 was filed with the patent office on 2010-08-26 for reinforced thermoplastic-resin multilayer sheet material, process for producing the same, and method of forming molded thermoplastic-resin composite material.
This patent application is currently assigned to FUKUI PREFECTURAL GOVERNMENT. Invention is credited to Kazumasa Kawabe.
Application Number | 20100215887 12/376525 |
Document ID | / |
Family ID | 40620928 |
Filed Date | 2010-08-26 |
United States Patent
Application |
20100215887 |
Kind Code |
A1 |
Kawabe; Kazumasa |
August 26, 2010 |
REINFORCED THERMOPLASTIC-RESIN MULTILAYER SHEET MATERIAL, PROCESS
FOR PRODUCING THE SAME, AND METHOD OF FORMING MOLDED
THERMOPLASTIC-RESIN COMPOSITE MATERIAL
Abstract
The present invention provides a high-quality multilayer
thermoplastic-resin-reinforced sheet material having excellent
mechanical properties and drapeability in which a thermoplastic
resin excellent in recycling efficiency and shock resistance is
used as a matrix; a method for efficiently producing the multilayer
thermoplastic-resin-reinforced sheet material in a short time; and
a thermoplastic-resin multilayer reinforced molding formed of the
multilayer thermoplastic-resin-reinforced sheet material, in which
the high quality and the mechanical properties are maintained. A
multilayer thermoplastic-resin-reinforced sheet material (11) is
formed by stacking thermoplastic-resin-reinforced sheet materials
(21A) to (21D) each formed of a reinforcing-fiber sheet material
(31), consisting of a plurality of reinforcing fibers (31f)
arranged in a predetermined direction in a sheet-like structure,
and a thermoplastic-resin sheet material (41) joined to a surface
of the reinforcing-fiber sheet material (31), and stitching them
together with an integration thermoplastic-resin fiber tow (51)
composed of the same material as the thermoplastic-resin sheet
material (41). The reinforcing-fiber sheet materials (31) are
stacked such that their reinforcing directions are multiaxial.
Inventors: |
Kawabe; Kazumasa;
(Fukui-shi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W., SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
FUKUI PREFECTURAL
GOVERNMENT
Fukui-shi, Fukui
JP
|
Family ID: |
40620928 |
Appl. No.: |
12/376525 |
Filed: |
November 21, 2007 |
PCT Filed: |
November 21, 2007 |
PCT NO: |
PCT/JP2007/072520 |
371 Date: |
February 5, 2009 |
Current U.S.
Class: |
428/56 ; 156/243;
156/301; 156/60; 156/93; 264/102; 264/300; 264/325; 428/102;
428/298.1 |
Current CPC
Class: |
B29C 43/305 20130101;
B29C 70/086 20130101; B29C 70/202 20130101; B32B 5/12 20130101;
Y10T 156/1095 20150115; B29K 2105/0854 20130101; B29C 70/504
20130101; Y10T 428/2495 20150115; Y10T 428/24033 20150115; B29K
2101/12 20130101; B29C 70/543 20130101; Y10T 428/249942 20150401;
B29C 43/20 20130101; B29C 43/30 20130101; B32B 5/26 20130101; Y10T
156/10 20150115; Y10T 428/249941 20150401; Y10T 428/24124 20150115;
B29C 43/203 20130101; Y10T 428/24851 20150115; B29C 43/36 20130101;
B29C 33/10 20130101; Y10T 442/3472 20150401; B29C 43/46 20130101;
Y10T 442/643 20150401; B29C 2043/3644 20130101; B29C 43/146
20130101; Y10T 428/187 20150115; B29C 70/24 20130101; B29C 70/465
20130101; B32B 27/12 20130101; B32B 7/08 20130101; Y10T 428/2481
20150115; Y10T 442/30 20150401 |
Class at
Publication: |
428/56 ;
428/298.1; 156/60; 156/301; 156/93; 156/243; 428/102; 264/325;
264/102; 264/300 |
International
Class: |
B32B 5/12 20060101
B32B005/12; B29C 43/02 20060101 B29C043/02; B29C 43/52 20060101
B29C043/52; B29C 70/00 20060101 B29C070/00; B32B 27/12 20060101
B32B027/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 22, 2006 |
JP |
2006-316157 |
Feb 15, 2007 |
JP |
2007-035428 |
Nov 7, 2007 |
JP |
2007-289785 |
Nov 20, 2007 |
JP |
2007-300002 |
Claims
1. A multilayer thermoplastic-resin-reinforced sheet material
formed by stacking and integrating a plurality of
thermoplastic-resin-reinforced sheet materials each formed of a
reinforcing-fiber sheet material, consisting of a plurality of
reinforcing fibers arranged in a predetermined direction, and a
thermoplastic-resin sheet material that are joined together.
2. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein, in each of the
thermoplastic-resin-reinforced sheet materials, one of the
thermoplastic-resin sheet material and the reinforcing-fiber sheet
material is joined to each surface of the other sheet material.
3. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the thermoplastic-resin-reinforced
sheet materials are each formed of a plurality of narrow
thermoplastic-resin-reinforced sheet materials arranged in a width
direction, the plurality of narrow thermoplastic-resin-reinforced
sheet materials each formed of a narrow reinforcing-fiber sheet
material, consisting of a plurality of reinforcing fibers arranged
in a predetermined direction, and a narrow thermoplastic-resin
sheet material that are joined together.
4. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the thermoplastic-resin-reinforced
sheet materials are each formed by weaving a narrow
thermoplastic-resin-reinforced sheet material formed of a narrow
reinforcing-fiber sheet material, consisting of a plurality of
reinforcing fibers arranged in a predetermined direction, and a
narrow thermoplastic-resin sheet material that are joined
together.
5. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the thermoplastic-resin-reinforced
sheet materials are stacked such that arrangement directions of the
reinforcing-fiber sheet materials are multiaxial.
6. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the cross-sectional thickness of each
reinforcing-fiber sheet material is set within ten times the
diameter of each reinforcing fiber.
7. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the plurality of stacked
thermoplastic-resin-reinforced sheet materials are stitched
together with an integration thermoplastic-resin fiber tow composed
of the same material as the thermoplastic-resin sheet
materials.
8. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by thermal adhesion of the thermoplastic-resin sheet materials.
9. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 8, wherein the plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by partial thermal adhesion of the thermoplastic-resin sheet
materials.
10. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 1, wherein the thermoplastic-resin-reinforced
sheet materials each have a bonding thermoplastic-resin material
that is melted or softened at a temperature lower than the melting
temperature of the thermoplastic-resin sheet material and deposited
on one or both surfaces of at least one of the reinforcing-fiber
sheet material and the thermoplastic-resin sheet material.
11. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 10, wherein the thermoplastic-resin-reinforced
sheet materials are each formed of the reinforcing-fiber sheet
material and the thermoplastic-resin sheet material that are bonded
together with the bonding thermoplastic-resin material.
12. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 11, the thermoplastic-resin-reinforced sheet
materials each being formed of the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material that are bonded together
with the bonding thermoplastic-resin material, the bonding
thermoplastic-resin material being deposited on one or both
surfaces of each thermoplastic-resin-reinforced sheet material,
wherein the amount of deposition per unit area of the bonding
thermoplastic-resin material for bonding the reinforcing-fiber
sheet material and the thermoplastic-resin sheet material is
different from the amount of deposition per unit area of the
bonding thermoplastic-resin material deposited on one or both
surfaces of each thermoplastic-resin-reinforced sheet material.
13. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 11, the thermoplastic-resin-reinforced sheet
materials each being formed of the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material that are bonded together
with the bonding thermoplastic-resin material, the bonding
thermoplastic-resin material being deposited on one or both
surfaces of each thermoplastic-resin-reinforced sheet material,
wherein the bonding thermoplastic-resin material for bonding the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material is a resin different from the bonding thermoplastic-resin
material deposited on one or both surfaces of each
thermoplastic-resin-reinforced sheet material.
14. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 10, wherein the amount of deposition per unit
area of the bonding thermoplastic-resin material is within 3% of
the weight per unit area of the reinforcing-fiber sheet
material.
15. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 10, wherein the plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by heat-melting or heat-softening the bonding thermoplastic-resin
material.
16. The multilayer thermoplastic-resin-reinforced sheet material
according to claim 15, wherein the plurality of stacked
thermoplastic-resin-reinforced sheet materials are partially bonded
together by partially heat-melting or heat-softening the bonding
thermoplastic-resin material.
17. A method for producing a multilayer
thermoplastic-resin-reinforced sheet material, the method
comprising: a sheet forming step for forming a
thermoplastic-resin-reinforced sheet material by joining a
reinforcing-fiber sheet material, consisting of a plurality of
reinforcing fibers arranged in a predetermined direction, and a
thermoplastic-resin sheet material, a stacking step for stacking a
plurality of the thermoplastic-resin-reinforced sheet materials in
a thickness direction, and an integration step for integrating the
plurality of stacked thermoplastic-resin-reinforced sheet
materials.
18. The method for producing the multilayer
thermoplastic-resin-reinforced sheet material according to claim
17, wherein, in the sheet forming step, one of the
thermoplastic-resin sheet material and the reinforcing-fiber sheet
material is joined to each surface of the other sheet material.
19. The production method according to claim 17, wherein, in the
sheet forming step, a narrow thermoplastic-resin-reinforced sheet
material is formed by joining a narrow reinforcing-fiber sheet
material, consisting of a plurality of reinforcing fibers arranged
in a predetermined direction, and a narrow thermoplastic-resin
sheet material, and a plurality of the narrow
thermoplastic-resin-reinforced sheet materials are arranged in a
width direction to form the thermoplastic-resin-reinforced sheet
material.
20. The production method according to claim 17, wherein, in the
sheet forming step, a narrow thermoplastic-resin-reinforced sheet
material is formed by joining a narrow reinforcing-fiber sheet
material, consisting of a plurality of reinforcing fibers arranged
in a predetermined direction, and a narrow thermoplastic-resin
sheet material, the narrow thermoplastic-resin-reinforced sheet
material is woven into the thermoplastic-resin-reinforced sheet
material.
21. The production method according to claim 19, wherein, in the
method for forming the narrow thermoplastic-resin-reinforced sheet
material in the sheet forming step, after the
thermoplastic-resin-reinforced sheet material is formed by joining
the reinforcing-fiber sheet material, consisting of the plurality
of reinforcing fibers arranged in a predetermined direction, and
the thermoplastic-resin sheet material, the
thermoplastic-resin-reinforced sheet material is cut in a length
direction, at a desired interval in a width direction, to form the
plurality of narrow thermoplastic-resin-reinforced sheet
materials.
22. The production method according to claim 17, wherein, in the
stacking step, a plurality of the thermoplastic-resin-reinforced
sheet materials are stacked such that the arrangement directions of
the reinforcing fibers are multiaxial.
23. The production method according to claim 17, wherein, in the
sheet forming step, the reinforcing-fiber sheet material is formed
into a sheet-like structure in which a plurality of reinforcing
fibers are arranged in a predetermined direction, the
cross-sectional thickness of the reinforcing-fiber sheet material
being set within ten times the diameter of each reinforcing
fiber.
24. The production method according to claim 17, wherein, in the
sheet forming step, the reinforcing-fiber sheet material is formed
from a wide and thin multi-filament spread thread formed by
continuously spreading, in a width direction, a reinforcing fiber
tow consisting of a plurality of filament-type reinforcing fibers
bundled together.
25. The production method according to claim 17, wherein the sheet
forming step includes a deposition step for depositing a bonding
thermoplastic-resin material that is melted or softened at a
temperature lower than the melting temperature of the
thermoplastic-resin sheet material on one or both surfaces of the
thermoplastic-resin-reinforced sheet material or the narrow
thermoplastic-resin-reinforced sheet material.
26. The production method according to claim 17, wherein the sheet
forming step includes a deposition step for depositing a bonding
thermoplastic-resin material that is melted or softened at a
temperature lower than the melting temperature of the
thermoplastic-resin sheet material to one or both surfaces of at
least one of the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material, and a joining step for joining
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material by disposing one of the reinforcing-fiber sheet
material and the thermoplastic-resin sheet material on one or both
surfaces of the other sheet material with the bonding
thermoplastic-resin material therebetween and by subjecting them to
heat or heat and pressure at a temperature lower than the melting
temperature of the thermoplastic-resin sheet material to melt or
soften the bonding thermoplastic-resin material.
27. The production method according to claim 17, wherein, in the
integration step, the plurality of stacked
thermoplastic-resin-reinforced sheet materials are stitched
together with an integration thermoplastic-resin fiber tow composed
of the same material as the thermoplastic-resin sheet
materials.
28. The production method according to claim 17, wherein, in the
integration step, the plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by applying heat or heat and pressure to the plurality of stacked
thermoplastic-resin-reinforced sheet materials to allow the
thermoplastic-resin sheet materials in the respective layers to be
thermally adhered to the reinforcing-fiber sheet materials in upper
and lower layers in a thickness direction.
29. The production method according to claim 26, wherein, in the
integration step, heat or heat and pressure is partially applied to
the plurality of stacked thermoplastic-resin-reinforced sheet
materials to allow the thermoplastic-resin sheet materials in the
respective layers to be thermally adhered to the reinforcing-fiber
sheet materials in upper and lower layers in a thickness
direction.
30. The production method according to claim 25, wherein, in the
integration step, heat or heat and pressure is applied to the
plurality of stacked thermoplastic-resin-reinforced sheet materials
at a temperature at which the bonding thermoplastic-resin material
is melted or softened so as to bond the layers of the plurality of
stacked thermoplastic-resin-reinforced sheet materials with the
bonding thermoplastic-resin material.
31. The production method according to claim 30, wherein, in the
integration step, heat or heat and pressure is partially applied to
the plurality of stacked thermoplastic-resin-reinforced sheet
materials at a temperature at which the bonding thermoplastic-resin
material is melted or softened so as to partially bond the layers
of the plurality of stacked thermoplastic-resin-reinforced sheet
materials with the bonding thermoplastic-resin material.
32. A thermoplastic-resin multilayer reinforced molding obtained by
cutting a multilayer thermoplastic-resin-reinforced sheet material
produced by the production method according to claim 17 into pieces
having a desired size, stacking a desired number of the pieces in a
shaping mold at a desired angle, and performing hot press molding
to allow the reinforcing-fiber sheet material to be impregnated
with the thermoplastic-resin sheet material, and, in the case of
stitch-integration, with the integration thermoplastic-resin fiber
tow.
33. A thermoplastic-resin multilayer reinforced molding obtained by
cutting a multilayer thermoplastic-resin-reinforced sheet material
produced by the production method according to claim 17 into pieces
having a desired size, stacking a desired number of the pieces in a
preforming mold at a desired angle, performing hot press molding to
allow the reinforcing-fiber sheet material to be impregnated with
the thermoplastic-resin sheet material, and, in the case of
stitch-integration, with the integration thermoplastic-resin fiber
tow, to obtain a preformed laminate, heating the preformed laminate
to make it deformable, placing it in a shaping mold, and performing
press molding.
34. A method for forming a thermoplastic-resin composite-material
molding from a molding material composed of a reinforcing fiber
material and a thermoplastic resin material, the method comprising:
disposing the molding material between a pair of shaping molds
formed to have a uniform thickness at contact portions with respect
to the molding material; clamping the molding material between the
shaping molds in a manner that inside gas can be discharged from
the periphery of the molding material; placing the shaping molds
clamping the molding material therebetween between a pair of hot
press molds having contact surfaces formed to fit contact surfaces
of the shaping molds; performing hot pressing; placing the shaping
molds having gone through the hot pressing between a pair of cold
press molds having contact surfaces formed to fit the contact
surfaces of the shaping molds; and performing cold pressing to cure
the thermoplastic resin material melted and impregnated into the
layers.
35. The forming method according to claim 34, wherein the molding
material is clamped such that a space into which gas inside the
molding material is discharged is formed between the shaping molds,
and the space into which the gas is discharged is brought into a
vacuum or reduced pressure state.
36. The forming method according to claim 34, wherein a plurality
of the shaping molds clamping the molding material are stacked and
subjected to hot pressing and cold pressing.
37. The forming method according to claim 34, wherein hot pressing
is sequentially performed using a plurality of hot press molds
having different temperatures.
38. The forming method according to claim 34, wherein cold pressing
is sequentially performed using a plurality of cold press molds
having different temperatures.
39. The forming method according to claim 34, wherein the contact
portions of the shaping molds are formed to be thin.
40. The forming method according to claim 34, wherein the shaping
molds are composed of a carbon fiber carbon composite material.
41. The forming method according to claim 34, wherein the contact
surfaces of the shaping molds to be in contact with the molding
material are treated with a release treatment.
42. The forming method according to claim 34, wherein, in the
molding material, the thermoplastic resin material serving as a
matrix is unevenly distributed between layers of the reinforcing
fiber materials.
Description
TECHNICAL FIELD
[0001] The present invention relates to a sheet material suitable
for producing a three-dimensional thermoplastic-resin
composite-material molding and a method for forming the same. More
specifically, the present invention relates to a multilayer
thermoplastic-resin-reinforced sheet material formed by stacking
and integrating a plurality of thermoplastic-resin-reinforced sheet
materials each formed by joining a thermoplastic-resin sheet
material to a reinforcing-fiber sheet material consisting of
reinforcing fibers, such as carbon fibers, arranged in a sheet-like
structure; a method for producing the same; and a method for
forming a thermoplastic-resin composite-material molding from a
molding material composed of the reinforcing fiber material and the
thermoplastic resin material.
BACKGROUND ART
[0002] Fiber-reinforced composite materials composed of a fiber
material and a matrix material are light and stiff materials, and
enable various functional designs. Such fiber-reinforced composite
materials are used in a wide range of fields, including aerospace
field, transportation field, structural engineering field, and
exercise equipment field. Currently, fiber-reinforced plastics
(FRPs) composed of a reinforcing fiber material, such as carbon
fibers or glass fibers, and a thermosetting resin material are the
mainstream. However, it is thought that the development of moldings
using a thermoplastic resin material as a matrix resin will
increase in the future because of their advantages such as
improvements in recycling efficiency, short-time moldability, and
shock resistance of the moldings.
[0003] Meanwhile, in forming moldings, to ease forming and reduce
the forming cost, moldings formed of a multiaxially reinforced
sheet material, in which reinforcing fiber materials are stacked
such that their reinforcing directions are multiaxial, and a method
for forming the same are attracting attention.
[0004] Thus, it is expected to produce a sheet material composed of
a multiaxially reinforced sheet material, in which reinforcing
fiber materials are multiaxially laminated, and a thermoplastic
resin material, and a high-quality, low-cost molding composed of
such a sheet material, which can be produced in a short-time.
[0005] As an example of the sheet material composed of a
reinforcing fiber material and a thermoplastic resin material,
Patent Document 1 discloses that a prepreg sheet or a semi-prepreg
sheet containing a thermoplastic resin is formed by stacking a
reinforcing fiber sheet formed of a plurality of reinforcing fiber
tows arranged in one direction and a thermoplastic-resin nonwoven
fabric made of thermoplastic resin fibers formed into nonwoven
fabric, and applying pressure while applying heat to melt the
thermoplastic-resin nonwoven fabric so that the reinforcing fiber
tows are impregnated or half-impregnated with the thermoplastic
resin.
[0006] As an example of the sheet material composed of a
reinforcing fiber material that is multiaxially reinforced and a
thermoplastic resin material, Patent Document 2 discloses a
reinforcing multiaxial stitched fabric formed by stacking at least
two layers, each formed of multiple reinforcing fiber filaments
arranged parallel to one another in a sheet-like structure, in a
crosswise manner to form a laminate, and stitching the laminate
with a low-melting polymer thread. Also disclosed is that, by
impregnating the reinforcing multiaxial stitched fabric with a
thermosetting resin or a thermoplastic resin and subjecting it to
heat molding at the melting point of the low-melting polymer thread
or higher, an FRP molding having excellent surface smoothness with
no organization of the stitching thread is obtained.
[0007] Patent Document 3 discloses a fiber-reinforced sheet
reinforced in three directions and a method for producing the same,
in which a prepreg sheet impregnated with a thermoplastic resin is
arranged in a longitudinal direction and another
thermoplastic-resin prepreg sheet is spirally wrapped around this
thermoplastic-resin prepreg sheet. Also disclosed is a
fiber-reinforced sheet reinforced in four directions formed by
disposing a thermoplastic-resin prepreg sheet on the
three-directionally reinforced fiber-reinforced sheet at 90.degree.
with respect to the longitudinal direction thereof.
[0008] Patent Document 4 discloses a method and apparatus for
producing a multiaxially fiber-reinforced composite sheet, in which
a cohesive unidirectional lap is formed from a combined filament
yarn consisting of a reinforcing filament and an organic material
filament, the lap is folded laterally with respect to the traveling
direction and subjected to heat or heat and pressure to fix the
reinforcing threads/organic material. Also disclosed is that the
organic material is a thermoplastic resin serving as a base
material, and the composite sheet is provided to enable production
of complex-shaped composite-material moldings.
[0009] Patent Document 5 discloses a multiaxially laminated
reinforcing fiber sheet and a method for producing the same, in
which reinforcing fiber tows are spread and widened such that the
width of 1000 threads is 1.3 mm or more and formed into a
reinforcing fiber sheet, the reinforcing fiber sheet is then formed
into oblique reinforcing fiber sheets whose reinforcing directions
are oblique, and then the oblique reinforcing fiber sheets are
stacked and bonded together with a heat adhesive or stitched
together with a thread or a fiber having a reinforcing effect. Also
disclosed is a method in which, when the oblique reinforcing fiber
sheets are stacked, a matrix layer composed of a thermoplastic
resin is disposed between the layers.
[0010] Patent Document 6 discloses a method for forming a
fiber-reinforced thermoplastic composite material, in which a
multiaxially laminated sheet is produced by integrally stitching
multiaxially laminated prepreg tapes composed of reinforcing fibers
impregnated with a thermoplastic resin, and the multiaxially
laminated sheet is cut or laminated. Also disclosed is that,
because the reinforcing fibers are preliminarily impregnated with
the thermoplastic resin, forming can be performed in a relatively
short time and the forming cycle can be reduced.
[0011] As a method for forming a molding using a thermoplastic
resin material as a matrix resin, for example, Patent Document 7
discloses a method in which a material is disposed between a flat
plate and a patterned plate and inserted into a hot press to melt
the thermoplastic resin, the material, disposed between the plates,
is taken out and then inserted into a cold press to be subjected to
cooling, and the molding is taken out. Patent Document 8 discloses
a method for producing a fiber-reinforced thermoplastic composite
molding in which a fiber-reinforced thermoplastic composite
material is placed in a female open mold, the entire open mold is
covered with a heat-resistant bag, the air between the bag and the
open mold is evacuated, and then hot pressing is performed.
[0012] Patent Document 1: Japanese Unexamined Patent Application
Publication No. 2003-165851
[0013] Patent Document 2: Japanese Unexamined Patent Application
Publication No. 2002-227066
[0014] Patent Document 3: Japanese Unexamined Patent Application
Publication No. 2006-224543
[0015] Patent Document 4: Japanese Unexamined Patent Application
Publication (Translation of PCT Application) No. 2004-530053
[0016] Patent Document 5: Japanese Unexamined Patent Application
Publication No. 2006-130698
[0017] Patent Document 6: Japanese Unexamined Patent Application
Publication No. 2007-1089
[0018] Patent Document 7: Japanese Unexamined Patent Application
Publication No. Hei 6-320655
[0019] Patent Document 8: Japanese Unexamined Patent Application
Publication No. 2004-276471
[0020] Patent Document 9: Pamphlet of International Publication No.
2005/002819
[0021] Patent Document 10: Japanese Unexamined Patent Application
Publication No. 2005-029912
[0022] Non-Patent Document 1: Kazumasa Kawabe et al. "Simulation of
Thermoplastic Resin Impregnation for Developing Thermoplastic Resin
Prepreg Apparatus", Industrial Technology Center of Fukui
Prefecture, Heisei 12 Research Report No. 17
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0023] In the above-described Patent Document 1, using a
thermoplastic resin in the form of nonwoven fabric, a prepreg sheet
or a semi-prepreg sheet formed of fiber tows impregnated or
half-impregnated with the thermoplastic resin is obtained. As a
result of the thermoplastic resin being melted and impregnated or
half-impregnated into the fiber tows, the drapeability of the
prepreg sheet is degraded even if it is thin. Thus, it is difficult
to fit the prepreg sheet into a three-dimensional metal mold.
Furthermore, when the prepreg sheet or the semi-prepreg sheet is
produced, application of heat and pressure to the extent that the
thermoplastic-resin nonwoven fabric is melted and impregnated into
the fiber tows is needed. This raises problems in that the molding
apparatus becomes large and the molding speed cannot be
reduced.
[0024] In Patent Document 2, a reinforcing multiaxial stitched
fabric is impregnated with a resin to produce an FRP molding. When
a thermosetting resin having good flowability is to be impregnated,
the resin can be easily impregnated into fibers of the reinforcing
fiber filaments constituting the reinforcing multiaxial stitched
fabric. However, when a thermoplastic resin that is viscous in a
melted state and has poor flowability is to be impregnated,
impregnation of the resin into the fibers of the reinforcing fiber
filaments is very difficult. Therefore, a thermoplastic-resin
composite-material molding formed of such a reinforcing multiaxial
stitched fabric has problems in that the time for resin
impregnation to obtain a molding is long, which increases the
molding cost, and in that many portions not impregnated with the
resin, i.e., voids (gaps), are formed, which degrades the
mechanical properties.
[0025] In Patent Documents 3 and 6, a multiaxially reinforced sheet
is produced from a prepreg sheet and a prepreg tape impregnated
with a thermoplastic resin. There is a problem, however, in that,
because the prepreg sheet and the prepreg tape composed of
reinforcing fiber tows impregnated with a thermoplastic resin
material are stiff, a sheet formed of such sheets or tapes that are
multiaxially oriented has poor drapeability and is difficult to be
fitted to a three-dimensional metal mold. In addition, in order to
produce the thermoplastic-resin prepreg sheet and tape, a
prepreg-sheet producing process, in which reinforcing fiber tows
are impregnated with a thermoplastic resin, is required. However,
because impregnation of a thermoplastic resin into reinforcing
fiber tows is not easy and requires production time, this results
in a problem in that the production cost of FRP moldings
increases.
[0026] In Patent Document 4, a combined filament yarn composed of a
reinforcing filament and an organic material filament is used.
However, it is difficult to uniformly combine the reinforcing
filament and the organic material filament. Thus, it is highly
possible that the resulting composite-material molding exhibits
non-uniform distribution of fibers has voids. Furthermore, because
the combined filament yarn is produced one by one, the production
cost of the combined filament yarn is high. This leads to a problem
in that the cost of the resulting composite-material molding
increases.
[0027] In Patent Document 5, a plurality of spread and widened
reinforcing fiber tows are bonded together into a reinforcing fiber
sheet with a thread having an adhesive function, an adhesive fiber
web, or a porous adhesive layer. Because the plurality of spread
and widened reinforcing fiber tows are bonded together with only
the thread having an adhesive function, the adhesive fiber web, or
the porous adhesive layer, a certain amount of the thread or
adhesive is necessary. If the amount of the thread having an
adhesive function, adhesive fiber web, or porous adhesive layer to
be used is insufficient, it is difficult to bond the plurality of
reinforcing fiber tows. Even if bonding was possible, because the
reinforcing fiber tows are easily unraveled and the spread and
widened reinforcing fiber tows are bundled, the shape of a
reinforcing fiber sheet cannot be maintained.
[0028] In the example, a uniaxial reinforcing fiber sheet is formed
in which carbon fiber tows spread and widened to a width of 31 mm
are arranged and bonded together with a fiber web having a weight
of 4 g/m2 made of hot-melt adhesive fibers. Because the amount of
the carbon fibers used is about 24.5 g/m2, the amount of the
hot-melt adhesive used is about 16.3% of the amount of the carbon
fibers used.
[0029] In Patent Document 5, after an oblique reinforcing fiber
sheet is produced from a reinforcing fiber sheet, the oblique
reinforcing fiber sheet and a thermoplastic resin matrix layer are
stacked and bonded together with a heat adhesive or stitched
together with a thread or a fiber having a reinforcing effect.
Thus, a multiaxially laminated reinforcing fiber sheet for
producing a thermoplastic-resin composite-material molding is
produced. Because a certain amount of the thread having an adhesive
function, adhesive fiber web, or porous adhesive layer is used to
make the reinforcing fiber sheet, such an adhesive is combined with
the thermoplastic resin serving as the matrix. This may degrade the
mechanical properties of the composite-material molding. In
addition, stitching with the thread or the fiber having a
reinforcing effect may destroy the straightness of the reinforcing
fibers because, when a multiaxially laminated reinforcing fiber
sheet is subjected to hot press molding to produce a
composite-material molding, the thickness provided by the stacked
oblique reinforcing fiber sheet and thermoplastic resin matrix
layer decreases as a result of the impregnation of the
thermoplastic resin into the reinforcing fiber tows, which slackens
the thread or the fiber having a reinforcing effect. Such a slack
thread or fiber does not reinforce the composite-material molding
in the thickness direction, but rather exists as a foreign matter
and causes degradation of the mechanical properties of the
composite-material molding.
[0030] As a result of intensive research and development, the
present inventor confirmed that, as disclosed in Non-Patent
Document 1, as the thickness of fiber tows decreases, a viscous
thermoplastic resin can be impregnated into fiber tows in a shorter
time, and developed, as disclosed in Patent Document 9, a
tow-spreading method for producing a wide and thin multi-filament
spread sheet from a large-fineness fiber tow, which is low in
material cost. Furthermore, as disclosed in Patent Document 10, a
method and apparatus for producing a thermoplastic-resin prepreg
sheet from a sheet composed of a plurality of multi-filament spread
threads arranged in a width direction without leaving gaps and a
thermoplastic resin sheet is developed.
[0031] On the basis of the above-described findings and
tow-spreading method, the present invention intends to provide a
thermoplastic-resin-reinforced sheet material using a thermoplastic
resin, which is excellent in recycling efficiency and shock
resistance, as a matrix and having excellent straightness and
distribution of fibers and excellent moldability into a molding; a
high-quality multilayer thermoplastic-resin-reinforced sheet
material having excellent mechanical properties and drapeability
that can be produced at low cost; and a method for efficiently
producing these sheet materials in a short time and at low
cost.
[0032] The above-described thermoplastic-resin composite-material
molding has challenges to overcome, for example, how to impregnate
a reinforcing fiber material, such as carbon fibers or glass
fibers, with a thermoplastic resin material, such as polypropylene
resin, polyamide 6 resin, or polyetherimide resin in a short time,
without gaps (voids) but with excellent fiber distribution; and how
to perform accurate forming, i.e., how to form a three-dimensional
shape with no warpage.
[0033] In Patent Document 7, the plates are patterned only on the
material sides and are flat on the sides to be in contact with
press plates. Because the thickness of the plates is not uniform,
heat transfer to the material is uneven. Thus, uniform heating or
cooling is not performed during heating and cooling. This makes it
difficult to reduce the molding time and causes warpage due to
partially insufficient resin impregnation.
[0034] Typically, the press plates of a press are flat. Thus,
shaping molds are flat on the sides to be in contact with the press
plates and are patterned according to the shape of the molding on
the material sides. Therefore, the shaping molds are made of a
metal such as iron and formed to have a certain thickness so that
the patterned portions are not deformed during pressing.
Accordingly, the time for heating and cooling the shaping molds
themselves is required.
[0035] The known forming method using a heat-vacuum bag or the
like, as Patent Document 8, involves time-consuming operations such
as enclosing molds (shaping molds) with the bag and taking the
molds (shaping molds) out of the bag. Because the bag has a problem
in heat resistance, it is difficult to perform high-temperature
molding at 300.degree. or higher. In addition, because reuse of
such a bag is difficult, the bag has to be replaced every forming
processing. This leads to a problem in that the cost burden is
significant.
[0036] Therefore, an object of the present invention is to provide
a method for forming a thermoplastic-resin composite-material
molding having almost no gaps and having excellent fiber
distribution, in a short time without causing warpage.
Means for Solving the Problems
[0037] A multilayer thermoplastic-resin-reinforced sheet material
of the present invention is formed by stacking and integrating a
plurality of thermoplastic-resin-reinforced sheet materials each
formed of a reinforcing-fiber sheet material, consisting of a
plurality of reinforcing fibers arranged in a predetermined
direction, and a thermoplastic-resin sheet material that are joined
together. In each of the thermoplastic-resin-reinforced sheet
materials, one of the thermoplastic-resin sheet material and the
reinforcing-fiber sheet material is joined to each surface of the
other sheet material. The thermoplastic-resin-reinforced sheet
materials are each formed of a plurality of narrow
thermoplastic-resin-reinforced sheet materials arranged in a width
direction, the plurality of narrow thermoplastic-resin-reinforced
sheet materials each formed of a narrow reinforcing-fiber sheet
material, consisting of a plurality of reinforcing fibers arranged
in a predetermined direction, and a narrow thermoplastic-resin
sheet material that are joined together. The
thermoplastic-resin-reinforced sheet materials are each formed by
weaving a narrow thermoplastic-resin-reinforced sheet material
formed of a narrow reinforcing-fiber sheet material, consisting of
a plurality of reinforcing fibers arranged in a predetermined
direction, and a narrow thermoplastic-resin sheet material that are
joined together. The thermoplastic-resin-reinforced sheet materials
are stacked such that arrangement directions of the
reinforcing-fiber sheet materials are multiaxial. The
cross-sectional thickness of each reinforcing-fiber sheet material
is set within ten times the diameter of each reinforcing fiber. The
plurality of stacked thermoplastic-resin-reinforced sheet materials
are stitched together with an integration thermoplastic-resin fiber
tow composed of the same material as the thermoplastic-resin sheet
materials. The plurality of stacked thermoplastic-resin-reinforced
sheet materials are bonded together by thermal adhesion of the
thermoplastic-resin sheet materials. The plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by partial thermal adhesion of the thermoplastic-resin sheet
materials. The thermoplastic-resin-reinforced sheet materials each
have a bonding thermoplastic-resin material that is melted or
softened at a temperature lower than the melting temperature of the
thermoplastic-resin sheet material and deposited on one or both
surfaces of at least one of the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material. The
thermoplastic-resin-reinforced sheet materials are each formed of
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material that are bonded together with the bonding
thermoplastic-resin material. In the multilayer
thermoplastic-resin-reinforced sheet material, the
thermoplastic-resin-reinforced sheet materials each being formed of
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material that are bonded together with the bonding
thermoplastic-resin material, the bonding thermoplastic-resin
material being deposited on one or both surfaces of each
thermoplastic-resin-reinforced sheet material, the amount of
deposition per unit area of the bonding thermoplastic-resin
material for bonding the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material is different from the amount of
deposition per unit area of the bonding thermoplastic-resin
material deposited on one or both surfaces of each
thermoplastic-resin-reinforced sheet material. In the multilayer
thermoplastic-resin-reinforced sheet material, the
thermoplastic-resin-reinforced sheet materials each being formed of
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material that are bonded together with the bonding
thermoplastic-resin material, the bonding thermoplastic-resin
material being deposited on one or both surfaces of each
thermoplastic-resin-reinforced sheet material, the bonding
thermoplastic-resin material for bonding the reinforcing-fiber
sheet material and the thermoplastic-resin sheet material is a
resin different from the bonding thermoplastic-resin material
deposited on one or both surfaces of each
thermoplastic-resin-reinforced sheet material. The amount of
deposition per unit area of the bonding thermoplastic-resin
material is within 3% of the weight per unit area of the
reinforcing-fiber sheet material. The plurality of stacked
thermoplastic-resin-reinforced sheet materials are bonded together
by heat-melting or heat-softening the bonding thermoplastic-resin
material. The plurality of stacked thermoplastic-resin-reinforced
sheet materials are partially bonded together by partially
heat-melting or heat-softening the bonding thermoplastic-resin
material.
[0038] A method for producing a multilayer
thermoplastic-resin-reinforced sheet material of the present
invention includes: a sheet forming step for forming a
thermoplastic-resin-reinforced sheet material by joining a
reinforcing-fiber sheet material, consisting of a plurality of
reinforcing fibers arranged in a predetermined direction, and a
thermoplastic-resin sheet material, a stacking step for stacking a
plurality of the thermoplastic-resin-reinforced sheet materials in
a thickness direction, and an integration step for integrating the
plurality of stacked thermoplastic-resin-reinforced sheet
materials. In the sheet forming step, one of the
thermoplastic-resin sheet material and the reinforcing-fiber sheet
material is joined to each surface of the other sheet material. In
the sheet forming step, a narrow thermoplastic-resin-reinforced
sheet material is formed by joining a narrow reinforcing-fiber
sheet material, consisting of a plurality of reinforcing fibers
arranged in a predetermined direction, and a narrow
thermoplastic-resin sheet material, and a plurality of the narrow
thermoplastic-resin-reinforced sheet materials are arranged in a
width direction to form the thermoplastic-resin-reinforced sheet
material. In the sheet forming step, a narrow
thermoplastic-resin-reinforced sheet material is formed by joining
a narrow reinforcing-fiber sheet material, consisting of a
plurality of reinforcing fibers arranged in a predetermined
direction, and a narrow thermoplastic-resin sheet material, the
narrow thermoplastic-resin-reinforced sheet material is woven into
the thermoplastic-resin-reinforced sheet material. In the method
for forming the narrow thermoplastic-resin-reinforced sheet
material in the sheet forming step, after the
thermoplastic-resin-reinforced sheet material is formed by joining
the reinforcing-fiber sheet material, consisting of the plurality
of reinforcing fibers arranged in a predetermined direction, and
the thermoplastic-resin sheet material, the
thermoplastic-resin-reinforced sheet material is cut in a length
direction, at a desired interval in a width direction, to form the
plurality of narrow thermoplastic-resin-reinforced sheet materials.
In the stacking step, a plurality of the
thermoplastic-resin-reinforced sheet materials are stacked such
that the arrangement directions of the reinforcing fibers are
multiaxial. In the sheet forming step, the reinforcing-fiber sheet
material is formed into a sheet-like structure in which a plurality
of reinforcing fibers are arranged in a predetermined direction,
the cross-sectional thickness of the reinforcing-fiber sheet
material being set within ten times the diameter of each
reinforcing fiber. In the sheet forming step, the reinforcing-fiber
sheet material is formed from a wide and thin multi-filament spread
thread formed by continuously spreading, in a width direction, a
reinforcing fiber tow consisting of a plurality of filament-type
reinforcing fibers bundled together. The sheet forming step
includes a deposition step for depositing a bonding
thermoplastic-resin material that is melted or softened at a
temperature lower than the melting temperature of the
thermoplastic-resin sheet material on one or both surfaces of the
thermoplastic-resin-reinforced sheet material or the narrow
thermoplastic-resin-reinforced sheet material. The sheet forming
step includes a deposition step for depositing a bonding
thermoplastic-resin material that is melted or softened at a
temperature lower than the melting temperature of the
thermoplastic-resin sheet material to one or both surfaces of at
least one of the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material, and a joining step for joining
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material by disposing one of the reinforcing-fiber sheet
material and the thermoplastic-resin sheet material on one or both
surfaces of the other sheet material with the bonding
thermoplastic-resin material therebetween and by subjecting them to
heat or heat and pressure at a temperature lower than the melting
temperature of the thermoplastic-resin sheet material to melt or
soften the bonding thermoplastic-resin material. In the integration
step, the plurality of stacked thermoplastic-resin-reinforced sheet
materials are stitched together with an integration
thermoplastic-resin fiber tow composed of the same material as the
thermoplastic-resin sheet materials. In the integration step, the
plurality of stacked thermoplastic-resin-reinforced sheet materials
are bonded together by applying heat or heat and pressure to the
plurality of stacked thermoplastic-resin-reinforced sheet materials
to allow the thermoplastic-resin sheet materials in the respective
layers to be thermally adhered to the reinforcing-fiber sheet
materials in upper and lower layers in a thickness direction. In
the integration step, heat or heat and pressure is partially
applied to the plurality of stacked thermoplastic-resin-reinforced
sheet materials to allow the thermoplastic-resin sheet materials in
the respective layers to be thermally adhered to the
reinforcing-fiber sheet materials in upper and lower layers in a
thickness direction. In the integration step, heat or heat and
pressure is applied to the plurality of stacked
thermoplastic-resin-reinforced sheet materials at a temperature at
which the bonding thermoplastic-resin material is melted or
softened so as to bond the layers of the plurality of stacked
thermoplastic-resin-reinforced sheet materials with the bonding
thermoplastic-resin material. In the integration step, heat or heat
and pressure is partially applied to the plurality of stacked
thermoplastic-resin-reinforced sheet materials at a temperature at
which the bonding thermoplastic-resin material is melted or
softened so as to partially bond the layers of the plurality of
stacked thermoplastic-resin-reinforced sheet materials with the
bonding thermoplastic-resin material.
[0039] A thermoplastic-resin multilayer reinforced molding of the
present invention is obtained by cutting a multilayer
thermoplastic-resin-reinforced sheet material produced by the
above-described production method into pieces having a desired
size, stacking a desired number of the pieces in a shaping mold at
a desired angle, and performing hot press molding to allow the
reinforcing-fiber sheet material to be impregnated with the
thermoplastic-resin sheet material, and, in the case of
stitch-integration, with the integration thermoplastic-resin fiber
tow.
[0040] Another thermoplastic-resin multilayer reinforced molding of
the present invention is obtained by cutting a multilayer
thermoplastic-resin-reinforced sheet material produced by the
above-described production method into pieces having a desired
size, stacking a desired number of the pieces in a preforming mold
at a desired angle, performing hot press molding to allow the
reinforcing-fiber sheet material to be impregnated with the
thermoplastic-resin sheet material, and, in the case of
stitch-integration, with the integration thermoplastic-resin fiber
tow, to obtain a preformed laminate, heating the preformed laminate
to make it deformable, placing it in a shaping mold, and performing
press molding.
[0041] A method for forming a thermoplastic-resin
composite-material molding of the present invention is a method for
forming a thermoplastic-resin composite-material molding from a
molding material composed of a reinforcing fiber material and a
thermoplastic resin material. The method includes: disposing the
molding material between a pair of shaping molds formed to have a
uniform thickness at contact portions with respect to the molding
material; clamping the molding material between the shaping molds
in a manner that inside gas can be discharged from the periphery of
the molding material; placing the shaping molds clamping the
molding material therebetween between a pair of hot press molds
having contact surfaces formed to fit contact surfaces of the
shaping molds; performing hot pressing; placing the shaping molds
having gone through the hot pressing between a pair of cold press
molds having contact surfaces formed to fit the contact surfaces of
the shaping molds; and performing cold pressing to cure the
thermoplastic resin material melted and impregnated into the
layers. The molding material is clamped such that a space into
which gas inside the molding material is discharged is formed
between the shaping molds, and the space into which the gas is
discharged is brought into a vacuum or reduced pressure state. A
plurality of the shaping molds clamping the molding material are
stacked and subjected to hot pressing and cold pressing. Hot
pressing is sequentially performed using a plurality of hot press
molds having different temperatures. Cold pressing is sequentially
performed using a plurality of cold press molds having different
temperatures. The contact portions of the shaping molds are formed
to be thin. The shaping molds are composed of a carbon fiber carbon
composite material. The contact surfaces of the shaping molds to be
in contact with the molding material are treated with a release
treatment. In the molding material, the thermoplastic resin
material serving as a matrix is unevenly distributed between layers
of the reinforcing fiber materials.
ADVANTAGES
[0042] The multilayer thermoplastic-resin-reinforced sheet material
of the present invention is formed by stacking a plurality of
thermoplastic-resin-reinforced sheet materials each formed of a
reinforcing-fiber sheet material, consisting of a plurality of
reinforcing fibers arranged in a predetermined direction in a
sheet-like structure, and a thermoplastic-resin sheet material that
are joined together. Therefore, when the multilayer
thermoplastic-resin-reinforced sheet material is subjected to hot
pressing to obtain a composite-material molding, because, in each
of the stacked thermoplastic-resin-reinforced sheet materials, the
thermoplastic-resin sheet material serving as a matrix (base
material) is joined to the reinforcing-fiber sheet material, the
thermoplastic resin can be easily impregnated into the reinforcing
fibers. That is, unlike forming in which the entire fabric composed
of multiaxially arranged multilayer reinforcing fiber tows is
impregnated with a thermoplastic resin, because the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material are disposed in each layer, the distance over which the
thermoplastic resin flows between the reinforcing fibers for
impregnation is reduced. Accordingly, a molding having few voids
(gaps) can be formed in a short time.
[0043] Because the thermoplastic-resin-reinforced sheet material is
formed of the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material that are joined together, the
shape of the sheet is maintained and handling is easy. Furthermore,
a state in which the distribution of the reinforcing fibers is
maintained can be kept.
[0044] In addition, because the thermoplastic-resin-reinforced
sheet material is formed of the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material that are joined
together, unlike a prepreg sheet in which reinforcing fibers are
impregnated with a thermoplastic resin material, the drapeability
of the sheet is excellent. The use of the narrow
thermoplastic-resin-reinforced sheet materials further improves the
drapeability of the sheet and the conformability to a
three-dimensional shape.
[0045] In the case of the thermoplastic-resin-reinforced sheet
material formed by joining one of the thermoplastic-resin sheet
material and the reinforcing-fiber sheet material to each surface
of the other sheet material, because the sheet materials composed
of the same material are joined to both surfaces, the thermoplastic
reinforced sheet material is not curled and deformed toward one of
the surfaces and can maintain a flat shape.
[0046] In particular, in the case of the
thermoplastic-resin-reinforced sheet material formed by joining the
reinforcing-fiber sheet material to each surface of the
thermoplastic-resin sheet material, when the composition ratios of
both sheet materials are set to predetermined values, half the
reinforcing-fiber sheet material is joined to each surface of the
thermoplastic-resin sheet material, and the thickness of the
reinforcing-fiber sheet material can be set to small. This reduces
the impregnation distance during impregnation of the
reinforcing-fiber sheet material with the thermoplastic resin.
Accordingly, a high-quality molding having fewer gaps, such as
voids, can be formed in a shorter time.
[0047] When the thickness of the thermoplastic-resin-reinforced
sheet material is to be reduced, because the thickness of the
reinforcing-fiber sheet material can be reduced more easily than
that of the thermoplastic-resin sheet material, by joining thin
reinforcing-fiber sheet materials to both surfaces of the
thermoplastic-resin sheet material, the thickness of the
thermoplastic-resin-reinforced sheet material can be further
reduced.
[0048] The multilayer thermoplastic-resin-reinforced sheet material
is formed by stacking a plurality of thermoplastic-resin-reinforced
sheet materials. In the case of the multilayer
thermoplastic-resin-reinforced sheet material formed by stacking
the thermoplastic-resin-reinforced sheet materials such that their
reinforcing directions are the same, a unidirectionally reinforced,
thick, and high-quality sheet material or molding can be obtained
in a short time. In the case of the multilayer
thermoplastic-resin-reinforced sheet material formed by stacking
the thermoplastic-resin-reinforced sheet materials such that their
reinforcing directions are different, a multi-directionally
reinforced, thick, and high-quality sheet material or molding can
be obtained in a short time.
[0049] Furthermore, by using the thermoplastic-resin-reinforced
sheet material formed by weaving a narrow
thermoplastic-resin-reinforced sheet material, a single sheet
material can provide biaxial reinforcing directions, and a sheet
material having excellent handling property and drapeability can be
obtained.
[0050] In addition, because the cross-sectional thickness of each
reinforcing-fiber sheet material is set within ten times the
diameter of each reinforcing fiber, the distance over which the
thermoplastic resin flows between the reinforcing fibers for
impregnation is further reduced. Thus, forming processing in a
short time can be achieved. Moreover, by further reducing the
distance over which the thermoplastic resin flows between the
reinforcing fibers, random orientation of the reinforcing fibers
due to flow of the resin is suppressed and the uniform distribution
of the reinforcing fibers is maintained. Thus, voids (gaps), into
which the resin does not flow, can be further reduced.
[0051] Furthermore, because the multilayer
thermoplastic-resin-reinforced sheet material is formed of the
plurality of thermoplastic-resin-reinforced sheet materials stacked
and stitched together with the integration thermoplastic-resin
fiber tow, or formed of the thermoplastic-resin sheet materials
bonded together by thermal adhesion, the sheet material has
excellent drapeability. When the sheets are bonded together, by
bonding them partially, not entirely, the drapeability can be
further improved.
[0052] The multilayer thermoplastic-resin-reinforced sheet material
is formed of the plurality of stacked
thermoplastic-resin-reinforced sheet materials stitched together
with the integration thermoplastic-resin fiber tow composed of the
same material as the thermoplastic resin material. Therefore, when
the multilayer thermoplastic-resin-reinforced sheet material is
subjected to hot pressing to obtain a composite-material molding,
the integration thermoplastic-resin fiber tow is also melted and
integrated with the thermoplastic resin material and exists as the
base material (matrix). Furthermore, melting of the integration
thermoplastic-resin fiber tow allows the reinforcing fibers to be
unraveled more easily and the fibers to be uniformly distributed.
That is, unlike the known technique, there is no situation in which
a thread or a fiber having reinforcing effect, used for integration
and existing in the base material (matrix), degrades the mechanical
properties of the composite-material molding or inhibits unraveling
of the reinforcing fibers.
[0053] Furthermore, as a result of the integration
thermoplastic-resin fiber tow being melted and constituting the
base material (matrix), the surface of the molded
composite-material molding becomes smooth. In other words, if, as
in the known technique, a thread or a fiber having a reinforcing
effect for integration is used, the thread or the fiber having a
reinforcing effect remains on the surface of the composite-material
molding. In particular, when the layers are thin, the surface
becomes more uneven because of the influence of the thread or the
fiber having a reinforcing effect.
[0054] The multilayer thermoplastic-resin-reinforced sheet material
is formed of the plurality of stacked
thermoplastic-resin-reinforced sheet materials that are bonded
together by thermal adhesion. Because this does not require a
thread for integration, which is used in the known technique, a
composite-material molding formed of the multilayer
thermoplastic-resin-reinforced sheet material maintains the surface
smoothness and the mechanical properties.
[0055] The thermoplastic-resin-reinforced sheet material has the
bonding thermoplastic-resin material that is melted or softened at
a temperature lower than the melting temperature of the
thermoplastic-resin sheet material and is deposited on one or both
surfaces of at least one of the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material. Thus, when the
thermoplastic-resin-reinforced sheet material is cut and stacked in
the required orientations, by applying heat or heat and pressure at
a temperature at which the bonding thermoplastic-resin material is
melted or softened, the layers of the stacked
thermoplastic-resin-reinforced sheet materials can be bonded
together with the bonding thermoplastic-resin material. This eases
handling of the stacked thermoplastic-resin-reinforced sheet
materials, and when placed in the shaping molds, the stacked
thermoplastic-resin-reinforced sheet materials can be easily placed
in the shaping molds while the reinforcing directions of the
reinforcing fibers and the arrangement state of the reinforcing
fibers are maintained.
[0056] In addition, the thermoplastic-resin-reinforced sheet
material is formed by joining one of the reinforcing-fiber sheet
material and the thermoplastic-resin sheet material to one or both
surfaces of the other sheet material with the bonding
thermoplastic-resin material. Therefore, the thermoplastic-resin
sheet material is securely joined to the reinforcing-fiber sheet
material. Thus, the shape of the thermoplastic-resin-reinforced
sheet material is maintained and handling becomes easy. Moreover,
the arrangement state of the reinforcing fibers constituting the
reinforcing-fiber sheet material can be maintained.
[0057] In addition, in the thermoplastic-resin-reinforced sheet
material, because the amount of deposition per unit area of the
bonding thermoplastic-resin material for bonding the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material and the amount of deposition per unit area of the bonding
thermoplastic-resin material deposited on one or both surfaces of
the thermoplastic-resin-reinforced sheet material are different,
or, because the bonding thermoplastic-resin material for bonding
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material and the bonding thermoplastic-resin material
deposited on one or both surfaces of the
thermoplastic-resin-reinforced sheet material are different, it is
possible to obtain a multilayer thermoplastic-resin-reinforced
sheet material in which the adhesiveness of the reinforcing-fiber
sheet material to the thermoplastic-resin sheet material layer and
the adhesiveness between the thermoplastic-resin-reinforced sheet
materials are different. Therefore, the layers of the
thermoplastic-resin-reinforced sheet material can be shifted from
each other while the arranged state and distributed state of the
reinforcing fibers are maintained by joining the reinforcing-fiber
sheet material to the thermoplastic-resin sheet material. That is,
the multilayer thermoplastic-resin-reinforced sheet material is
formed of a plurality of thermoplastic-resin-reinforced sheet
materials bonded together and is easy to handle. At the same time,
the multilayer thermoplastic-resin-reinforced sheet material can,
when placed in the shaping molds for forming, conform to the shape
of the molds at curved portions by shifting the layers of the
thermoplastic-resin-reinforced sheet materials from each other
without loosing the arranged state and distribution state of the
reinforcing fibers, and has a further improved drapeability to a
complex shape.
[0058] Furthermore, when the amount of deposition per unit area of
the bonding thermoplastic-resin material in the
thermoplastic-resin-reinforced sheet material is within 3% of the
weight per unit area of the reinforcing-fiber sheet material, the
influence of the bonding thermoplastic-resin material on the
mechanical properties and thermal properties of a molding become
negligible.
[0059] In the method for producing the multilayer
thermoplastic-resin-reinforced sheet material of the present
invention, first, a sheet-like thermoplastic-resin-reinforced sheet
material is formed by joining the reinforcing-fiber sheet material,
consisting of the plurality of reinforcing fibers arranged in a
predetermined direction in a sheet-like structure, and the
thermoplastic-resin sheet material. Then, a plurality of the
thermoplastic-resin-reinforced sheet materials are stacked in the
thickness direction. Thus, the reinforcing fibers and the
thermoplastic resin materials can be arranged in the respective
layers with high production efficiency.
[0060] Because the thermoplastic-resin-reinforced sheet material
has a certain width, the thermoplastic-resin-reinforced sheet
materials in the respective layers of the multilayer
thermoplastic-resin-reinforced sheet material can be efficiently
formed.
[0061] By joining the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material, random orientation of the
reinforcing fibers constituting the reinforcing-fiber sheet
material is suppressed and the fiber straightness is maintained.
Moreover, because the sheet-shape stability of the
thermoplastic-resin-reinforced sheet material improves, handling
becomes easy.
[0062] The narrow thermoplastic-resin-reinforced sheet material can
be efficiently produced by joining a reinforcing-fiber sheet
material, consisting of a plurality of reinforcing fibers arranged
in a predetermined direction in a narrow sheet-like structure, and
a narrow sheet-like thermoplastic-resin sheet material. A plurality
of the narrow thermoplastic-resin-reinforced sheet materials can be
more efficiently produced by producing a wide
thermoplastic-resin-reinforced sheet material and cutting the
thermoplastic-resin-reinforced sheet material in the length
direction at a desired interval in the width direction.
[0063] Furthermore, when the thermoplastic-resin-reinforced sheet
material is produced, by using the multi-filament spread threads of
the reinforcing fiber tow as the reinforcing-fiber sheet material,
a sheet-like structure formed of a plurality of reinforcing fibers
arranged in a predetermined direction, the cross-sectional
thickness thereof being within ten times the diameter of the
reinforcing fiber, can be efficiently formed. Because large
fineness fiber tows, whose material price is low, can be used,
low-cost production is possible.
[0064] As a method for integrating the plurality of stacked
thermoplastic-resin-reinforced sheet materials, stitch integration
with a stitching thread or bonding integration by thermal adhesion
is performed. Thus, high-speed integration of the stacked
thermoplastic-resin-reinforced sheet materials is performed. In
particular, in the case of bonding integration by thermal adhesion,
because the thermoplastic-resin sheet material is not melted to be
impregnated into the reinforcing fibers, the layers can be bonded
together in a short time.
[0065] In the sheet forming step, heat or heat and pressure is
applied at a temperature lower than the melting temperature of the
thermoplastic-resin sheet material to join the reinforced sheet
material and the thermoplastic-resin sheet material with the
bonding thermoplastic-resin material. Because heating is performed
at a temperature lower than the melting temperature of the
thermoplastic-resin sheet material, shrinkage of the
thermoplastic-resin sheet material associated with heating hardly
occurs. Therefore, it is possible to obtain a
thermoplastic-resin-reinforced sheet material in which the
straightness of the reinforcing fibers, the quality of the
thermoplastic-resin sheet material, etc. are maintained.
[0066] Because of the method in which the bonding
thermoplastic-resin material is deposited on the
thermoplastic-resin sheet material, the surface of the
thermoplastic-resin sheet material is smooth. This makes it easy to
uniformly deposit a small amount of bonding thermoplastic-resin
material on the entire sheet, and also improves the adhesiveness
between the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material.
[0067] Furthermore, because the reinforced sheet material and the
thermoplastic-resin sheet material are joined with the bonding
thermoplastic-resin material, the thermoplastic-resin sheet
material does not have to be melted and impregnated into the
reinforcing fibers constituting the reinforcing-fiber sheet
material to be thermally adhered thereto. Thus, equipment for
applying heat or heat and pressure can be made compact.
Furthermore, equipment for continuously processing a wide
thermoplastic-resin-reinforced sheet material at a high speed can
be installed relatively easily and at low cost. During application
of heat or heat and pressure to join the reinforced sheet material
and the thermoplastic-resin sheet material with the bonding
thermoplastic-resin material, a release sheet material may be
required. In such a case, because the heating temperature is low,
release paper or the like can be used as the release sheet
material. Thus, a wide thermoplastic-resin-reinforced sheet
material can be obtained at a low running cost.
[0068] By heat-melting the bonding thermoplastic-resin material to
bond the plurality of stacked thermoplastic-resin-reinforced sheet
materials, the stacked thermoplastic-resin-reinforced sheet
materials can be integrated at high speed. Because bonding
integration with the bonding thermoplastic-resin material does not
require the thermoplastic-resin sheet material to be melted and
impregnated into the reinforcing fibers, the layers can be bonded
together in a short time.
[0069] Because the reinforcing-fiber sheet material is not
impregnated with the thermoplastic-resin sheet material, the
drapeability of the thermoplastic-resin-reinforced sheet material
is maintained. Thus, a multiaxial or multiaxial multilayer sheet
material having excellent conformability to a three-dimensional
shape can be obtained.
[0070] Although the thermoplastic-resin multilayer reinforced
molding of the present invention is formed of the multilayer
thermoplastic-resin-reinforced sheet material, because the
multilayer thermoplastic-resin-reinforced sheet material is
stitched or bonded together, handling, as well as cutting and
stacking for production of a molding, is easy. Furthermore, because
the multilayer thermoplastic-resin-reinforced sheet material is
formed of the plurality of stacked thermoplastic-resin-reinforced
sheet materials and has a certain thickness, the number of layers
to be stacked to produce a molding can be reduced. That is, the
thermoplastic-resin multilayer reinforced molding is a
labor-saving, low-cost molding.
[0071] Furthermore, because the multilayer
thermoplastic-resin-reinforced sheet material is used, during
production of moldings, the reinforcing-fiber sheet material is
impregnated with the resin in a short time, and the resulting
moldings have few voids (gaps) and exhibit excellent fiber
straightness, fiber distribution, and surface smoothness. That is,
the thermoplastic-resin multilayer reinforced molding of the
present invention is a high-quality molding.
[0072] The thermoplastic-resin multilayer reinforced molding is
formed of a preformed laminate which is preliminarily formed from
the multilayer thermoplastic-resin-reinforced sheet material. In a
method in which a plate-shaped preformed laminate, which is easy to
be molded and typically high quality, is preliminarily formed,
heated, and then subjected to press-molding to obtain a molding,
the heating process and the molding process can be divided. Thus, a
molding having a three-dimensional shape can be efficiently
produced in a short time. That is, the thermoplastic-resin
multilayer reinforced molding according to the present invention is
high quality and produced in a shorter time.
[0073] In the method for forming a thermoplastic-resin
composite-material molding according to the present invention,
because of the above-described configuration, the molding material,
composed of the reinforcing fiber material and the thermoplastic
resin material, is heated and cooled while being subjected to
pressure so that the thermoplastic resin material is uniformly
melted, impregnated, and cured. Thus, a thermoplastic-resin
composite-material molding almost free from gaps, having excellent
fiber distribution, and having no warpage can be formed.
[0074] That is, the molding material is disposed and clamped
between a pair of shaping molds whose contact portions with respect
to the molding material have a uniform thickness. Then, the shaping
molds are placed between a pair of hot press molds having contact
surfaces formed to fit the contact surfaces of the shaping molds,
and are subjected to hot pressing. Thus, heat from the hot press
molds is uniformly conducted to the entire molding material through
the contact portions of the shaping molds having a uniform
thickness.
[0075] Thus, the entire thermoplastic resin material constituting
the molding material is more uniformly melted and impregnated.
Furthermore, because the molding material is sandwiched between the
shaping molds and clamped in such a manner that the internal gas
can be discharged from the periphery of the molding material, the
gas in the molding material is discharged along with impregnation
of the thermoplastic resin material. Thus, the thermoplastic resin
material is impregnated without generating gaps. In addition,
because the molding material is always clamped between the contact
surfaces of the shaping molds, the arrangement of the reinforcing
fiber material is not disturbed because of the flow of the
thermoplastic resin material during impregnation. Thus, the fiber
distribution is maintained.
[0076] The shaping molds having undergone hot pressing are then
placed between a pair of cold press molds having contact surfaces
formed to fit the contact surfaces of the shaping molds and are
subjected to cold pressing through the contact portions of the
shaping molds having a uniform thickness. Thus, the entire molding
material can be uniformly cooled, whereby the melted and
impregnated thermoplastic resin material can be evenly cured and
uniformly molded. Thus, an excellent molding having no warpage can
be produced.
[0077] By performing heating and cooling using different press
molds, these processes can be efficiently performed. Thus, compared
to the case in which these processes are performed using one press
mold, the molding time can be significantly reduced.
[0078] By clamping the molding material such that a space into
which gas inside the molding material is discharged is formed
between the shaping molds, and by bringing the space into which the
gas is discharged into a vacuum or reduced pressure state, during
melting and impregnation of the thermoplastic resin material,
impregnation of the thermoplastic resin material into the
reinforcing fiber material is accelerated and the impregnation time
can be significantly reduced. Moreover, gaps in the resulting
molding can be reduced, and a high-quality molding can be
obtained.
[0079] By evacuating or reducing the pressure inside the shaping
molds, atmospheric pressure acts on the entire outer surface of the
shaping molds. Thus, when the shaping molds are placed in the hot
press mold or the cold press mold, the molding material sandwiched
between the shaping molds can always be kept in a clamped state,
making it possible to obtain a high-quality molding in which the
straightness, distribution, etc., of the reinforcing fiber material
are maintained.
[0080] By stacking a plurality of shaping molds sandwiching the
molding materials and subjecting them to hot pressing and cold
pressing, a plurality of thermoplastic-resin composite-material
moldings can be formed simultaneously. Thus, the molding time can
be reduced. When the plurality of shaping molds are stacked, by
making the shaping molds have one common gas-discharging space and
evacuating or reducing the pressure, the shaping molds can be
efficiently evacuated or depressurized.
[0081] By sequentially performing hot pressing using a plurality of
hot press molds having different temperatures or by sequentially
performing a cooling/heating process using a plurality of cold
press molds having different temperatures, hot pressing or cold
pressing can be gradually performed. This enables to control
heating or cooling of the thermoplastic resin material, whereby
impregnation into layers formed of the arranged reinforcing fiber
materials is smoothly performed and sudden shrinkage of the
thermoplastic resin material is prevented. Thus, a high-quality
thermoplastic-resin composite-material molding having excellent
fiber straightness can be obtained.
[0082] Because the contact portions of the shaping molds are thin,
the thermal conductivity of the shaping molds during heating and
cooling is improved. Thus, the molding time can be reduced.
[0083] By making the shaping molds from the carbon fiber carbon
composite material, which hardly exhibits thermal deformation
during heating and cooling and has excellent thermal conductivity,
a thermoplastic-resin composite-material molding almost free from
warpage can be formed.
[0084] In addition, by applying a release treatment to the contact
surfaces of the shaping molds to be brought into contact with the
molding material or by providing a release sheet material on a
portion of the molding material to be brought into contact with the
shaping molds, the formed molding can be easily removed from the
shaping molds.
[0085] When, a material in which the thermoplastic resin materials
serving as a matrix is unevenly distributed between layers of the
reinforcing fiber materials is used as the molding material,
because the thermoplastic resin materials are distributed in the
layer direction, the thermoplastic resin materials are
simultaneously heated and melted, and impregnated in the direction
perpendicular to the layer direction during hot pressing. Thus,
smooth impregnation can be performed. Furthermore, because the
thermoplastic resin materials are impregnated from both sides of
each layer, the air inside the layer is efficiently discharged in
the direction in which the reinforcing fiber materials are
arranged. Thus, almost no air remains in the layer.
[0086] In addition, by forming the molding material by stacking a
plurality of thermoplastic-resin-reinforced sheet materials each
formed of a reinforcing-fiber sheet material, consisting of a
plurality of reinforcing fibers arranged in a predetermined
direction in a sheet-like structure, and a thermoplastic-resin
sheet material joined to one or both surfaces of the
reinforcing-fiber sheet material, an easy-to-produce molding
material having excellent mechanical properties and drapeability
during molding can be used.
BEST MODES FOR CARRYING OUT THE INVENTION
[0087] Embodiments of the present invention will be described in
detail below. Although the embodiments described below include
various technical limitations since they are preferable specific
examples for implementing the present invention, the present
invention is not limited to these embodiments unless otherwise
stated in the following description.
[0088] FIG. 1 is a schematic view showing a part of a multilayer
thermoplastic-resin-reinforced sheet material 11 according to an
embodiment of the present invention. The multilayer
thermoplastic-resin-reinforced sheet material 11 is formed by
stacking thermoplastic-resin-reinforced sheet materials 21A to 21D
each formed of a reinforcing-fiber sheet material 31, consisting of
a plurality of reinforcing fibers 31f arranged in a sheet-like
structure, and a thermoplastic-resin sheet material 41 joined to a
surface thereof, and integrating them with an integration
thermoplastic-resin fiber tow 51 composed of the same material as
the thermoplastic-resin sheet material 41. In FIG. 1, the
thermoplastic-resin-reinforced sheet materials 21A to 21D are
stacked such that the reinforcing fibers in the
thermoplastic-resin-reinforced sheet materials are oriented in
different axial directions. Then, the
thermoplastic-resin-reinforced sheet materials are integrated with
the integration thermoplastic-resin fiber tow 51.
[0089] The reinforcing-fiber sheet materials 31 are each formed of
a plurality of reinforcing fiber tows, each consisting of a
plurality of reinforcing fibers bundled together with a sizing
agent or the like so as not to be unraveled, arranged in a
sheet-like structure, for example. Examples of the reinforcing
fibers 31f include high-strength, high-modulus inorganic fibers
used for FRPs, such as carbon fiber, glass fiber, ceramic fiber,
polyoxymethylene fiber, and aromatic polyamide fiber, or organic
fibers. Fiber tows of the aforementioned fibers may be used in
combination. The fineness is not specified.
[0090] The thermoplastic-resin sheet materials 41 serve as a base
material (matrix) resin, and may be composed of polypropylene,
polyethylene, polystyrene, polyamide (nylon 6, nylon 66, nylon 12,
etc.), polyacetal, polycarbonate, acrylonitrile-butadiene-styrene
copolymer (ABS), polyethylene terephthalate, polybutylene
terephthalate, polyetherimide, polyethersulfone, polyphenylene
sulfide, polyetherketone, or polyetheretherketone. Alternatively, a
polymer alloy composed of two or more of the aforementioned
thermoplastic resins may be used as the base material (matrix)
resin.
[0091] The integration thermoplastic-resin fiber tow 51 is a
thermoplastic resin fiber composed of the same material as the
matrix resin used. The "same material" may be a material whose main
polymer has the same chemical composition, and its molecular
weight, crystallinity, type of compounds, etc. may be different.
Because the resin is heat-melted when a molding is to be obtained,
as long as the chemical compositions of the main polymers are the
same, the thermoplastic-resin sheet materials 41 and the
integration thermoplastic-resin fiber tow 51 are melted, combined,
and become the base material (matrix).
[0092] Although, when the thermoplastic-resin sheet materials 41
are made of a polymer alloy, it is preferable that an integration
thermoplastic-resin fiber tow made of the same polymer alloy resin
be used, an integration thermoplastic-resin fiber tow made of one
of the thermoplastic resins combined to make the polymer alloy
resin may be used. Although the composition ratio of the
thermoplastic resins constituting the polymer alloy is locally and
slightly changed as a result of heat-melting for obtaining a
molding, because the thermoplastic-resin sheet materials 41 serving
as the base material (matrix) and the integration
thermoplastic-resin fiber tow 51 are melted and combined and the
shape of the fibers disappears, a molding having improved
distribution of the reinforcing fibers and surface smoothness can
be obtained without lowering mechanical properties.
[0093] Although the multilayer thermoplastic-resin-reinforced sheet
material 11 shown in FIG. 1 is formed by stacking four
thermoplastic-resin-reinforced sheet materials 21A to 21D, the
number of layers is not limited to four, but may be two or more. At
this time, the reinforcing directions of these
thermoplastic-resin-reinforced sheet materials may be either the
same or different. They may be stacked in any orientations. In the
case of FIG. 1, the thermoplastic-resin-reinforced sheet material
21A is fiber-reinforced in 0.degree. direction, the
thermoplastic-resin-reinforced sheet material 21B is
fiber-reinforced in 45.degree. direction, the
thermoplastic-resin-reinforced sheet material 21C is
fiber-reinforced in 90.degree. direction, and the
thermoplastic-resin-reinforced sheet material 21D is
fiber-reinforced in -45.degree. direction.
[0094] FIGS. 2 to 4 are schematic views showing a part of a
thermoplastic-resin-reinforced sheet material 21 according to
embodiments of the present invention. The
thermoplastic-resin-reinforced sheet material 21 in FIG. 2 consists
of the reinforcing-fiber sheet material 31 formed of a plurality of
reinforcing fiber tows 31t, each consisting of a plurality of
reinforcing fibers 31f bundled together with a sizing agent or the
like, arranged in a width direction in a sheet-like structure and
the thermoplastic-resin sheet material 41 joined to a surface
thereof. The thermoplastic-resin-reinforced sheet material 21 in
FIG. 3 has a structure in which one of the reinforcing-fiber sheet
material 31 and the thermoplastic-resin sheet material 41 is joined
to each surface of the other sheet material. In FIG. 3A, the
reinforcing-fiber sheet material 31 is joined to each surface of
the thermoplastic-resin sheet material 41, and in FIG. 3B, the
thermoplastic-resin sheet material 41 is joined to each surface of
the reinforcing-fiber sheet material 31.
[0095] The thermoplastic-resin-reinforced sheet material 21 is
formed by joining the reinforcing-fiber sheet material 31 formed of
a plurality of reinforcing fiber tows, each consisting of a
plurality of reinforcing fibers bundled together with a sizing
agent or the like so as not to be unraveled, arranged in a
sheet-like structure and the thermoplastic-resin sheet material 41.
Therefore, not only the reinforcing fiber tows are kept arranged
and are not unraveled, but also the reinforcing fibers constituting
the reinforcing fiber tows are not unraveled because of the effect
of the sizing agent deposited thereon. Thus, random orientation of
the fibers is prevented and fray is less likely to be
generated.
[0096] Herein, "join" means to integrate the reinforcing-fiber
sheet material and the thermoplastic-resin sheet material in a
manner that they do not come apart by bonding the
thermoplastic-resin sheet material to the entirety or several
portions of one or both surfaces of the reinforcing-fiber sheet
material by thermal adhesion, or by thinly applying an adhesive not
affecting the mechanical properties or the like of a finished
molding. Although the surface layer portion of the
reinforcing-fiber sheet material may be slightly impregnated with
the thermoplastic-resin sheet material when the thermoplastic-resin
sheet material is thermally adhered to the reinforcing-fiber sheet
material, even in such a case, the sheets exhibit sufficient
drapeability and are in a joined state.
[0097] In the thermoplastic-resin sheet material shown in FIG. 3,
one of the thermoplastic-resin sheet material and the
reinforcing-fiber sheet material is joined to each surface of the
other sheet material. Because the sheet materials composed of the
same material are joined to both surfaces, the thermoplastic
reinforced sheet material is not curled toward one of the surfaces.
Although deformation, such as curl, tends to occur as the thickness
of the thermoplastic-resin-reinforced sheet material is reduced, by
employing the structure shown in FIG. 3, the sheet material can be
maintained flat.
[0098] In the case of the thermoplastic-resin-reinforced sheet
material in which the reinforcing-fiber sheet materials are joined
to both surfaces of the thermoplastic-resin sheet material as shown
in FIG. 3A, when the composition ratio of these sheet materials is
set to a predetermined value, half the amount of the
reinforcing-fiber sheet material is joined to each surface of the
thermoplastic-resin sheet material. Thus, the thickness of the
reinforcing-fiber sheet material can be set to small. This reduces
the impregnation distance during impregnation of the
reinforcing-fiber sheet material with the thermoplastic resin.
[0099] When the thickness of the thermoplastic-resin-reinforced
sheet material is to be reduced, the thicknesses of the
thermoplastic-resin sheet material and the reinforcing-fiber sheet
material need to be reduced. Because the thickness of the
reinforcing-fiber sheet material can be reduced more easily than
that of the thermoplastic-resin sheet material, by joining thin
reinforcing-fiber sheet materials to both surfaces of the
thermoplastic-resin sheet material, the thickness of the
thermoplastic-resin-reinforced sheet material can be further
reduced and the impregnation distance can be reduced. Accordingly,
a high-quality molding having fewer gaps, such as voids, can be
obtained in a shorter time.
[0100] The thermoplastic-resin-reinforced sheet material 21 shown
in FIG. 4 has a configuration in which a plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H, each formed of
a narrow reinforcing-fiber sheet material 31, consisting of a
plurality of reinforcing fibers 31f, and a narrow
thermoplastic-resin sheet material 41 joined to a surface thereof,
are arranged in a width direction in a sheet-like structure. By
arranging the plurality of narrow thermoplastic-resin-reinforced
sheet materials 21H both in the width direction and the thickness
direction in this manner, a unidirectionally reinforced
thermoplastic-resin-reinforced sheet material is obtained. By
weaving the narrow thermoplastic-resin-reinforced sheet materials
21H, a thermoplastic-resin-reinforced sheet material reinforced
bidirectionally, for example, in 0.degree. direction and 90.degree.
direction, can be obtained.
[0101] Although, in each narrow thermoplastic-resin-reinforced
sheet material 21H shown in FIG. 4, the narrow thermoplastic-resin
sheet material 41 is joined to a surface of the narrow
reinforcing-fiber sheet material 31, the narrow thermoplastic-resin
sheet material may be joined to each surface of the narrow
reinforcing-fiber sheet material. Furthermore, the narrow
reinforcing-fiber sheet material may be joined to each surface of
the narrow thermoplastic-resin sheet material.
[0102] By setting the thickness of the reinforcing-fiber sheet
materials 31 within ten times the diameter of the reinforcing
fibers 31f, when a molding is formed, the distance for impregnation
over which the thermoplastic-resin sheet material flows between the
reinforcing fibers is further reduced. The diameter of a single
thread of carbon fiber, which is a typical reinforcing fiber of
composite materials, is 0.005 to 0.007 mm. Accordingly, the
thickness of the reinforcing-fiber sheet materials 31 is in the
range from 0.05 to 0.07 mm. According to a model calculation
disclosed in Non-Patent Document 1, it is expected that the
reinforcing fiber tows are impregnated with a thermoplastic-resin
sheet material within a few seconds. Thus, forming processing in a
short time can be achieved. In addition, by further reducing the
distance over which the thermoplastic-resin sheet material flows
between the reinforcing fibers, random orientation of the
reinforcing fibers due to resin flow is suppressed. Thus, a molding
having improved distribution of the reinforcing fibers and having
few voids (gaps) can be obtained.
[0103] To set the thickness of the reinforcing-fiber sheet
materials 31 within ten times the diameter of the reinforcing
fibers 31f, a method using a fiber tow consisting of a small number
of fibers, a method in which a fiber tow is spread, etc., may be
employed. In the method in which a fiber tow is spread, a fiber tow
consisting of a large number of fibers (a large fineness fiber tow)
can be spread in a wide and thin layer. Because the material cost
of the large fineness fiber tow is relatively low, a low-cost
molding can be obtained. The shape of the multi-filament spread
thread is stable because of the effect of the sizing agent or the
like used in a filament state.
[0104] The thickness or weight of the thermoplastic-resin sheet
materials 41 joined to the reinforcing-fiber sheet materials 31 is
determined in relation to the weight (fiber weight per unit area)
of the reinforcing-fiber sheet material, the fiber volume content
of a finished molding, and the like.
[0105] Another thermoplastic-resin-reinforced sheet material used
in a multilayer thermoplastic-resin-reinforced sheet material will
now be described. FIG. 5 is a schematic view showing a part of a
thermoplastic-resin-reinforced sheet material 22 according to an
embodiment of the present invention.
[0106] The thermoplastic-resin-reinforced sheet material 22 has a
configuration in which a thermoplastic-resin sheet material 42 is
joined to a surface of a sheet-like reinforcing-fiber sheet
material 32 formed of a plurality of reinforcing fiber tows 32t,
each consisting of a plurality of reinforcing fibers 32f bundled
together with a sizing agent or the like, arranged in the width
direction, and a bonding thermoplastic-resin material 52 melted or
softened at a temperature lower than the melting temperature of the
thermoplastic-resin sheet material 42 is deposited on the surface
of the thermoplastic-resin sheet material 42 to which the
reinforcing-fiber sheet material 32 is not joined.
[0107] The bonding thermoplastic-resin material may be deposited on
the surface of the reinforcing-fiber sheet material to which the
thermoplastic-resin sheet material is not joined. The
thermoplastic-resin sheet material may be joined to each surface of
the reinforcing-fiber sheet material. In such a case, the bonding
thermoplastic-resin material is deposited on the surface of one or
both of the thermoplastic-resin sheet materials to which the
reinforcing-fiber sheet material is not joined. Furthermore, the
reinforcing-fiber sheet material may be joined to each surface of
the thermoplastic-resin sheet material. In such a case, the bonding
thermoplastic-resin material is deposited on the surface of one or
both of the reinforcing-fiber sheet materials to which the
thermoplastic-resin sheet material is not joined.
[0108] Because the bonding thermoplastic-resin material 52 is
deposited on the surface, when the thermoplastic-resin-reinforced
sheet material is cut into pieces and stacked in the required
orientations, by applying heat or heat and pressure at a
temperature at which the bonding thermoplastic-resin material is
melted or softened, the layers of the stacked
thermoplastic-resin-reinforced sheet materials can be bonded
together with the bonding thermoplastic-resin material. That is,
handling of the stacked thermoplastic-resin-reinforced sheet
materials becomes easy, and, when placed in a shaping metal mold,
the stacked thermoplastic-resin-reinforced sheet materials can be
easily placed in metal molds while the reinforcing directions of
the reinforcing fibers and the arrangement of the reinforcing
fibers are maintained.
[0109] Typically, a reinforcing-fiber sheet material constituting a
thermoplastic-resin-reinforced sheet material is formed of
reinforcing fiber tows each consisting of a plurality of
reinforcing fibers bundled together with a sizing agent or the like
so as not to be unraveled. In such a case, because the base
material (matrix) resin is a thermoplastic resin, it is preferable
that a sizing agent taking into consideration the adhesiveness to
the base material resin be used as the sizing agent for bundling
reinforcing fiber tows. Because of the effect of the sizing agent
deposited on the reinforcing fibers, the reinforcing fibers are
prevented from being unraveled, being oriented randomly, and being
frayed. At the same time, the reinforcing fibers are allowed to
move and be shifted from each other. Thus, a reinforcing-fiber
sheet material having excellent drapeability can be obtained.
[0110] Taking into consideration the adhesiveness between the
reinforcing fibers and the base material resin, reinforcing fiber
tows on which no or little amount of sizing agent is deposited may
be used, or reinforcing fiber tows, after the sizing agent
deposited thereon is removed, may be formed into a
reinforcing-fiber sheet material. Even in such cases, the
reinforcing fibers can be prevented from being unraveled by joining
the thermoplastic-resin sheet material and the reinforcing-fiber
sheet material. In particular, by spreading the reinforcing fiber
tows to reduce the number of reinforcing fibers arranged in the
thickness direction, the reinforcing fibers can be further
prevented from being unraveled.
[0111] The reinforcing-fiber sheet material 32 and the
thermoplastic-resin sheet material 42 shown in FIG. 5 are joined by
a method in which the thermoplastic-resin sheet material is
thermally adhered to the entirety or several portions of one or
both surfaces of the reinforcing-fiber sheet material or a method
in which the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material are bonded with a thinly spread
adhesive not affecting the mechanical properties or the like of a
finished molding. Although the surface layer portion of the
reinforcing-fiber sheet material may be slightly impregnated with
the thermoplastic-resin sheet material when the reinforcing-fiber
sheet material is thermally adhered to the thermoplastic-resin
sheet material, even in such a case, the sheets exhibit sufficient
drapeability and are in a joined state.
[0112] FIG. 6 is a schematic view showing a part of another
thermoplastic-resin-reinforced sheet material 22 according to an
embodiment of the present invention. The
thermoplastic-resin-reinforced sheet material 22 has a
configuration in which the thermoplastic-resin sheet material 42 is
joined to a surface of the sheet-like reinforcing-fiber sheet
material 32 formed of a plurality of reinforcing fiber tows 32t,
each consisting of a plurality of reinforcing fibers 32f bundled
together with a sizing agent or the like, arranged in the width
direction, with the bonding thermoplastic-resin material 52 melted
or softened at a temperature lower than the melting temperature of
the thermoplastic-resin sheet material 42. The thermoplastic-resin
sheet material 42 may be joined to each surface of the
reinforcing-fiber sheet material 32. Furthermore, the
reinforcing-fiber sheet material 32 may be joined to each surface
of the thermoplastic-resin sheet material 42.
[0113] In FIG. 6, by bonding the reinforcing-fiber sheet material
32 and the thermoplastic-resin sheet material 42 with the bonding
thermoplastic-resin material 52 so as not to come apart, the
reinforcing-fiber sheet material 32 and the thermoplastic-resin
sheet material 42 are joined. That is, because the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material are joined without being heated to the melting temperature
of the thermoplastic-resin sheet material, the shape of the
reinforcing-fiber sheet material and the shape of the
thermoplastic-resin sheet material are maintained. Accordingly, the
resulting sheet material has excellent drapeability of the
thermoplastic-resin-reinforced sheet material and has excellent
straightness and distribution of the reinforcing fibers.
[0114] The thermoplastic-resin-reinforced sheet material 22 shown
in FIG. 7 is formed of a plurality of narrow
thermoplastic-resin-reinforced sheet materials 22H arranged in a
width direction in a sheet-like structure. The narrow
thermoplastic-resin-reinforced sheet materials 22H are each formed
by joining the narrow thermoplastic-resin sheet material 42 to a
surface of the narrow reinforcing-fiber sheet material 32,
consisting of a plurality of reinforcing fibers 32f, with the
bonding thermoplastic-resin material 52 melted or softened at a
temperature lower than the melting temperature of the
thermoplastic-resin sheet material 42. By arranging the plurality
of narrow thermoplastic-resin-reinforced sheet materials 22H in the
width direction and the thickness direction in this manner, the
unidirectionally reinforced thermoplastic-resin-reinforced sheet
material 22 is obtained. Furthermore, by weaving the narrow
thermoplastic-resin-reinforced sheet materials 22H, a
thermoplastic-resin-reinforced sheet material reinforced
bidirectionally, for example, in 0.degree. direction and 90.degree.
direction, can be obtained.
[0115] Also in each narrow thermoplastic-resin-reinforced sheet
material 22H shown in FIG. 7, the narrow thermoplastic-resin sheet
material 42 is joined to a surface of the narrow reinforcing-fiber
sheet material 32 with the bonding thermoplastic-resin material 52.
However, the narrow thermoplastic-resin sheet material may be
joined to each surface of the narrow reinforcing-fiber sheet
material with the bonding thermoplastic-resin material.
Furthermore, the narrow reinforcing-fiber sheet material may be
joined to each surface of the narrow thermoplastic-resin sheet
material with the bonding thermoplastic-resin material.
[0116] Although FIGS. 6 and 7 are the drawings in which no bonding
thermoplastic-resin material is deposited on the surface of the
thermoplastic-resin-reinforced sheet material 22, the bonding
thermoplastic-resin material may be dispersed and deposited on one
or both surfaces of the thermoplastic-resin-reinforced sheet
material 22.
[0117] In the thermoplastic-resin-reinforced sheet material, it is
possible to differentiate the amount of deposition per unit area of
the bonding thermoplastic-resin material for bonding the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material and the amount of deposition per unit area of the bonding
thermoplastic-resin material deposited on one or both surfaces of
the thermoplastic-resin-reinforced sheet material. Also it is
possible to differentiate the bonding thermoplastic-resin material
for bonding the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material and the bonding
thermoplastic-resin material deposited on one or both surfaces of
the thermoplastic-resin-reinforced sheet material.
[0118] By setting the amount of deposition per unit area of the
bonding thermoplastic-resin material for bonding the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material larger than the amount of deposition per unit area of the
bonding thermoplastic-resin material deposited on one or both
surfaces of the thermoplastic-resin-reinforced sheet material, or
by selecting a bonding thermoplastic-resin material having a
greater adhesiveness than the bonding thermoplastic-resin material
deposited on one or both surfaces of the
thermoplastic-resin-reinforced sheet material as a bonding
thermoplastic-resin material for bonding the reinforcing-fiber
sheet material and the thermoplastic-resin sheet material, a
multilayer thermoplastic-resin-reinforced sheet material having
greater adhesiveness between the reinforcing-fiber sheet material
and the thermoplastic-resin sheet material layer than between the
thermoplastic-resin-reinforced sheet materials can be obtained.
[0119] This allows the layers of the thermoplastic-resin-reinforced
sheet material to be shifted from each other while the
reinforcing-fiber sheet material is joined to the
thermoplastic-resin sheet material. That is, the multilayer
thermoplastic-resin-reinforced sheet material is formed of a
plurality of thermoplastic-resin-reinforced sheet materials bonded
together and is easy to handle. At the same time, the multilayer
thermoplastic-resin-reinforced sheet material can, when placed in
the shaping molds for forming, conform to the shape of the molds at
curved portions by locally breaking the adhesion between the layers
of the thermoplastic-resin-reinforced sheet material and by
shifting the layers of the thermoplastic-resin-reinforced sheet
material from each other without loosing the arranged state and
distribution state of the reinforcing fibers, and has more
excellent drapeability. This enables to obtain a high-quality
complex-shaped laminated molding.
[0120] Herein, the term "adhesiveness" refers to the strength with
which the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material, the reinforcing-fiber sheet
material and the reinforcing-fiber sheet material, and the
thermoplastic-resin sheet material and the thermoplastic-resin
sheet material are bonded together with the bonding
thermoplastic-resin material, and the phrase "great adhesiveness"
refers to "great bonding strength". The phrase "the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material are joined" refers to a state in which the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material are not separated or do not come apart during normal
handling, for example, conveying, lifting, or cutting the sheet
material.
[0121] The thickness or weight of the thermoplastic-resin sheet
material 42 to be joined to the reinforcing-fiber sheet material 32
is determined according to the weight (fiber weight per unit area)
of the reinforcing-fiber sheet material, the fiber volume content
when finished as a molding, and the like.
[0122] The reinforcing-fiber sheet material 32 is formed of, for
example, the plurality of reinforcing fiber tows 32t arranged in a
sheet-like structure, each consisting of the plurality of
reinforcing fibers 32f bundled together with a sizing agent or the
like so as not to be unraveled. Examples of the reinforcing fibers
32f include high-strength, high-modulus inorganic fibers used for
FRPs, such as carbon fiber, glass fiber, ceramic fiber, aramid
fiber, poly para-phenylene benzobisoxazole (PBO) fiber, and metal
fiber, or organic fibers. Fiber tows of the aforementioned fibers
may be used in combination. The fineness is not specified.
Similarly to the above-described reinforcing-fiber sheet materials
31, by setting the thickness of the reinforcing-fiber sheet
material 32 within ten times the diameter of the reinforcing fibers
32f, when a molding is formed, the distance over which the
thermoplastic-resin sheet material flows between the reinforcing
fibers for impregnation is further reduced. Because the reason and
method therefor are the same as those in the case of the
reinforcing-fiber sheet materials 31, an explanation thereof will
be omitted.
[0123] The thermoplastic-resin sheet material 42 serves as the base
material (matrix) resin and is composed of the same resin material
as the above-described thermoplastic-resin sheet materials 41.
[0124] The bonding thermoplastic-resin material 52 serves to bond
and integrate the reinforcing-fiber sheet material 32 and the
thermoplastic-resin sheet material 42. The bonding
thermoplastic-resin material 52 is composed of a thermoplastic
resin that is melted or softened at a temperature lower than the
melting temperature of the thermoplastic-resin sheet material to be
formed and that is capable of bonding the reinforcing-fiber sheet
material and the thermoplastic-resin sheet material, and a release
sheet material and the reinforcing-fiber sheet material or the
thermoplastic-resin sheet material. The bonding thermoplastic-resin
material 52 is deposited on one or both surfaces of at least one of
the reinforcing-fiber sheet material 32 and the thermoplastic-resin
sheet material 42. Preferably, the thermoplastic resin material 52
is deposited on one or both surfaces of at least one of the
reinforcing-fiber sheet material 32 and the thermoplastic-resin
sheet material 42 and is uniformly distributed. This achieves
secure bonding between the reinforcing-fiber sheet material 32 and
the thermoplastic-resin sheet material 42. Thus, the
thermoplastic-resin sheet material is joined to the
reinforcing-fiber sheet material, or a plurality of
thermoplastic-resin-reinforced sheet materials are stacked and
bonded together.
[0125] The bonding thermoplastic-resin material 52 may be either in
a powder form or a fibrous form. In the case of a fibrous form, it
can be used in the forms of dispersed filaments or staples, or
fabric such as wovens, knits, or nonwovens.
[0126] Furthermore, a resin with its melting point in the range
from 80 to 250.degree. is preferable as the bonding
thermoplastic-resin material 52. For example, polyamide,
copolymerized polyamide, polyurethane, or the like is selected. In
particular, copolymerized polyamide is preferable as the bonding
thermoplastic-resin material because of its low melting point and
excellent adhesiveness to the thermoplastic-resin sheet material
serving as the base material. In addition, it is desirable that a
bonding thermoplastic-resin material having good compatibility with
the thermoplastic-resin sheet material to be formed be selected.
This allows the bonding thermoplastic-resin material to be present
in a conformable manner in the thermoplastic resin material serving
as the base material when the bonding thermoplastic-resin material
melts into the thermoplastic resin material serving as the base
material.
[0127] It is preferable that the amount of deposition per unit area
of the bonding thermoplastic-resin material 52 be set within 3% of
the weight per unit area of the reinforcing-fiber sheet material,
and it is more preferable that it be set in the range from 0.5 to
2%. By reducing the amount of the bonding thermoplastic-resin
material 52 to be used, the influence of the bonding
thermoplastic-resin material on the mechanical properties and the
thermal properties of the resulting composite-material molding can
be minimized.
[0128] It is desirable that the bonding thermoplastic-resin
material 52 be distributed on one or both surfaces of at least one
of the reinforcing-fiber sheet material 32 and the
thermoplastic-resin sheet material 42, and it is more desirable
that it be uniformly distributed on the surface. This enables the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material to be securely bonded, i.e., joined, even if the bonding
thermoplastic-resin material is 3% or less, more preferably, in the
range from 0.5 to 2%. Because of the reinforcing-fiber sheet
material joined to the thermoplastic-resin sheet material, the
shape of the fiber tows constituting the reinforcing-fiber sheet
material, that is, the straightness and uniform distribution of the
reinforcing fibers can be maintained, and the shape of the
thermoplastic-resin sheet material as a sheet can be maintained.
Thus, the sheet material is easy to handle.
[0129] From FIGS. 5 to 7, although not shown therein, a release
sheet material can be bonded to the thermoplastic-resin-reinforced
sheet material with the bonding thermoplastic-resin material 52. In
particular, by bonding the release sheet material to the
thermoplastic-resin-reinforced sheet material, on the
reinforcing-fiber sheet material side, the shape of the
reinforcing-fiber sheet material can be maintained and the
straightness and uniform distribution of the reinforcing fibers
constituting the reinforcing-fiber sheet material can be more
stably maintained. Furthermore, when the
thermoplastic-resin-reinforced sheet material is to be cut, by
cutting it together with the release sheet material integrated
thereto, the thermoplastic-resin-reinforced sheet material can be
cut while random orientation of the fibers constituting the
reinforcing-fiber sheet material is further suppressed. Thus,
bonding and stacking of the thermoplastic-resin-reinforced sheet
materials after being cut can be performed while scattering of the
reinforcing fibers at the cut sections is minimized. Thus, a
high-quality composite-material molding can be obtained. As the
release sheet material, a release film such as a polyolefin resin
sheet, a thermosetting polyimide resin sheet, or a fluororesin
sheet, or release paper may be selected.
[0130] FIG. 8 is a schematic view showing a part of another
multilayer thermoplastic-resin-reinforced sheet material 12
according to an embodiment of the present invention. The multilayer
thermoplastic-resin-reinforced sheet material 12 is formed of four
thermoplastic-resin-reinforced sheet materials 22A to 22D, shown in
FIG. 5 or 6, stacked and bonded together with a bonding
thermoplastic-resin material. In FIG. 8, the
thermoplastic-resin-reinforced sheet materials 22A to 22D are
stacked such that the reinforcing fibers in the
thermoplastic-resin-reinforced sheet materials are oriented in
different axial directions.
[0131] FIG. 9 is an explanatory diagram related to a production
process of the thermoplastic-resin-reinforced sheet material. It is
an explanatory diagram related to a process of producing the
thermoplastic-resin-reinforced sheet material 21, in which the
thermoplastic-resin sheet material 41 is attached and thermally
adhered to a surface of the reinforcing-fiber sheet material 31
formed of reinforcing fiber multi-filament spread threads S1
arranged in the width direction, each consisting of the spread
reinforcing fiber tows 31t. FIG. 9A is a plan view and FIG. 9B is a
front view.
[0132] A thermoplastic-resin-reinforced sheet material producing
apparatus 200 shown in FIG. 9 consists of a multiple-fiber-tow
feeding mechanism 201, a multiple-fiber-tow spreading mechanism
202, a longitudinal-vibration applying mechanism 203, a
width-direction-vibration applying mechanism 204, a heating
mechanism 205, a cooling mechanism 206, a release film feeding
mechanism 207, a release film take-up mechanism 208, and a sheet
material take-up mechanism 209.
[0133] The multiple-fiber-tow feeding mechanism 201 includes a
plurality of reinforcing-fiber-tow bobbins 31b wound with the
reinforcing fiber tows 31t and allows the reinforcing fiber tows
31t to be fed at a substantially constant tension.
[0134] The fed reinforcing fiber tows 31t are spread into a wide
and thin form by the multiple-fiber-tow spreading mechanism 202.
This spreading mechanism employs a pneumatic tow-spreading method,
in which a fluid (in FIG. 9, sucked air flow) flowing in one
direction is allowed to act on the fiber tows using a wind-tunnel
tube, i.e., a known method disclosed in Patent Document 9. Any
spreading method for spreading the reinforcing fiber tows 31t may
be employed.
[0135] In the wind-tunnel tube, a plurality of rolls are disposed a
predetermined distance apart, and the reinforcing fiber tows 31t
run while being in contact with the upper portion, the lower
portion, the upper portion, the lower portion, . . . , and the
upper portion of these rolls. Because the longitudinal-vibration
applying mechanism 203 alternately tautens and slackens the
reinforcing fiber tows 31t, when the reinforcing fiber tows 31t are
slackened in the wind-tunnel tube, the reinforcing fiber tows 31t
are instantaneously bent in the direction in which the air flows at
the lower portion of the rolls, and the fibers are moved in the
width direction and spread. Then, because the reinforcing fiber
tows 31t, when tautened, run in a spread state while being in
contact with the lower portions of the rolls, the fibers are
straightened while the spread width is maintained. The reinforcing
fiber tows 31t run while repeating these states and become the
reinforcing fiber multi-filament spread threads S1 right after the
wind-tunnel tube.
[0136] The plurality of reinforcing fiber multi-filament spread
threads S1 arranged in the width direction are vibrated in the
width direction by the width-direction-vibration applying mechanism
204 and formed into a multi-filament spread sheet having no gaps
between the reinforcing fiber multi-filament spread threads S1,
i.e., the wide and thin reinforcing-fiber sheet material 31 in
which the reinforcing fibers are distributed.
[0137] After the thermoplastic-resin sheet material 41 is attached
to a surface of the reinforcing-fiber sheet material 31, the
reinforcing-fiber sheet material 31 is allowed to run through the
heating mechanism 205 and the cooling mechanism 206. Thus, the
thermoplastic-resin-reinforced sheet material 21, formed of the
reinforcing-fiber sheet material 31 and the thermoplastic-resin
sheet material 41 joined to a surface thereof, is obtained and
taken up on a thermoplastic-resin-reinforced sheet material reel
21b by the sheet material take-up mechanism 209. In FIG. 9, a
curved heating plate is used as the heating mechanism 205. By
allowing the reinforcing-fiber sheet material 31 to run over the
curved surface, continuous application of heat to the reinforcing
fibers is possible and the straightness of the fibers can be
increased.
[0138] In this mechanism, by attaching the thermoplastic-resin
sheet material to the reinforcing-fiber sheet material and applying
heat thereto, the thermoplastic-resin sheet material is melted and
thermally adhered, i.e., joined, to the reinforcing-fiber sheet
material. Although the surface layer portion of the
reinforcing-fiber sheet material may be impregnated with the
thermoplastic-resin sheet material depending on the heating
conditions and the like, the amount thereof is negligible, and the
drapeability of the thermoplastic-resin-reinforced sheet material
can be sufficiently obtained. Because the purpose is not to
impregnate the reinforcing-fiber sheet material with the
thermoplastic-resin sheet material, the processing speed can be set
to high and the pressing force need not be set to high. That is,
the thermoplastic-resin-reinforced sheet material can be produced
efficiently.
[0139] Although the thermoplastic-resin sheet material 41 is
attached to a surface of the reinforcing-fiber sheet material 31
from above in FIG. 9, the thermoplastic-resin sheet material 41 may
be attached from below, and it may also be attached to each surface
of the reinforcing-fiber sheet material 31 from above and below.
Furthermore, it is also possible that the reinforcing-fiber sheet
material 31 is attached to each surface of the thermoplastic-resin
sheet material 41, using another set of the mechanisms 201 to 204
disposed opposite the heating mechanism 205.
[0140] By placing release films 61 fed from the release film
feeding mechanism 207 on both surfaces of the base fabric formed of
the reinforcing-fiber sheet material 31 and the thermoplastic-resin
sheet material 41 that are joined together, the thermoplastic-resin
sheet material 41 melted on the heating mechanism 205 is prevented
from being adhered to the apparatus, and at the same time, the base
fabric is allowed to run without being damaged. The release films
61, after running through the cooling mechanism 206, are removed
from the thermoplastic-resin-reinforced sheet material 21 serving
as the base fabric and are taken up by the release film take-up
mechanism 208.
[0141] A sheet-like material, such as a thermoplastic resin film or
a thermoplastic-resin nonwoven fabric, may be used as the
thermoplastic-resin sheet material 41. It is also possible that an
extrusion mechanism is prepared, thermoplastic resin pellets are
mixed and melted by the extruder and extruded as a film using a
T-die or the like, and the film is directly attached to the
reinforcing-fiber sheet material 31. Furthermore, a sheet material
formed of thermoplastic resin fiber tows arranged in a width
direction in a sheet-like structure each consisting of a plurality
of thermoplastic resin fibers bundled together, a sheet material
formed of the thermoplastic resin fiber tows spread in a sheet-like
structure, or the like may also be used.
[0142] FIG. 10 is an explanatory diagram related to a production
process of a thermoplastic-resin-reinforced sheet material using
the above-described bonding thermoplastic-resin material. It is an
explanatory diagram related to a process of producing the
thermoplastic-resin-reinforced sheet material 22, in which the
thermoplastic-resin sheet material 42 is attached and thermally
adhered to a surface of the reinforcing-fiber sheet material 32
formed of reinforcing fiber multi-filament spread threads S2
arranged in the width direction, each consisting of the spread
reinforcing fiber tows 32t, and the bonding thermoplastic-resin
material 52 in a powder form is dispersed and thermally adhered to
the surface of the thermoplastic-resin sheet material 42. FIG. 10A
is a plan view and FIG. 10B is a front view.
[0143] A thermoplastic-resin-reinforced sheet material producing
apparatus 300 shown in FIG. 10 consists of a multiple-fiber-tow
feeding mechanism 301, a multiple-fiber-tow spreading mechanism
302, a longitudinal-vibration applying mechanism 303, a
width-direction-vibration applying mechanism 304, a heating
mechanism 305, a cooling mechanism 306, a thermoplastic-resin sheet
material feeding mechanism 307, a release sheet material feeding
mechanism 308, a release sheet material take-up mechanism 309, and
a reinforced sheet material take-up mechanism 310.
[0144] The multiple-fiber-tow feeding mechanism 301, the
multiple-fiber-tow spreading mechanism 302, the
longitudinal-vibration applying mechanism 303, and the
width-direction-vibration applying mechanism 304 may be similar to
the multiple-fiber-tow feeding mechanism 201, the
multiple-fiber-tow spreading mechanism 202, the
longitudinal-vibration applying mechanism 203 and the
width-direction-vibration applying mechanism 204. Accordingly, a
detailed explanation will be omitted. By employing these
mechanisms, the reinforcing fiber tows 32t can be efficiently
processed into the wide and thin reinforcing fiber multi-filament
spread threads S2 in which the constituent reinforcing fibers 32f
are distributed. In the case of untwisted carbon fiber tows, the
fiber tows can be spread to a width of about 2 to 7 times the width
thereof in a filament state, at a processing speed of 5 m/min. or
more, in such a manner that the reinforcing fibers are uniformly
distributed.
[0145] The wide and thin reinforcing-fiber sheet material 32, after
the thermoplastic-resin sheet material 42 is attached to a surface
of the reinforcing-fiber sheet material 32, is allowed to run over
the heating rolls 72 of the heating mechanism 305. Thus, the
thermoplastic-resin sheet material 42 is thermally adhered to a
surface of the reinforcing-fiber sheet material 32. The release
sheet material feeding mechanism 308 feeds the release sheet
material 62 between the reinforcing-fiber sheet material 32 and the
heating roll 72. On the heating roll 72 subsequent to a reverse
roll 73, the powdered bonding thermoplastic-resin material 52 is
dispersed onto the surface of the thermoplastic-resin sheet
material 42 joined to the reinforcing-fiber sheet material 32 with
the powder-dispersing apparatus 71, and the bonding
thermoplastic-resin material 52 is thermally adhered to the
thermoplastic-resin sheet material 42. Then, by being allowed to
run over cooling rolls 74 of the cooling mechanism 306, the
thermoplastic-resin sheet material 42 is joined to a surface of the
reinforcing-fiber sheet material 32, and the
thermoplastic-resin-reinforced sheet material 22, on the surface of
which the bonding thermoplastic-resin material 52 is deposited, is
obtained. The resulting thermoplastic-resin-reinforced sheet
material 22 is taken up on a thermoplastic-resin-reinforced sheet
material reel 22b by the reinforced sheet material take-up
mechanism 310. The release sheet material 62 is taken up by the
release sheet material take-up mechanism 309.
[0146] In this mechanism, by attaching the thermoplastic-resin
sheet material to the reinforcing-fiber sheet material and applying
heat thereto, the thermoplastic-resin sheet material is melted or
softened and thermally adhered, i.e., joined, to the
reinforcing-fiber sheet material. Although the surface layer
portion of the reinforcing-fiber sheet material may be impregnated
with the thermoplastic-resin sheet material depending on the
heating conditions and the like, the amount thereof is negligible,
and the drapeability of the thermoplastic-resin-reinforced sheet
material can be sufficiently obtained. Because the purpose is not
to impregnate the reinforcing-fiber sheet material with the
thermoplastic-resin sheet material, the processing speed can be set
to high and the pressing force need not be set to high. That is,
the thermoplastic-resin-reinforced sheet material can be produced
efficiently.
[0147] Although the thermoplastic-resin sheet material 42 is
attached to a surface of the reinforcing-fiber sheet material 32
from above in FIG. 10, the thermoplastic-resin sheet material 42
may be attached from below, and it may also be attached to each
surface of the reinforcing-fiber sheet material 32 from above and
below. Furthermore, it is also possible that the reinforcing-fiber
sheet material 32 is attached to each surface of the
thermoplastic-resin sheet material 42, using another set of the
mechanisms 301 to 304 disposed opposite the heating mechanism
305.
[0148] In FIG. 10, after the thermoplastic-resin sheet material is
joined to the reinforcing-fiber sheet material, on the subsequent
heating roll, a powdered bonding thermoplastic-resin material is
dispersed and thermally adhered to the surface of the
thermoplastic-resin sheet material. The temperature of the heating
roll can be set to lower than the melting temperature of the
thermoplastic-resin sheet material. Although only heating may be
performed because the purpose is thermal adhesion, hot pressing
using a pressing roll or the like may be performed, if necessary.
In addition, although the bonding thermoplastic-resin material is
dispersed only on a surface of the thermoplastic-resin sheet
material, the bonding thermoplastic-resin material may be dispersed
also on a surface of the reinforcing-fiber sheet material.
[0149] A sheet-like material, such as a thermoplastic resin film or
a thermoplastic-resin nonwoven fabric, may be used as the
thermoplastic-resin sheet material 42. It is also possible that an
extrusion mechanism is prepared, thermoplastic resin pellets or
powdered thermoplastic resin is mixed and melted by the extruder
and extruded as a film using a T-die or the like, and the film is
directly attached to the reinforcing-fiber sheet material 32.
Furthermore, a sheet material formed of thermoplastic resin fiber
tows arranged in a width direction in a sheet-like structure each
consisting of a plurality of thermoplastic resin fibers bundled
together, a sheet material formed of the thermoplastic resin fiber
tows spread in a sheet-like structure, or the like may be used.
[0150] In particular, because the thermoplastic resin film has a
smooth surface, it is easy to uniformly deposit the bonding
thermoplastic-resin material on the entire sheet surface of the
thermoplastic resin film. Accordingly, the reinforcing-fiber sheet
material and the thermoplastic resin film can be securely joined
even with a small amount of the bonding thermoplastic-resin
material.
[0151] The bonding thermoplastic-resin material 52 is deposited by
a method in which a fixed amount of the powdered bonding
thermoplastic-resin material is uniformly dispersed and deposited
on the surface of the reinforcing-fiber sheet material or
thermoplastic-resin sheet material using the powder-dispersing
apparatus 71, or a method in which the bonding thermoplastic-resin
material in the form of nonwoven fabric is attached and adhered to
the surface of the reinforcing-fiber sheet material or
thermoplastic-resin sheet material. It is also possible to use a
method in which the bonding thermoplastic-resin material is
dissolved in a solvent or the like to make a solution, the solution
is applied to the surface of the reinforcing-fiber sheet material
or thermoplastic-resin sheet material, and the solvent is vaporized
to allow the bonding thermoplastic-resin material to be deposited
on the surface of the reinforcing-fiber sheet material or
thermoplastic-resin sheet material. It is preferable that the
bonding thermoplastic-resin material 52 be uniformly deposited on
the sheet material, and the amount of deposition per unit area of
the bonding thermoplastic-resin material be within 3% of the weight
per unit area of the reinforcing-fiber sheet material.
[0152] FIG. 11 is an explanatory diagram related to another
production process of a thermoplastic-resin-reinforced sheet
material using the bonding thermoplastic-resin material. The
process in which the reinforcing fiber tows 32t are spread into the
reinforcing fiber multi-filament spread threads S2 and formed into
the reinforcing-fiber sheet material 32 is the same as that shown
in FIG. 10. It is an explanatory diagram related to a process of
producing the thermoplastic-resin-reinforced sheet material 22, in
which, after the aforementioned processes, the powdered bonding
thermoplastic-resin material 52 is dispersed on a surface of the
reinforcing-fiber sheet material 32, to which the
thermoplastic-resin sheet material 42 is attached and thermally
adhered. FIG. 11A is a plan view and FIG. 11B is a front view.
[0153] FIGS. 12 and 13 are each also an explanatory diagram related
to another production process of a thermoplastic-resin-reinforced
sheet material using the bonding thermoplastic-resin material. FIG.
12 is an explanatory diagram related to a process of producing the
thermoplastic-resin-reinforced sheet material 22, in which the
bonding thermoplastic-resin material 52 is dispersed on the
thermoplastic-resin sheet material 42, to which the
reinforcing-fiber sheet material 32 is attached and thermally
adhered. FIG. 13 is an explanatory diagram related to a process of
producing the thermoplastic-resin-reinforced sheet material 22, in
which the bonding thermoplastic-resin material 52 is dispersed and
thermally adhered to a surface of the thermoplastic-resin sheet
material 42 of the thermoplastic-resin-reinforced sheet material
obtained in FIG. 12. FIGS. 12 and 13 are front views.
[0154] In FIGS. 11, 12, and 13, the reinforcing-fiber sheet
material 32 and the thermoplastic-resin sheet material 42 are
joined with the bonding thermoplastic-resin material 52. At this
time, because the melting or softening temperature of the bonding
thermoplastic-resin material 52 capable of bonding the
reinforcing-fiber sheet material and the thermoplastic-resin sheet
material is lower than the melting temperature of the
thermoplastic-resin sheet material 42, the temperature of the
heating roll 72 can be set to a temperature lower than the melting
temperature of the thermoplastic-resin sheet material. This can
prevent or drastically reduce shrinkage of the thermoplastic-resin
sheet material possibly caused by heating. Thus, a high-quality
thermoplastic-resin-reinforced sheet material having no wavy fibers
or the like can be obtained.
[0155] In FIG. 13, the bonding thermoplastic-resin material 52 is
joined to each surface of the thermoplastic-resin sheet material.
In this case, the total amount of deposition per unit area of the
bonding thermoplastic-resin material deposited on both surfaces of
the thermoplastic-resin sheet material is preferably within 3% of
the weight per unit area of the reinforcing-fiber sheet material.
That is, the bonding thermoplastic-resin material is used such that
the total amount of deposition per unit area of the bonding
thermoplastic-resin material used in the
thermoplastic-resin-reinforced sheet material is within 3%, more
preferably, in the range from 0.5 to 2%, of the weight per unit
area of the reinforcing-fiber sheet material.
[0156] In addition, in FIG. 13, the amount of dispersion or resin
type of the bonding thermoplastic-resin material 52 dispersed on
the surface of the thermoplastic-resin sheet material 42 to allow
the reinforcing-fiber sheet material 32 and the thermoplastic-resin
sheet material 42 to be thermally adhered may be differentiated
from the amount of dispersion or resin type of the bonding
thermoplastic-resin material 52 dispersed on a surface of the
thermoplastic-resin-reinforced sheet material 22 in the subsequent
step.
[0157] From FIGS. 10 to 13, right after a plurality of reinforcing
fiber tows are spread into a multi-filament spread sheet, a
thermoplastic-resin sheet material is joined thereto in the same
line. Thus, the thermoplastic-resin sheet material can be joined
right after the distribution of the reinforcing fibers becomes
good.
[0158] From FIGS. 10 to 13, the plurality of cooling rolls 74
serving as the cooling mechanism 306 are provided. Although the
temperature of the cooling rolls 74 is lower than that of the
heating rolls 72, if rapid cooling is needed, air cooling, water
cooling, or the like may be performed. In contrast, if slow cooling
is needed, gradual cooling is performed by providing the plurality
of cooling rolls with a temperature gradient. Which of rapid
cooling and slow cooling is to be performed may be determined from
the shape of the thermoplastic-resin-reinforced sheet material to
be produced.
[0159] From FIGS. 10 to 13, when the melted or softened bonding
thermoplastic-resin material is adhered to the cooling roll, the
following method may be adopted: After the bonding
thermoplastic-resin material is dispersed, a release sheet material
is disposed also on the other surface so as to sandwich the
thermoplastic-resin-reinforced sheet material between the release
sheet materials. Then, the sheet is allowed to run, and after the
sheet is ejected from the cooling rolls, the release sheet
materials are taken up.
[0160] The bonding thermoplastic-resin material is melted or
softened by heating and cured by cooling. At this time, the bonding
thermoplastic-resin material shrinks and causes curling of the
reinforcing fibers, shrinkage of the thermoplastic-resin sheet
materials, etc., which may degrade the quality of the
thermoplastic-resin-reinforced sheet material. In such a case,
after the bonding thermoplastic-resin material is dispersed on the
thermoplastic-resin sheet material, heating and cooling are
performed while pressure is applied. For example, from FIGS. 10 to
13, by applying tension to the thermoplastic-resin-reinforced sheet
material and the release sheet material while the
thermoplastic-resin-reinforced sheet material runs over the heating
rolls and the cooling rolls, the thermoplastic-resin-reinforced
sheet material is pressed against the rolls. Thus, the
thermoplastic-resin-reinforced sheet material can run over the
heating rolls and the cooling rolls while being subjected to
continuous pressure. Furthermore, a pressing roll or the like for
applying pressure may be used.
[0161] From FIGS. 10 to 13, although not shown therein, the bonding
thermoplastic-resin material 52 may be dispersed on the surface of
the release sheet material 62. As a result, the
thermoplastic-resin-reinforced sheet material 22 and the release
sheet material 62 are bonded together. Then, the
thermoplastic-resin-reinforced sheet material 22 integrated with
the release sheet material 62 is taken up by the reinforced sheet
material take-up mechanism 310. In this case, the release sheet
material take-up mechanism 309 is not needed.
[0162] From FIGS. 11 to 13, application of heat or heat and
pressure is performed at a temperature lower than the temperature
at which the thermoplastic-resin sheet material 42 is melted, and
the thermoplastic-resin-reinforced sheet material 22 formed of the
reinforcing-fiber sheet material 32 and the thermoplastic-resin
sheet material 42 that are joined together with the bonding
thermoplastic-resin material 52 is produced. Because heating rolls
of low-temperature type may be used as the heating rolls 72,
relatively low-cost rolls can be introduced. In particular,
introduction of a wide heating roll also becomes easy.
[0163] Because the heating temperature is low, release paper or the
like can be used as the release sheet material 62. Although a
thermosetting polyimide resin sheet, a fluororesin sheet, or the
like can be used as the release sheet material 62, the cost of the
release sheet material increases. Thus, the use of release paper as
the release sheet material 62 enables low-cost production. In
addition, because the release paper is available in various widths
and lengths, a wide and long thermoplastic-resin-reinforced sheet
material 22 can be easily produced. Accordingly, it is possible to
produce a thermoplastic-resin-reinforced sheet material having a
width of 2 m or more.
[0164] In particular, when a heat-resistant thermoplastic-resin
sheet material composed of a heat-resistant thermoplastic resin,
such as PPS resin, PEI resin, or PEEK resin, is used as the
thermoplastic-resin sheet material 42, and in a method in which the
heat-resistant thermoplastic-resin sheet material is directly and
thermally adhered to the reinforcing-fiber sheet material, to allow
the reinforcing fibers and the thermoplastic resin to be thermally
adhered, the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material have to be heated to a
temperature at which the heat-resistant thermoplastic-resin sheet
material is melted or softened at the moment when they are joined.
Because such a temperature is high, equipment, release sheet
material, and the like for high-temperature use have to be used. On
the other hand, in a method in which the reinforcing-fiber sheet
material and the heat-resistant thermoplastic-resin sheet material
are joined with the bonding thermoplastic-resin material, the
heating temperature may be low. Thus, equipment, release sheet
material, and the like for low-temperature use can be used.
Accordingly, a thermoplastic-resin-reinforced sheet material
composed of a heat-resistant thermoplastic resin can be obtained
while the initial cost and the running cost is further reduced.
[0165] FIG. 14 is an explanatory diagram related to a production
process of a multilayer thermoplastic-resin-reinforced sheet
material. FIG. 14 is an explanatory diagram related to a process
for producing a multilayer thermoplastic-resin-reinforced sheet
material in which, four wide thermoplastic-resin-reinforced sheet
materials are sequentially stacked such that their
fiber-reinforcing directions are oriented in different directions
and are stitched with an integration thermoplastic-resin fiber
tow.
[0166] A sheet-type multilayer thermoplastic-resin-reinforced sheet
material producing apparatus 400 shown in FIG. 14 consists of an
a.degree. direction sheet material feeding mechanism 401, a
90.degree. direction sheet material feeding mechanism 402, a
-a.degree. direction sheet material feeding mechanism 403, a
0.degree. direction sheet material feeding mechanism 404, a
stitch-type integration mechanism 405, and a sheet material take-up
mechanism 406.
[0167] The sheet material feeding mechanisms 401 to 404 of the
respective directions are configured to draw the
thermoplastic-resin-reinforced sheet materials 21 from the
thermoplastic-resin-reinforced sheet material reels 21b and feed.
The mechanisms 401 to 403 draw the thermoplastic-resin-reinforced
sheet materials 21 in predetermined directions by a length equal to
or greater than the width of the multilayer
thermoplastic-resin-reinforced sheet material 11, cut them off from
the thermoplastic-resin-reinforced sheet material reels 21b with a
cutting mechanism (not shown), and attach them to running rails 81
at both ends that allow the multilayer
thermoplastic-resin-reinforced sheet material 11 to run. At this
time, by attaching such that the leading edge of a
thermoplastic-resin-reinforced sheet material to be attached abuts
on the trailing edge of the preceding
thermoplastic-resin-reinforced sheet material that is already
attached and running, a sheet that is fiber-reinforced in
predetermined directions and has no gaps or overlaps in the layers
of the multilayer thermoplastic-resin-reinforced sheet material can
be formed. Pins (not shown) or the like, to which the attached
thermoplastic-resin-reinforced sheet materials can be fixed, are
embedded in the running rails 81. The mechanism 404 has one or more
thermoplastic-resin-reinforced sheet material reels 21b (not shown)
such that a length equal to the width of the multilayer
thermoplastic-resin-reinforced sheet material 11 is obtained, and
continuously feeds the thermoplastic-resin-reinforced sheet
material 21 in the 0.degree. direction.
[0168] The mechanisms 401 and 403 feed the
thermoplastic-resin-reinforced sheet materials in the a-degree and
-a.degree. directions. At this time, although a.degree. can be set
in the range of 0.degree.<a.degree.<90.degree., it is
preferable that a.degree. be set in the range from 30 to
60.degree., from the standpoint of the size and ease of handling of
the apparatus. In addition, although the feeding directions,
feeding number, feeding order, etc., of the
thermoplastic-resin-reinforced sheet materials can be freely set,
they are preferably set according to the design of the molding. For
example, when a quasi-isotropy material is to be obtained, a
preferable stacking sequence of the thermoplastic-resin-reinforced
sheet materials is [45.degree./0.degree./-45.degree./90.degree.],
[45.degree./-45.degree./0.degree./90.degree.], or the like.
[0169] Then, the stacked thermoplastic-resin-reinforced sheet
materials 21 are stitched with the integration thermoplastic-resin
fiber tow 51 by the integration mechanism 405 by warp knitting or
the like. Thus, the multilayer thermoplastic-resin-reinforced sheet
material 11 having the layers stitched together is obtained. The
resulting multilayer thermoplastic-resin-reinforced sheet material
11 is taken up on the multilayer thermoplastic-resin-reinforced
sheet material reel 11b by the sheet material take-up mechanism
406.
[0170] At this time, stitching with the integration
thermoplastic-resin fiber tow 51 is performed at a certain interval
in the width direction of the multilayer
thermoplastic-resin-reinforced sheet material 11. A reduction in
the interval increases the amount of the integration
thermoplastic-resin fiber tow 51, which increases the amount of the
base material (matrix) and decreases the fiber volume content when
a finished molding is to be obtained. In contrast, an increase in
the interval makes it difficult to handle the multilayer
thermoplastic-resin-reinforced sheet material 11 as a sheet, which
makes it difficult to cut and stack the multilayer
thermoplastic-resin-reinforced sheet material 11. The stitching
interval of the integration thermoplastic-resin fiber tow 51 should
be determined according to the design of the molding.
[0171] FIG. 15 is an explanatory diagram related to a mechanism
used in the sheet material feeding mechanisms 401 to 403 shown in
FIG. 14, which feeds the narrow thermoplastic-resin-reinforced
sheet materials 21H arranged in the width direction while producing
them.
[0172] While the thermoplastic-resin-reinforced sheet material 21
is drawn from the thermoplastic-resin-reinforced sheet material
reel 21b wound with the wide thermoplastic-resin-reinforced sheet
material 21, the thermoplastic-resin-reinforced sheet material 21
is continuously cut in the sheet length direction, at a desired
interval in the width direction, with a plurality of cutter blades
82 arranged at a desired interval in the width direction of the
thermoplastic-resin-reinforced sheet material 21 and a cutter-blade
receiving roll 83. Thus, the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H are fed while
being produced. The width of the narrow
thermoplastic-resin-reinforced sheet materials is determined
according to the design of the resulting multilayer
thermoplastic-resin-reinforced sheet material. When an improvement
of the drapeability of the sheet is taken into consideration, a
smaller width is better. However, an excessively small width can
result in breakage of the narrow thermoplastic-resin-reinforced
sheet materials, and their continuity can be lost. Therefore, the
width is preferably in the range from 1 mm to 20 mm, and more
preferably, in the range from 2 mm to 10 mm.
[0173] By adopting this mechanism, the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H arranged in the
width direction can be efficiently fed. Although the cutter blades
82 may be either rotatable or fixed, a method in which the round
cutter blades 82 freely rotatable in response to running of the
thermoplastic-resin-reinforced sheet material 21 and the receiving
roll 83 below the cutter blades are provided, between which the
thermoplastic-resin-reinforced sheet material 21 is allowed to run
to be cut, is one of the methods for cutting the
thermoplastic-resin-reinforced sheet material 21 while preventing
the reinforcing fibers from being frayed. A method using a laser
may be employed to cut the wide thermoplastic-resin-reinforced
sheet material 21 at a desired interval in the width direction.
[0174] FIG. 16 is an explanatory diagram related to an apparatus
500 for producing the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H from the wide
thermoplastic-resin-reinforced sheet material 21 and for winding
the narrow thermoplastic-resin-reinforced sheet materials on the
bobbins or the like.
[0175] The narrow thermoplastic-resin-reinforced sheet material
producing apparatus 500 consists of a sheet material feeding
mechanism 501, a sheet material cutting mechanism 502, and a
narrow-sheet-material take-up mechanism 503. The sheet material
feeding mechanism 501 draws the wide thermoplastic-resin-reinforced
sheet material 21 from the thermoplastic-resin-reinforced sheet
material reel 21b at a constant tension. Then, the sheet material
cutting mechanism 502 continuously cuts the
thermoplastic-resin-reinforced sheet material 21 in the sheet
length direction, at a desired interval in the width direction.
Thus, the plurality of narrow thermoplastic-resin-reinforced sheet
materials 21H are produced. Take-over rolls 84 allow the resulting
narrow thermoplastic-resin-reinforced sheet materials 21H to run at
a constant speed. The sheet material cutting mechanism 502 is
substantially the same mechanism as the one shown in FIG. 15 and
consists of the plurality of cutter blades 82 arranged at a desired
interval in the width direction of the
thermoplastic-resin-reinforced sheet material 21 and the
cutter-blade receiving roll 83. The plurality of narrow
thermoplastic-resin-reinforced sheet materials discharged from the
take-over rolls 84 are taken up on respective bobbins 21Hb or the
like while being traversed, by the narrow-sheet-material take-up
mechanism 503. At this time, depending on the width, the narrow
thermoplastic-resin-reinforced sheet materials 21H may be wound in
a tape-like form without being traversed.
[0176] In FIGS. 15 and 16, a method for producing the plurality of
narrow thermoplastic-resin-reinforced sheet materials 21H by
continuously cutting the wide thermoplastic-resin-reinforced sheet
material 21 in the sheet length direction, at a desired interval in
the width direction, is shown. As another method, using the
apparatus shown in FIG. 9, a narrow thermoplastic-resin-reinforced
sheet material may be formed by joining a narrow
thermoplastic-resin-reinforced sheet material to a surface of a
narrow reinforcing-fiber sheet material, and the narrow
thermoplastic-resin-reinforced sheet material may be wound on the
bobbin or the like.
[0177] FIG. 17 is an explanatory diagram related to a process for
producing the multilayer thermoplastic-resin-reinforced sheet
material 11 in which, while the thermoplastic-resin-reinforced
sheet materials 21 are formed from the narrow
thermoplastic-resin-reinforced sheet materials 21H obtained in FIG.
16, four of them are sequentially stacked such that their
fiber-reinforcing directions are oriented in different directions
and stitched with the integration thermoplastic-resin fiber tow 51.
A narrow-sheet-type multilayer thermoplastic-resin-reinforced sheet
material producing apparatus 600 shown in FIG. 17 consists of an
a.degree. direction narrow-sheet-material feeding mechanism 601, a
90.degree. direction narrow-sheet-material feeding mechanism 602, a
-a.degree. direction narrow-sheet-material feeding mechanism 603, a
0.degree. direction narrow-sheet-material feeding mechanism 604, a
stitch-type integration mechanism 605, and a sheet material take-up
mechanism 606.
[0178] The narrow-sheet-material feeding mechanisms of the
respective directions in the mechanisms 601 to 604 draw the narrow
thermoplastic-resin-reinforced sheet materials 21H from the
plurality of narrow thermoplastic-resin-reinforced sheet material
bobbins 21Hb, arrange them in a sheet-like structure, and feed. The
mechanism 601 to 603 each arrange the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H in a sheet-like
structure, hook them on an edge of the running rails 81 at both
ends, which allow the multilayer thermoplastic-resin-reinforced
sheet material 11 to run, guide them toward the other edge, and
hook them on the other edge. By repeating this operation, the
thermoplastic-resin-reinforced sheet materials in the respective
layers are formed. At this time, the narrow
thermoplastic-resin-reinforced sheet materials 21H are continuous
without being cut, and the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H are arranged
with almost no gaps or overlaps in a sheet-like structure that is
fiber-reinforced in predetermined directions. Pins (not shown) or
the like are embedded in the running rails 81 so that the plurality
of narrow thermoplastic-resin-reinforced sheet materials can be
hooked and fixed. The mechanism 604 arranges the plurality of
narrow thermoplastic-resin-reinforced sheet materials in a
sheet-like structure such that a length equal to the width of the
multilayer thermoplastic-resin-reinforced sheet material 11 can be
provided, and continuously feeds the narrow
thermoplastic-resin-reinforced sheet materials arranged in a
sheet-like structure in the 0.degree. direction.
[0179] The mechanisms 601 and 603 feed the narrow
thermoplastic-resin-reinforced sheet materials in a-degree and
-a.degree. directions. Similarly to the sheet-type multilayer
thermoplastic-resin-reinforced sheet material producing apparatus
400 shown in FIG. 14, although a.degree. can be set in the range of
0.degree.<a.degree.<90.degree., it is preferable that it be
set in the range from 30 to 60.degree. from the standpoint of the
size and ease of handling of the apparatus. In addition, although
the feeding directions, feeding number, feeding order, etc., of the
narrow thermoplastic-resin-reinforced sheet materials to be fed can
be freely set, they are preferably set according to the design of
the molding.
[0180] Then, the thermoplastic-resin-reinforced sheet materials
each formed of the plurality of narrow
thermoplastic-resin-reinforced sheet materials 21H are stacked and
stitched with the integration thermoplastic-resin fiber tow 51 by
the stitch-type integration mechanism 605 by warp knitting or the
like. Thus, the multilayer thermoplastic-resin-reinforced sheet
material 11 having the layers stitched together is obtained. The
stitching interval of the integration thermoplastic-resin fiber tow
51 should be determined according to the design of the molding or
the like. The resulting multilayer thermoplastic-resin-reinforced
sheet material 11 is taken up by the sheet material take-up
mechanism 606 on the multilayer thermoplastic-resin-reinforced
sheet material reel 11b.
[0181] FIG. 18 is an explanatory diagram related to a
heat-integration mechanism 700 usable in stead of the stitch-type
integration mechanism in the apparatus shown in FIGS. 14 and
17.
[0182] The heat-integration mechanism 700 allows the
thermoplastic-resin-reinforced sheet materials, after being
stacked, to run with the release films 61 fitted to the top and
bottom surfaces thereof and applies heat or heat and pressure to
the stacked thermoplastic-resin-reinforced sheet materials with
heating rolls 85. Thus, the thermoplastic-resin sheet materials of
the respective layers are melted and thermally adhered to the
reinforcing-fiber sheet materials in upper and lower layers. After
the melted thermoplastic-resin sheet materials are cured by cooling
rolls 86 and the respective layers of the
thermoplastic-resin-reinforced sheet materials are bonded together,
the release films on the top and bottom surfaces are removed. Thus,
the multilayer thermoplastic-resin-reinforced sheet material 11 is
obtained. In FIG. 18, application of heat or heat and pressure at a
higher speed is enabled by using the two pairs of heating rolls
85.
[0183] FIG. 19 is an explanatory diagram related to the heating
rolls 85 used in the heat-integration mechanism 700 shown in FIG.
18. When a roll 85A having a flat roll surface as shown in FIG. 19A
is used as the heating roll 85, heat or heat and pressure can be
applied to the entire sheet surface of the stacked
thermoplastic-resin-reinforced sheet materials. When a roll 85B
having a patterned roll surface as shown in FIG. 19B is used, heat
or heat and pressure can be applied not to the entire sheet surface
of the stacked thermoplastic-resin-reinforced sheet materials, but
to parts thereof.
[0184] A multilayer thermoplastic-resin-reinforced sheet material
formed by partially applying heat or heat and pressure so as to
partially bond the stacked thermoplastic-resin-reinforced sheet
materials allows the layers of the thermoplastic-resin-reinforced
sheet materials to be slightly moved or shifted from each other.
Thus, the sheet material can have better drapeability.
[0185] Although a method using heating rolls as shown in FIG. 18
has been described as a method for applying heat or heat and
pressure to the stacked thermoplastic-resin-reinforced sheet
materials, another method is also possible. For example, a method
using hot press plates, a method employing a double press method
using metal belts, or the like may be used.
[0186] FIG. 20 is an explanatory diagram related to a production
process for obtaining a thermoplastic-resin multilayer reinforced
molding A from the multilayer thermoplastic-resin-reinforced sheet
material 11. The multilayer thermoplastic-resin-reinforced sheet
material 11 formed by the multilayer thermoplastic-resin-reinforced
sheet material producing apparatuses 400 and 600 is cut into pieces
having a desired size, at a desired angle. After
thermoplastic-resin-reinforced sheet materials L1 and L2, after
being cut, are stacked in a shaping lower metal mold 92 placed in a
hot press molding apparatus 90, a shaping upper metal mold 91 is
lowered and hot pressing is performed to allow the reinforcing
fibers to be impregnated with the thermoplastic-resin sheet
material, and, in the case of stitch-integration, with the
integration thermoplastic-resin fiber tow. After cooling, the
molded thermoplastic-resin multilayer reinforced molding A is taken
out of the shaping metal molds.
[0187] Although two thermoplastic-resin-reinforced sheet materials
L1 and L2 are cut out from the thermoplastic-resin-reinforced sheet
material 11 in FIG. 20, the number of them is not limited to two.
Depending on the design, a necessary number of sheet materials is
cut out and stacked. Furthermore, it is desirable that the cutting
angle be changed if necessary. When stacked, they may be placed
upside-down in the metal molds, if necessary.
[0188] Because the resulting thermoplastic-resin multilayer
reinforced molding A has aggregated fibers and the
thermoplastic-resin sheet material in each layer, the reinforcing
fiber tows are thoroughly impregnated with the thermoplastic resin,
and the resulting molding has few voids (gaps). Furthermore,
because the impregnation distance of the thermoplastic resin is
reduced, the molding has excellent straightness and distribution of
the reinforcing fibers, as well as excellent surface
smoothness.
[0189] Another production process for obtaining the
thermoplastic-resin multilayer reinforced molding will be described
below. In FIG. 21, the multilayer thermoplastic-resin-reinforced
sheet material 11 formed by the multilayer
thermoplastic-resin-reinforced sheet material producing apparatuses
400 and 600 is cut into pieces having a desired size, at a desired
angle, and the thermoplastic-resin-reinforced sheet materials L1
and L2, after being cut, are stacked on a flat lower metal mold 94,
serving as a preforming lower mold, placed in the hot press molding
apparatus 90. Then, a flat upper metal mold 93, serving as a
preforming upper mold, is lowered, and hot pressing is performed to
allow the reinforcing fibers to be impregnated with the
thermoplastic-resin sheet material, and, in the case of
stitch-integration, with the integration thermoplastic-resin fiber
tow. After cooling, a preformed laminate B is taken out. Because
the preforming molds are flat, the preformed laminate B is a flat
laminate. Then, the preformed laminate B is heated by a heating
unit 95 employing a heating method such as a far-infrared method or
the like until the thermoplastic resin serving as the base material
(matrix) is softened and melted. Thereafter, the preformed laminate
B in that state is placed in the shaping lower metal mold 92
provided in a cold press molding apparatus 96. Then, the shaping
upper metal mold 91 is immediately lowered and pressing is
performed to form the preformed laminate B into a desired shape.
Thus, the thermoplastic-resin multilayer reinforced molding A is
obtained.
[0190] Because a preformed laminate is formed of the multilayer
thermoplastic-resin-reinforced sheet material, the laminate has
excellent straightness and distribution of the reinforcing fibers,
as well as excellent surface smoothness, and has few voids.
Furthermore, because a molding is formed from the preformed
laminate, the resulting thermoplastic-resin multilayer reinforced
molding is a high-quality molding having excellent straightness and
distribution of the reinforcing fibers, as well as excellent
surface smoothness, and having few voids. Making preforming molds
have a flat shape to form a plate-shaped preformed laminate is
preferable because there are advantages in that fabrication of the
metal molds is easy, short-time forming is easy, and high-quality
laminates can be easily produced.
[0191] Although it is thought that the molding time is required
because press molding is performed twice, there are advantages in
that the production of a plate-shaped laminate or the like, as a
preformed laminate, is easy, and the processing time of a molding
can be reduced because, when the preformed laminate is formed into
a molding, the shaping metal molds can be maintained at a constant
temperature (cooled state) and alternate heating and cooling of the
shaping metal molds is not necessary. Accordingly, the resulting
thermoplastic-resin multilayer reinforced molding is a low-cost
molding.
[0192] Next, an embodiment related to a method for forming a
thermoplastic-resin composite-material molding of the present
invention will be described. FIG. 22 is a cross-sectional view
showing a state in which a molding material 1, which is a
multilayer thermoplastic-resin-reinforced sheet material, is
disposed between a pair of shaping molds, 100 and 101. The shaping
molds 100 and 101 are formed by processing thin plates having the
same thickness, and in this example, stepped portions 100a and 101a
are formed such that the shaping molds 100 and 101 are recessed
downward in the middle. A material that exhibits little thermal
deformation during heating and cooling and has excellent thermal
conductivity is preferable for the material of the shaping molds
100 and 101. Although examples of such a material include a metal
material, such as iron, and a carbon fiber carbon composite
material, referred to as a "CC composite", the carbon fiber carbon
composite material is particularly preferable.
[0193] Although thin plates are used as the shaping molds in this
example, as long as contact portions, with which the molding
material 1 is in contact, are formed to have a uniform thickness,
the thicknesses of portions other than the contact portions may be
different. In addition, the contact portions of the shaping molds
with respect to the molding material are formed to have a uniform
thickness so as to obtain uniform thermal conductivity. By reducing
the thickness, the thermal conductivity can be increased.
[0194] In the molding material 1, a thermoplastic resin material is
unevenly distributed between layers consisting of reinforcing fiber
materials. In this example, the molding material 1 is formed by
stacking a plurality of thermoplastic-resin-reinforced sheet
materials 2 each formed of a reinforcing-fiber sheet material 3 and
a thermoplastic-resin sheet material 4. The molding material 1 has
excellent drapeability and is disposed such that the layer
direction thereof extends along the mold surfaces of the shaping
molds 100 and 101. A gas-discharging space 102 is formed around the
molding material 1, between peripheral portions 100b and 101b of
the shaping molds 100 and 101, and the peripheral portion of the
molding material 1 is open without being closed.
[0195] As a molding material used in the present invention, a
molding material in which a thermoplastic resin material serving as
a matrix is unevenly distributed between layers formed of arranged
reinforcing fiber materials is preferable, and in addition to the
above-described multilayer thermoplastic-resin-reinforced sheet
material, a molding material in which a thermoplastic resin
material in powder or staple form is distributed between layers
formed of arranged reinforcing fiber materials or a molding
material in which a thermoplastic resin material in nonwoven fabric
or fabric form is disposed between the layers can be used.
Furthermore, a prepreg sheet formed of a reinforcing fiber material
impregnated with a thermoplastic resin material may be used as a
molding material.
[0196] The shaping molds 100 and 101 holding the molding material 1
therebetween are arranged so as to clamp the molding material 1 at
a predetermined distance with a fastening member (not shown). If
the molding material 1 can be held in a stable clamped state at a
predetermined distance by the weight of the shaping mold 101, the
fastening member does not need to be used.
[0197] To improve the releasability of a shaped molding, it is
preferable that a release treatment, i.e., application of a known
release agent, be performed on the surfaces of the shaping molds
100 and 101 to be in contact with the molding material 1.
Alternatively, to improve the releasability, a release sheet
material may be provided at portions of the molding material to be
in contact with the shaping molds. As the release sheet material, a
release film such as a polyolefin resin sheet, a thermosetting
polyimide resin sheet, or a fluororesin sheet, or release paper may
be selected.
[0198] FIG. 23 is an explanatory diagram showing a process of
forming the molding material 1 placed between the shaping molds 100
and 101. First, as described with reference to FIG. 22, the molding
material 1 is placed and clamped at a predetermined distance
between the shaping molds 100 and 101 (FIG. 23A).
[0199] Next, the shaping molds 100 and 101, holding the molding
material 1 therebetween, is set in a hot press 103 (FIG. 23B). Hot
press molds 104 and 105 have mold surfaces formed in the same shape
as the shaping molds 100 and 101. The lower hot press mold 104 has
in its mold surface a stepped portion formed to fit the contact
surface of the shaping mold 100. Similarly, the upper hot press
mold 105 has in its mold surface a stepped portion formed to fit
the contact surface of the shaping mold 101.
[0200] The hot press molds 104 and 105 are preliminarily heated to
a predetermined heating temperature by a built-in heater and clamp
the shaping molds 100 and 101 placed between the hot press molds
104 and 105 from both sides in the top-bottom direction to perform
hot pressing. The heating temperature and the pressing pressure may
be adequately set according to the material of the molding
material.
[0201] During application of heat and pressure by the hot press
molds, because the hot press molds and the shaping molds are in
close contact, thermal conductivity is excellent, and because the
shaping molds are formed to have a uniform thickness, the conducted
heat is substantially uniformly applied to the entire molding
material. Thus, the entire molding material is substantially
uniformly heated. As a result, the entire thermoplastic-resin sheet
material 4 arranged substantially parallel to the contact surfaces
of the shaping molds is substantially simultaneously heated and
melted, and then impregnated into the entire reinforcing-fiber
sheet materials 3 on both sides thereof.
[0202] When the reinforcing-fiber sheet materials 3 are gradually
impregnated with the thermoplastic resin material from both sides,
the internal air flows and is discharged into the gas-discharging
space 102 through the peripheral portion of the molding material 1.
Thus, impregnation of the thermoplastic resin material is performed
while the internal air of the reinforcing-fiber sheet materials 3
is efficiently discharged without remaining in the inside.
[0203] After the hot pressing, the shaping molds 100 and 101 are
taken out of the hot press and set in a cold press 106 (FIG. 23C).
Mold surfaces of cold press molds 107 and 108 are formed in the
same shape as the shaping molds 100 and 101. The lower cold press
mold 107 has in its mold surface a stepped portion formed to fit
the contact surface of the shaping mold 100. Similarly, the upper
hot press mold 108 has in its mold surface a stepped portion formed
to fit the contact surface of the shaping mold 101.
[0204] The cold press molds 107 and 108 are preliminarily set to a
predetermined cooling temperature (for example, a normal
temperature state) by a cooling unit (not shown) and clamp the
shaping molds 100 and 101 placed between the cold press molds 107
and 108 from both sides in the top-bottom direction to perform cold
pressing. The cooling temperature and the pressing pressure may be
adequately set according to the material of the molding
material.
[0205] By performing cooling while applying pressure with the cold
press molds, the thermoplastic resin material melted and
impregnated inside the molding material 1 is cured while being
subjected to pressure. At this time, as described above, because
the thickness of the shaping molds 100 and 101 is set to be
uniform, the thermal conductivity of the entire molding material 1
is substantially uniform, and the entire molding material 1 is
substantially uniformly cooled. Therefore, the thermoplastic resin
material is evenly cooled and cured, and the molding A having no
warpage can be obtained (FIG. 23D).
[0206] FIG. 24 is an explanatory diagram of a process related to
another embodiment for forming the molding material 1 using the
shaping molds 100 and 101. In this example, a ring-shaped seal
member 110 is disposed at the entire peripheral portion of the
shaping mold 100. A tube 109 connected to an air suction unit (not
shown) communicates with the shaping mold 101.
[0207] First, the molding material 1 is placed in the shaping mold
100, and the shaping mold 101 is placed on the molding material 1.
The shaping molds 100 and 101 are then fastened with a fastening
member (not shown) so as to clamp the molding material 1 (FIG.
24A). At this time, the seal member 110 is compressed by the
shaping molds, making the inside in an airtight state. The tube 109
is attached so as to communicate with the gas-discharging space 102
provided at the peripheral portions of the shaping molds 100 and
101. After the inside of the shaping molds is brought into an
airtight state by the seal member 110, the air suction unit is
activated to bring the inside into a vacuum or reduced pressure
state (FIG. 24B). In this case, the term "reduced pressure state"
refers to a pressure state close to vacuum, which is, for example,
a pressure state of 10 Torr or less.
[0208] Then, the shaping molds 100 and 101 in a vacuum or reduced
pressure state are placed in the hot press 103 similar to that in
the embodiment described with reference to FIG. 23, and are
subjected to hot pressing (FIG. 24C). The heating allows the
thermoplastic resin material in the molding material to be melted
and impregnated. Because the inside of the shaping molds is in a
vacuum or reduced pressure state, the melted thermoplastic resin
material is sucked and impregnation into the reinforcing-fiber
sheet material is accelerated. Thus, impregnation can be performed
in a short time, without allowing air to remain inside.
[0209] After the hot pressing, cold pressing is performed with the
cold press 106 similar to that in the embodiment described with
reference to FIG. 23 (FIG. 24D). The melted and impregnated
thermoplastic resin material is evenly cured through cooling,
whereby the molding A having no warpage can be formed (FIG.
24E).
[0210] As shown in FIGS. 25A and 25B, when the seal member 110 is
attached to the shaping molds, by forming groove portions 100c and
101c in the peripheral portions of the shaping molds 100 and 110
and by fitting the seal member 110 to the groove portions 100c and
101c to create an airtight state, an airtight structure can be more
assuredly achieved in the inside of the shaping molds.
[0211] FIG. 26 is an explanatory diagram of a process related to an
embodiment in which a plurality of molding materials are
simultaneously molded. In this example, four flat shaping molds 111
are used. Molding materials 1A, 1B, and 1C are disposed between the
shaping molds 111, and the shaping molds 111 are fastened with a
fastening member (not shown) so as to clamp the molding materials
at a predetermined distance (FIG. 26A).
[0212] Then, the shaping molds 111 are placed between hot press
molds 104' and 105' of the hot press 103 (FIG. 26B). The hot press
molds 104' and 105' have flat mold surfaces, and hot pressing is
performed such that they are in close contact with the shaping
molds 111. Because the thicknesses of the contact portions of the
shaping molds 111 with respect to the molding materials are all the
same, the thermal conductivity from the hot press molds 104' and
105' to the respective molding materials is substantially uniform.
Thus, the entire thermoplastic resin materials in the respective
molding materials are substantially simultaneously melted and
impregnated.
[0213] The shaping molds 111 after the hot pressing are then placed
between cold press molds 107' and 108' of the cold press 106 (FIG.
26C). The cold press molds 107' and 108' have flat mold surfaces,
and cold pressing is performed such that they are in close contact
with the shaping molds 111. The melted and impregnated
thermoplastic resin material is evenly cured and molded through
cold pressing, and the molding materials are each finished as a
molding B having no warpage.
[0214] Thus, the use of a plurality of shaping molds having the
same shape enables a plurality of molding materials to be formed
simultaneously and the production efficiency to be significantly
improved. Moreover, by fitting the seal member, as shown in FIG.
24, between the shaping molds to make the inside in a vacuum or
reduced pressure state, impregnation of the melted thermoplastic
resin material can be accelerated.
[0215] In the above-described embodiments, one hot press and one
cold press are used. However, a plurality of hot presses or cold
presses may be used to perform molding. In such a case, by
differentiating heating-temperatures of the hot presses and
performing hot pressing several times sequentially from low heating
temperatures to high heating temperatures, melting and impregnation
of the thermoplastic resin materials in the molding material can be
assuredly performed. In addition, by differentiating cooling
temperatures of the cold presses and performing cold pressing
several times sequentially from high cooling temperatures to low
cooling temperatures, the thermoplastic resin materials impregnated
into the molding material can be assuredly cured.
EXAMPLE
Example 1
[0216] Using the following materials, a multilayer
thermoplastic-resin-reinforced sheet material was produced.
<Materials Used>
(Fiber Tow Used as Reinforcing Fiber Tow)
[0217] TR50S-15K, fiber diameter: about 7 .mu.m, number of fibers:
15000, produced by MITSUBISHI RAYON CO., LTD.
(Resin Used as Thermoplastic-Resin Sheet Material)
[0218] Nylon 6 resin film, film thickness: 20 .mu.m, produced by
Mitsubishi Chemical Corporation
(Fiber Tow Used as Integration Thermoplastic-Resin Fiber Tow)
[0219] Nylon 6 multi-filaments, 77dtex-24filaments, produced by
Toray Industries, Inc.
<Production Process>
[0220] (1) Sixteen filaments of reinforcing fiber tow TR50S-15K
were set 20 mm apart. Using a method for simultaneously spreading
multiple filaments by air (refer to Patent Document 9), each
reinforcing fiber tow was spread to a width of 20 mm. (2) The
reinforcing fiber multi-filament spread threads, each spread to a
width of 20 mm, were vibrated in the width direction and formed
into a reinforcing-fiber sheet material having no gaps between the
reinforcing fiber multi-filament spread threads. The resulting
reinforcing-fiber sheet material had a width of 320 mm and a fiber
weight (fiber weight per unit area) of about 50 g/m.sup.2. (3) The
resulting reinforcing-fiber sheet material was continuously fed to
a heating mechanism by the production apparatus as shown in FIG. 9,
and joined to a thermoplastic-resin sheet material. At this time,
the temperature of the heating mechanism was controlled at about
270.degree.. A thermosetting polyimide resin film (product name:
UPILEX-S, thickness: 25 .mu.m, manufacturer: UBE INDUSTRIES, LTD.),
serving as a release film, was fed together with the
reinforcing-fiber sheet material. The
thermoplastic-resin-reinforced sheet material was joined to the
reinforcing-fiber sheet material at a speed of 10 m/min. (4) By
removing the release film from the base fabric discharged from a
cooling mechanism, a thermoplastic-resin-reinforced sheet material
formed of the reinforcing-fiber sheet material and the
thermoplastic-resin sheet material joined to a surface thereof was
obtained. (5) The resulting thermoplastic-resin-reinforced sheet
materials were stacked in 45.degree. direction, 0.degree.
direction, -45.degree. direction, and 90.degree. direction into a
laminate sheet having a width of 320 mm by the production apparatus
as shown in FIG. 14, and sewn with an integration
thermoplastic-resin fiber tow with a zigzag stitch in 0.degree.
direction at an interval of 20 mm. Thus, a multilayer
thermoplastic-resin-reinforced sheet material was obtained.
<Evaluation>
[0221] The resulting multilayer thermoplastic-resin-reinforced
sheet material was a multiaxially reinforced sheet material that
was fiber-reinforced in
[45.degree./0.degree./-45.degree./90.degree.] directions, in each
layer of which the reinforcing fibers were formed in a sheet-like
structure and the thermoplastic-resin sheet material was joined to
a surface thereof. In the respective thermoplastic-resin-reinforced
sheet materials, the reinforcing fibers were straight, uniformly
distributed, and arranged in one direction. The thermoplastic-resin
sheet material joined thereto prevented the reinforcing fibers from
bundling or being unraveled and frayed.
Example 2
[0222] A plurality of narrow thermoplastic-resin-reinforced sheet
materials were formed from the thermoplastic-resin-reinforced sheet
material obtained by going through (1) to (4) of Example 1. Then, a
multilayer thermoplastic-resin-reinforced sheet material was
produced.
<Materials Used>
[0223] The reinforcing fiber tow, the thermoplastic-resin sheet
material, and the integration thermoplastic-resin fiber tow were
the same as those used in Example 1.
<Production Process>
[0224] (1) A thermoplastic-resin-reinforced sheet material having a
width of 320 mm was formed by going through (1) to (4) of Example
1. (2) Using the production apparatus as shown in FIG. 16, the
resulting thermoplastic-resin-reinforced sheet material was
continuously cut at a width of 10 mm, and 32 strips of narrow
thermoplastic-resin-reinforced sheet materials were obtained. The
cutter blade and the cutting method adopted at this time were round
cutter blades freely rotatable in response to running of the
thermoplastic-resin-reinforced sheet material and a method in which
the thermoplastic-resin-reinforced sheet material was press-cut
between the cutter blades and a cutter-blade receiving roll. Then,
the resulting narrow thermoplastic-resin-reinforced sheet materials
were taken up in a tape-like form. The wide
thermoplastic-resin-reinforced sheet material was cut at a speed of
10 m/min. (3) The 32 strips of the narrow
thermoplastic-resin-reinforced sheet materials taken up in a
tape-like form were arranged in the width direction in wide
sheet-like structures without leaving gaps. Then, using the
production apparatus as shown in FIG. 14, the sheet materials were
stacked in 45.degree. direction, 0.degree. direction, -45.degree.
direction, and 90.degree. direction into a laminate sheet having a
width of 320 mm, and sewn with an integration thermoplastic-resin
fiber tow with a zigzag stitch in 0.degree. direction at an
interval of 10 mm. Thus, a multilayer
thermoplastic-resin-reinforced sheet material was obtained.
<Evaluation>
[0225] The resulting multilayer thermoplastic-resin-reinforced
sheet material was a multiaxially reinforced sheet material that
was fiber-reinforced in
[45.degree./0.degree./-45.degree./90.degree.], in each layer of
which the narrow reinforcing fibers were formed in a sheet-like
structure and the narrow thermoplastic-resin sheet materials were
joined to a surface thereof. In the respective
thermoplastic-resin-reinforced sheet materials, the reinforcing
fibers were straight, uniformly distributed, and arranged in one
direction. The thermoplastic-resin sheet material joined thereto
prevented the reinforcing fibers from bundling or being unraveled
and frayed. In addition, possibly because the thickness of the thin
reinforcing-fiber sheet materials is small, fray of the reinforcing
fibers at the edges of the cut narrow
thermoplastic-resin-reinforced sheet materials was negligible, and
handling was easy.
Example 3
[0226] A multilayer thermoplastic-resin-reinforced sheet material
was produced by stacking a plurality of
thermoplastic-resin-reinforced sheet materials obtained by going
through (1) to (4) of Example 1 and subjecting them to hot pressing
to bond the layers by thermal adhesion.
<Materials Used>
[0227] The reinforcing fiber tow and the thermoplastic-resin sheet
material were the same as those used in Example 1.
<Production Process>
[0228] (1) A thermoplastic-resin-reinforced sheet material having a
width of 320 mm was formed by going through (1) to (4) of Example
1. (2) The resulting thermoplastic-resin-reinforced sheet materials
were stacked in 45.degree. direction, 0.degree. direction,
-45.degree. direction, and 90.degree. direction into a laminate
sheet having a width of 320 mm by the production apparatus as shown
in FIG. 14, and subjected hot pressing in the production apparatus
as shown in FIG. 18. Thus, a multilayer
thermoplastic-resin-reinforced sheet material was obtained. As the
production apparatus, a single heating roll having a flat roll
surface as shown in FIG. 19A was used. The thermosetting polyimide
resin film (product name: UPILEX-S, thickness: 25 .mu.m,
manufacturer: UBE INDUSTRIES, LTD.) was used as a release film. The
surface temperature of the heating roll was controlled at about
270.degree.. The processing speed was 3 m/min.
<Evaluation>
[0229] Although hot pressing was performed on the entire sheet
using the flat-surface heating roll, not the entire sheet in each
layer was thermally adhered, and there were some parts not
thermally adhered. However, because the respective
reinforcing-fiber sheet materials were thermally adhered to the
overlying and underlying thermoplastic-resin sheet materials in
most part and were unable to come apart, they were obtained as an
integrally bonded multilayer thermoplastic-resin-reinforced sheet
material. The reinforcing fibers were straight also at the
thermally adhered portions, and the layers were in a high-quality
state in which the reinforcing fibers were straight and uniformly
distributed.
Example 4
[0230] Using the following materials, a multilayer
thermoplastic-resin-reinforced sheet material different from
Example 1 was produced.
<Materials Used>
[0231] The reinforcing fiber tow, the thermoplastic-resin sheet
material, and the integration thermoplastic-resin fiber tow were
the same as those used in Example 1.
<Production Process>
[0232] (1) A production apparatus having another set of a
multiple-fiber-tow feeding mechanism, a multiple-fiber-tow
spreading mechanism, a longitudinal-vibration applying mechanism,
and a width-direction-vibration applying mechanism disposed
opposite the heating mechanism of the
thermoplastic-resin-reinforced sheet material producing apparatus
as shown in FIG. 9 was used. Eight filaments of reinforcing fiber
tow TR50S-15K were set 40 mm apart in each of the
multiple-fiber-tow feeding mechanisms. While the
longitudinal-vibration applying mechanisms were applying
longitudinal vibration to the reinforcing fiber tows, the
multiple-fiber-tow spreading mechanisms spread the reinforcing
fiber tows into reinforcing fiber multi-filament spread threads
having a width of about 40 mm. Then, the width-direction-vibration
applying mechanisms applied vibration in the width direction to the
reinforcing fiber multi-filament spread threads to form continuous
reinforcing-fiber sheet materials having a width about 320 mm and a
fiber weight (fiber weight per unit area) of about 25 g/m.sup.2
having no gaps between the reinforcing fiber multi-filament spread
threads. (2) Thereafter, while the reinforcing-fiber sheet
materials were continuously fed from both sides of the heating
mechanism, a thermoplastic-resin sheet material was continuously
inserted between the reinforcing-fiber sheet materials. Then, the
reinforcing-fiber sheet materials were joined to both surfaces of
the thermoplastic-resin sheet material by the heating mechanism. At
this time, the temperature of the heating mechanism was controlled
at about 270.degree.. The thermosetting polyimide resin film
(product name: UPILEX-S, thickness: 25 .mu.m, manufacturer: UBE
INDUSTRIES, LTD.), serving as a release film, was fed together with
the reinforcing-fiber sheet materials. The speed at which the
reinforcing fiber tows were spread and formed into the
reinforcing-fiber sheet materials, and the processing speed at
which the reinforcing-fiber sheet materials were joined to both
surfaces of the thermoplastic-resin sheet material were both 10
m/min. (3) By removing the release film from the base fabric
discharged from the cooling mechanism, a
thermoplastic-resin-reinforced sheet material as shown in FIG. 3A,
in which the reinforcing-fiber sheet materials were joined to both
surfaces of the thermoplastic-resin sheet material, was obtained.
(4) The resulting thermoplastic-resin-reinforced sheet materials
were stacked in 45.degree. direction, 0.degree. direction,
-45.degree. direction, and 90.degree. direction into a laminate
sheet having a width of 320 mm by the production apparatus as shown
in FIG. 14, and sewn with the integration thermoplastic-resin fiber
tow with a zigzag stitch in 0.degree. direction at an interval of
20 mm. Thus, a multilayer thermoplastic-resin-reinforced sheet
material was obtained.
<Evaluation>
[0233] The resulting multilayer thermoplastic-resin-reinforced
sheet material was a multiaxially reinforced sheet material that
was fiber-reinforced in
[45.degree./0.degree./-45.degree./90.degree.], in each layer of
which the reinforcing-fiber sheet materials were joined to both
surfaces of the thermoplastic-resin sheet material. In the
respective thermoplastic-resin-reinforced sheet materials, the
reinforcing fibers were straight, uniformly distributed, and
arranged in one direction. The thermoplastic-resin sheet material
joined thereto prevented the reinforcing fibers from bundling or
being unraveled and frayed. In addition, the
thermoplastic-resin-reinforced sheet materials had no problems,
such as curling of the edges, and were stacked while the flatness
of the sheet was maintained.
Example 5
[0234] Using the multilayer thermoplastic-resin-reinforced sheet
material produced in Example 2, a recessed thermoplastic-resin
multilayer reinforced molding was produced.
<Production Process>
[0235] (1) The multilayer thermoplastic-resin-reinforced sheet
material obtained in Example 2 was cut in a longitudinal direction
(0.degree. direction) into four pieces having a length of 320 mm,
and, as shown in FIG. 20, stacked in a shaping lower metal mold
with sequences of [45.degree./0.degree./-45.degree./90.degree.],
[45.degree./0.degree./-45.degree./90.degree.],
[90.degree./-45.degree./0.degree./45.degree.], and
[90.degree./-45.degree./0.degree./45.degree.]. The shaping lower
metal mold had a recess with a width of 250 mm, a length of 250 mm,
and a depth of 20 mm, and was rounded at curved portions and
corners. (2) After the shaping lower metal mold was placed in a hot
press molding apparatus, a shaping upper metal mold was lowered.
Then, while a pressure of 0.1 MPa was applied, the temperature of
the shaping metal mold was raised to 270.degree. in 30 minutes. (3)
After the temperature was raised, the shaping upper metal mold was
lowered and hot pressing was performed on the base fabric at a
pressure of 2 MPa for 60 seconds. Then, the shaping metal molds,
still applying pressure, were rapidly cooled by water cooling. The
cooling time was about 10 minutes. After cooling, the shaping upper
metal mold was raised and a thermoplastic-resin multilayer
reinforced molding was obtained.
<Evaluation>
[0236] A recessed thermoplastic-resin multilayer reinforced molding
having a thickness of about 0.8 mm and a fiber volume content of
about 58% was obtained. No trace of the integration
thermoplastic-resin fiber tow used in stitching was left on the
surface of the molding, and the surface of the molding exhibited
excellent smoothness. In addition, the reinforcing fibers on the
surface were straight and had excellent distribution. The molding
was cut and the cross section was observed. As a result, it was
confirmed that the molding exhibited excellent straightness and
distribution of the reinforcing fibers and had few gaps (voids).
Furthermore, it was confirmed that the molding was high quality and
had no delamination at the curved portions and corners. Because the
multilayer thermoplastic-resin-reinforced sheet material was formed
of the narrow thermoplastic-resin-reinforced sheet materials, the
shape conformability of the sheet material at the curved portions
and the corners was excellent. Thus, forming was easy.
Example 6
[0237] Using the multilayer thermoplastic-resin-reinforced sheet
material produced in Example 1, a recessed thermoplastic-resin
multilayer reinforced molding was produced through a production
process different from that of Example 4.
<Production Process>
[0238] (1) The multilayer thermoplastic-resin-reinforced sheet
material obtained in Example 1 was cut in a longitudinal direction
(0.degree. direction) into four pieces having a length of 320 mm,
and, as shown in FIG. 21, stacked on a flat lower metal mold with
sequences of [45.degree./0.degree./-45.degree./90.degree.],
[45.degree./0.degree./-45.degree./90.degree.],
[90.degree./-45.degree./0.degree./45.degree.], and
[90.degree./-45.degree./0.degree./45.degree.]. The flat lower metal
mold had a width of 350 mm and a length of 350 mm. (2) After the
flat lower metal mold was placed in a hot press molding apparatus,
a flat upper metal mold was lowered. Then, while a pressure of 0.1
MPa was applied, the temperature of the flat metal mold was raised
to 270.degree. in 10 minutes. (3) After the temperature was raised,
the flat upper metal mold was lowered and hot pressing was
performed on the base fabric at a pressure of 2 MPa for 60 seconds.
Then, the flat metal molds, still applying pressure, were rapidly
cooled by water cooling. The cooling time was about 10 minutes.
After cooling, the flat upper metal mold was raised and a
plate-shaped thermoplastic-resin multilayer reinforced molding was
obtained. (4) The resulting plate-shaped thermoplastic-resin
multilayer reinforced molding was placed in a far-infrared heating
unit controlled at 300.degree. and was left for about 3 minutes so
that the plate-shaped thermoplastic-resin multilayer reinforced
molding was sufficiently softened. (5) The plate-shaped
thermoplastic-resin multilayer reinforced molding was placed in a
shaping lower metal mold in a cold press molding apparatus whose
temperature was controlled at about 80.degree., and the shaping
upper metal mold was lowered. Then, molding was performed while a
pressure of 1 MPa was applied for about 60 seconds. Thereafter, the
shaping upper metal mold was raised and a thermoplastic-resin
multilayer reinforced molding was obtained.
<Evaluation>
[0239] A recessed thermoplastic-resin multilayer reinforced molding
having a thickness of about 0.8 mm and a fiber volume content of
about 58% was obtained. No trace of the integration
thermoplastic-resin fiber tow used in stitching was left on the
surface of the molding, and the surface of the molding exhibited
excellent smoothness. In addition, the reinforcing fibers on the
surface were straight and had excellent distribution. The molding
was cut and the cross section was observed. As a result, it was
confirmed that the molding exhibited excellent straightness and
distribution of the reinforcing fibers and had few gaps (voids).
Furthermore, it was confirmed that the molding was high quality and
had no delamination at the curved portions and corners.
Example 7
[0240] Using the multilayer thermoplastic-resin-reinforced sheet
material produced in Example 3, a plate-shaped thermoplastic-resin
multilayer reinforced molding was produced.
<Production Process>
[0241] (1) The multilayer thermoplastic-resin-reinforced sheet
material obtained in Example 3 was cut in a longitudinal direction
(0.degree. direction) into two pieces having a length of 320 mm,
and, as shown in FIG. 21, stacked in a flat lower metal mold with
sequences of [45.degree./0.degree./-45.degree./90.degree.] and
[90.degree./-45.degree./0.degree./45.degree.]. The flat lower metal
mold had a width of 350 mm and a length of 350 mm. (2) After the
flat lower metal mold was placed in a hot press molding apparatus,
a flat upper metal mold was lowered. Then, while a pressure of 0.1
MPa was applied, the temperature of the flat metal mold was raised
to 270.degree. in 10 minutes. (3) After the temperature was raised,
the flat upper metal mold was lowered and hot pressing was
performed on the base fabric at a pressure of 2 MPa for 60 seconds.
Then, the flat metal molds, still applying pressure, were rapidly
cooled by water cooling. The cooling time was about 15 minutes.
After cooling, the flat upper metal mold was raised and a
plate-shaped thermoplastic-resin multilayer reinforced molding was
obtained.
<Evaluation>
[0242] A plate-shaped thermoplastic-resin multilayer reinforced
molding having a thickness of about 0.4 mm and a fiber volume
content of about 60% was obtained. No trace of bonding by thermal
adhesion was left on the surface of the molding, and the surface of
the molding exhibited excellent smoothness. In addition, the
reinforcing fibers on the surface were straight and had excellent
distribution. The molding was cut and the cross section was
observed. As a result, it was confirmed that the molding exhibited
excellent straightness and distribution of the reinforcing fibers
and had few gaps (voids).
Example 8
[0243] Using the following materials, a
thermoplastic-resin-reinforced sheet material was produced.
<Materials Used>
(Fiber Tow Used as Reinforcing Fiber Tow)
[0244] TR50S-15K, fiber diameter: about 7 .mu.m, number of fibers:
15000, produced by MITSUBISHI RAYON CO., LTD.
(Resin Used as Thermoplastic-Resin Sheet Material)
[0245] Nylon 6 resin pellets, produced by Mitsubishi Plastics,
Inc.
(Resin Used as Bonding Thermoplastic-Resin Material)
[0246] Copolymerized polyamide resin powder, CM842P48, low-melting
point (115.degree. C.) resin, produced by Toray Industries,
Inc.
<Production Process>
[0247] (1) Thirteen filaments of reinforcing fiber tow TR50S-15K
were set 24 mm apart in the production apparatus as shown in FIG.
10. Using the multiple-fiber-tow spreading mechanism for
simultaneously spreading multiple filaments by air and the
longitudinal-vibration applying mechanism, the reinforcing fiber
tows were spread into reinforcing fiber multi-filament spread
threads having a width of 24 mm. Then, the reinforcing fiber
multi-filament spread threads were vibrated in the width direction
by the width-direction-vibration applying mechanism, and a
reinforcing-fiber sheet material having no gaps between the
reinforcing fiber multi-filament spread threads was obtained. The
resulting reinforcing-fiber sheet material had a width of 310 mm
and a fiber weight (fiber weight per unit area) of about 42
g/m.sup.2. (2) An apparatus consisting of an extruder and a T-die
was disposed instead of the thermoplastic-resin sheet material
feeding mechanism shown in FIG. 10. Nylon 6 pellets were inserted
in the apparatus, and while a nylon 6 film having a width of 320 mm
and a thickness 15 .mu.m was being produced, the nylon 6 resin film
was thermally adhered to a surface of the reinforcing-fiber sheet
material. A release sheet material was not used. The heating
temperature of the heating rolls 72 for bonding the
reinforcing-fiber sheet material and the nylon 6 resin film was
controlled at 150.degree.. (3) While the sheet, formed of the
reinforcing-fiber sheet material and the nylon 6 resin film joined
to a surface thereof, was allowed to run, copolymerized polyamide
resin powder, serving as a bonding thermoplastic-resin material,
was uniformly dispersed and deposited on the surface of the sheet
on the nylon 6 resin film side, using the powder-dispersing
apparatus 71. The amount of dispersion was about 0.3 g/m.sup.2, and
an amount equivalent to about 0.7% of the weight of the reinforcing
fiber tows was deposited. The heating temperature of the heating
rolls 72 were controlled at 120.degree.. The speed at which the
reinforcing-fiber sheet material was produced, the speed at which
the nylon 6 resin film was produced by extrusion molding, and the
speed at which the copolymerized polyamide resin powder was
dispersed and deposited were about 8 m/min.
<Evaluation>
[0248] In the resulting thermoplastic-resin-reinforced sheet
material, the reinforcing fibers constituting the reinforcing-fiber
sheet material were straight and uniformly distributed. The nylon 6
resin film was joined to the entire reinforcing fiber sheet and
stabilized the shape of the reinforcing fiber multi-filament spread
threads. No gaps or bundled fibers were formed in the
reinforcing-fiber sheet material. The copolymerized polyamide resin
powder, serving as a bonding thermoplastic-resin material, was
uniformly dispersed and deposited on a surface of the
thermoplastic-resin-reinforced sheet material on the nylon 6 resin
film side.
Example 9
[0249] Using the following materials, a
thermoplastic-resin-reinforced sheet material was produced.
<Materials Used>
[0250] The reinforcing fiber tow and the bonding
thermoplastic-resin material were the same as those in Example
8.
(Resin Used as Thermoplastic-Resin Sheet Material)
[0251] PEI (polyetherimide) resin film, film thickness: 15 .mu.m,
produced by Mitsubishi Plastics, Inc.
<Production Process>
[0252] (1) Using the production apparatus as shown in FIG. 12 and
the method described in (1) of Example 8, a reinforcing-fiber sheet
material having a width of 310 mm and a fiber weight of about 42
g/m.sup.2 was obtained. (2) While a PEI resin film, serving as a
thermoplastic-resin sheet material, was allowed to run,
copolymerized polyamide resin powder, serving as a bonding
thermoplastic-resin material, was uniformly dispersed and deposited
on a surface thereof, with the powder-dispersing apparatus. The
amount of dispersion was about 0.3 g/m.sup.2, which was about 0.7%
of the weight of the reinforcing fiber tows. (3) The PEI resin
film, on which the copolymerized polyamide resin powder was
dispersed, was joined to the reinforcing-fiber sheet material, and,
together with a release sheet material, allowed to run over the
heating roll and the cooling roll. Thus, the copolymerized
polyamide resin powder was melted, and a
thermoplastic-resin-reinforced sheet material formed of the
reinforcing-fiber sheet material and the PEI resin film joined
thereto was obtained. At this time, the temperature of the heating
roll was controlled at about 120.degree.. Release paper was fed as
the release sheet material. The speed at which the
reinforcing-fiber sheet material was produced, the speed at which
the copolymerized polyamide resin powder was dispersed and
deposited on the PEI resin film, and the speed at which the
thermoplastic-resin-reinforced sheet material was joined to the
reinforcing-fiber sheet material to produce the
thermoplastic-resin-reinforced sheet material were about 10
m/min.
<Evaluation>
[0253] In the resulting thermoplastic-resin-reinforced sheet
material, the reinforcing fibers constituting the reinforcing-fiber
sheet material were straight and uniformly distributed. The
reinforcing fiber multi-filament spread threads had stable shape by
being attached to the PEI resin film. In addition, the
reinforcing-fiber sheet material did not have gaps or bundled
fibers. Furthermore, the PEI resin film hardly shrank by heating
and was joined to the reinforced sheet material while stabilizing
the shape of the sheet.
Example 10
[0254] Using the following materials, a
thermoplastic-resin-reinforced sheet material was produced.
<Materials Used>
[0255] The reinforcing fiber tow was the same as that of Example
8.
(Resin Used as Thermoplastic-Resin Sheet Material)
[0256] PPS (polyphenylene sulfide) resin film, film thickness: 15
.mu.m, produced by Toray Industries, Inc.
(Resin Used as Bonding Thermoplastic-Resin Material)
[0257] Polyamide resin powder, SP-500, melting point: 165.degree.
C., produced by Toray Industries, Inc.
<Production Process>
[0258] (1) According to (1) of Example 8, a reinforcing-fiber sheet
material having a width of 310 mm and a fiber weight of about 42
g/m.sup.2 was obtained. (2) While a PPS resin film, serving as a
thermoplastic-resin sheet material, was allowed to run, polyamide
resin powder, serving as a bonding thermoplastic-resin material,
was uniformly dispersed and deposited on a surface thereof with a
powder-dispersing apparatus. The amount of dispersion was about 0.5
g/m.sup.2, which was about 1.2% of the weight of the reinforcing
fiber tows. (3) The PPS resin film, on which the polyamide resin
powder was dispersed, was joined to the reinforcing-fiber sheet
material, and, together with a release sheet material, allowed to
run over the heating roll and the cooling roll. Thus, the polyamide
resin powder was melted and a thermoplastic-resin-reinforced sheet
material formed of the reinforcing-fiber sheet material and the PPS
resin film joined thereto was obtained. At this time, the
temperature of the heating roll was controlled at about
200.degree.. Release paper was fed as the release sheet material.
The speed at which the reinforcing-fiber sheet material was
produced, the speed at which the polyamide resin powder was
dispersed and deposited on the PPS resin film, and the speed at
which the thermoplastic-resin-reinforced sheet material was joined
to the reinforcing-fiber sheet material to produce the
thermoplastic-resin-reinforced sheet material were about 10
m/min.
<Evaluation>
[0259] Similarly to Example 9, in the resulting
thermoplastic-resin-reinforced sheet material, the reinforcing
fibers constituting the reinforcing-fiber sheet material were
straight and uniformly distributed. In addition, the reinforcing
fiber multi-filament spread threads had stable shape by being
attached to the PPS resin film. In addition, the reinforcing-fiber
sheet material did not have gaps or bundled fibers. Because the
sheet shape of the PPS resin film was stable, an easy-to-handle
thermoplastic-resin-reinforced sheet material was obtained.
Example 11
[0260] Using the following materials, a
thermoplastic-resin-reinforced sheet material was produced.
<Materials Used>
(Fiber Tow Used as Reinforcing Fiber Tow)
[0261] MR60H-24K, fiber diameter: about 5.4 .mu.m, number of
fibers: 24000, produced by MITSUBISHI RAYON CO., LTD.
(Resin Used as Thermoplastic-Resin Sheet Material)
[0262] Polyetherimide (PEI) resin film, film thickness: 15 .mu.m,
produced by Mitsubishi Plastics, Inc.
(Resin Used as Bonding Thermoplastic-Resin Material)
[0263] Copolymerized polyamide resin powder, CM842P48, low-melting
point (115.degree. C.) resin, produced by Toray Industries,
Inc.
<Production Process>
[0264] (1) A production apparatus having another set of a
multiple-fiber-tow feeding mechanism, a multiple-fiber-tow
spreading mechanism, a longitudinal-vibration applying mechanism,
and a width-direction-vibration applying mechanism disposed
opposite the heating mechanism of the
thermoplastic-resin-reinforced sheet material producing apparatus
as shown in FIG. 10 was used. Seven filaments of reinforcing fiber
tow MR60H-24K were set 45 mm apart in each of the
multiple-fiber-tow feeding mechanisms. While the
longitudinal-vibration applying mechanisms were applying
longitudinal vibration to the reinforcing fiber tows, the
multiple-fiber-tow spreading mechanisms spread the reinforcing
fiber tows into reinforcing fiber multi-filament spread threads
having a width of about 45 mm. Then, the width-direction-vibration
applying mechanisms applied vibration in the width direction to the
reinforcing fiber multi-filament spread threads to form continuous
reinforcing-fiber sheet materials having a width of about 315 mm
and a fiber weight (fiber weight per unit area) of about 22
g/m.sup.2 having no gaps between the reinforcing fiber
multi-filament spread threads. (2) Thereafter, while the
reinforcing-fiber sheet materials were continuously fed from both
sides of the heating mechanism, a thermoplastic-resin sheet
material was continuously inserted between the reinforcing-fiber
sheet materials. Then, the reinforcing-fiber sheet materials were
joined to both surfaces of the thermoplastic-resin sheet material
by the heating mechanism. At this time, the temperature of the
heating mechanism was controlled at about 350.degree.. The
thermosetting polyimide resin film (product name: UPILEX-S,
thickness: 25 .mu.m, manufacturer: UBE INDUSTRIES, LTD.), serving
as a release film, was fed together with the reinforcing-fiber
sheet materials. (3) While the sheet material, in which the
reinforcing-fiber sheet materials were joined to both surfaces of
the thermoplastic-resin sheet material, was allowed to run,
copolymerized polyamide resin powder, serving as a bonding
thermoplastic-resin material, was uniformly dispersed and deposited
on a surface of the reinforcing-fiber sheet materials of the sheet
material with a powder-dispersing apparatus. The amount of
dispersion was about 0.4 g/m.sup.2, which was about 1% of the
weight of the reinforcing fiber tows. The heating temperature of
the heating roll was controlled at 120.degree.. The speed at which
the reinforcing fiber tows were spread and formed into the
reinforcing-fiber sheet materials, the processing speed at which
the reinforcing-fiber sheet materials were joined to both surfaces
of the thermoplastic-resin sheet material, and the speed at which
the copolymerized polyamide resin powder was dispersed and
deposited were about 10 m/min. (4) By removing the release film
from the base fabric discharged from the cooling mechanism, a
thermoplastic-resin-reinforced sheet material in which the
reinforcing-fiber sheet materials were joined to both surfaces of
the thermoplastic-resin sheet material and in which the
copolymerized polyamide resin powder, serving as a bonding
thermoplastic-resin material, was deposited on a surface of one of
the reinforcing-fiber sheet materials was obtained.
<Evaluation>
[0265] In the resulting thermoplastic-resin-reinforced sheet
material, the reinforcing fibers constituting the reinforcing-fiber
sheet materials were straight and uniformly distributed. In
addition, the reinforcing-fiber sheet materials were joined to the
thermoplastic-resin sheet material, which stabilized the shape of
the reinforcing fiber multi-filament spread threads. No gaps or
bundled fibers were formed in the reinforcing-fiber sheet
materials. The copolymerized polyamide resin powder, serving as a
bonding thermoplastic-resin material, was uniformly dispersed and
deposited on the surface of one of the reinforcing-fiber sheet
materials of the thermoplastic-resin-reinforced sheet material.
Furthermore, the thermoplastic resin reinforcing-fiber sheet
material had no problems, such as curling of the edges, and the
flatness of the sheet was maintained.
Example 12
[0266] A multilayer thermoplastic-resin-reinforced sheet material
was produced from the thermoplastic-resin-reinforced sheet material
obtained by the method of Example 9.
<Materials Used>
[0267] The reinforcing fiber tow, the thermoplastic-resin sheet
material, and the bonding thermoplastic-resin material were the
same as those in Example 9.
<Production Process>
[0268] (1) A thermoplastic-resin-reinforced sheet material having a
width of 310 mm was formed by going through (1) to (3) of Example
9. The amount of dispersion of the bonding thermoplastic-resin
material was about 0.4 g/m.sup.2, and an amount equivalent to about
1% of the weight of the reinforcing fiber tows was deposited. (2)
Using the production apparatus as shown in FIG. 10, copolymerized
polyamide resin powder, serving as a bonding thermoplastic-resin
material, was uniformly dispersed and deposited on the surface of
the resulting thermoplastic-resin-reinforced sheet material on the
PEI resin film side with the powder-dispersing apparatus. The
amount of dispersion was about 0.2 g/m.sup.2, which was about 0.5%
of the weight of the reinforcing fiber tows. (3) Using the
production apparatus as shown in FIG. 14, the resulting
thermoplastic-resin-reinforced sheet materials were stacked in
45.degree. direction, 0.degree. direction, -45.degree. direction,
and 90.degree. direction into a laminate sheet having a width of
310 mm. Then, the copolymerized polyamide resin powder was melted
by the heating mechanism, and the stacked
thermoplastic-resin-reinforced sheet materials were bonded
together. Thus, a multilayer thermoplastic-resin-reinforced sheet
material was obtained. At this time, the temperature of the heating
roll was controlled at about 120.degree.. Release paper was fed as
a release sheet material.
<Evaluation>
[0269] The resulting multilayer thermoplastic-resin-reinforced
sheet material was a multiaxially reinforced sheet material that
was fiber-reinforced in
[45.degree./0.degree./-45.degree./90.degree.], in each layer of
which the PEI resin film was joined to a surface of the reinforcing
fibers formed in a sheet-like structure. In the respective
thermoplastic-resin-reinforced sheet materials, the reinforcing
fibers were straight and uniformly distributed, and the PEI resin
film hardly shrank by heating and stabilized the shape of the
sheet. The respective thermoplastic-resin-reinforced sheet
materials were bonded together by the copolymerized polyamide resin
powder. Thus, a multilayer thermoplastic-resin-reinforced sheet
material having excellent drapeability and quality was obtained.
The amount of the copolymerized polyamide resin used in each
thermoplastic-resin-reinforced sheet material was about 1.5% of the
amount of the carbon fiber used.
Example 13
[0270] A plurality of narrow thermoplastic-resin-reinforced sheet
material were obtained from the thermoplastic-resin-reinforced
sheet material formed by going through (1) and (2) of Example 12.
Then, a multilayer thermoplastic-resin-reinforced sheet material
was produced.
<Materials Used>
[0271] The reinforcing fiber tow, the thermoplastic-resin sheet
material, and the bonding thermoplastic-resin material were the
same as those in Example 9.
<Production Process>
[0272] (1) A thermoplastic-resin-reinforced sheet material having a
width of 310 mm was formed by going through (1) and (2) of Example
12. (2) Using the production apparatus as shown in FIG. 15, the
resulting thermoplastic-resin-reinforced sheet material was
continuously cut at a width of 10 mm, and 31 strips of narrow
thermoplastic-resin-reinforced sheet materials were obtained. The
cutter blade and the cutting method adopted at this time were round
cutter blades freely rotatable in response to running of the
thermoplastic-resin-reinforced sheet material and a method in which
the thermoplastic-resin-reinforced sheet material was press-cut
between the cutter blades and a cutter-blade receiving roll. Then,
the resulting narrow thermoplastic-resin-reinforced sheet materials
were taken up in a tape-like form. The wide
thermoplastic-resin-reinforced sheet material was cut at a speed of
10 m/min. (3) The 31 strips of the narrow
thermoplastic-resin-reinforced sheet materials, taken up in a
tape-like form, were arranged in the width direction in wide
sheet-like structures without leaving gaps. Then, using the
production apparatus as shown in FIG. 14, the sheet materials were
stacked in 45.degree. direction, 0.degree. direction, -45.degree.
direction, and 90.degree. direction into a laminate sheet having a
width of 310 mm. Then, the copolymerized polyamide resin powder was
melted by the heating mechanism, and the stacked
thermoplastic-resin-reinforced sheet materials were bonded
together. Thus, a multilayer thermoplastic-resin-reinforced sheet
material was obtained. At this time, the temperature of the heating
roll was controlled at about 120.degree.. Release paper was fed as
a release sheet material.
<Evaluation>
[0273] The resulting multilayer thermoplastic-resin-reinforced
sheet material was a multiaxially reinforced sheet material that
was fiber-reinforced in
[45.degree./0.degree./-45.degree./90.degree.], in each layer of
which the PEI resin film was joined to a surface of the reinforcing
fibers formed in a sheet-like structure. The reinforcing fibers in
the narrow thermoplastic-resin-reinforced sheet materials in the
respective layers were straight and uniformly distributed, and the
PEI resin film hardly shrank by heating and stabilized the shape of
the sheet. In addition, fray of the reinforcing fibers at the edges
of the cut narrow thermoplastic-resin-reinforced sheet materials
was negligible, and handling was easy. Furthermore, because each
layer consists of the narrow thermoplastic-resin-reinforced sheet
materials, the multilayer thermoplastic-resin-reinforced sheet
material had great drapeability.
Example 14
[0274] Using the multilayer thermoplastic-resin-reinforced sheet
material produced in Example 12, a recessed thermoplastic-resin
multilayer reinforced molding was produced.
<Production Process>
[0275] (1) The multilayer thermoplastic-resin-reinforced sheet
material obtained in Example 12 was cut in a longitudinal direction
(0.degree. direction) into four pieces having a length of 310 mm,
and stacked in a recessed shaping metal mold with sequences of
[45.degree./0.degree./-45.degree./90.degree.],
[45.degree./0.degree./-45.degree./90.degree.],
[45.degree./0.degree./-45.degree./90.degree.],
[90.degree./-45.degree./0.degree./45.degree.],
[90.degree./-45.degree./0.degree./45.degree.], and
[90.degree./-45.degree./0.degree./45.degree.]. The shaping metal
mold had a recess with a width of 250 mm, a length of 250 mm, and a
depth of 20 mm, and was rounded at curved portions and corners. (2)
After the recessed shaping metal mold was placed in a hot press
molding apparatus, a projected shaping metal mold was lowered.
Then, while a pressure of 0.1 MPa was applied, the temperature of
the shaping metal mold was raised to 380.degree. in 60 minutes. (3)
After the temperature was raised, the projected shaping metal mold
was lowered and hot pressing was performed on the base fabric at a
pressure of 1 MPa for 60 seconds. Then, the shaping metal molds,
still applying pressure, were slowly cooled. The cooling time was
about 120 minutes. After cooling, the projected shaping metal mold
was raised and a thermoplastic-resin multilayer reinforced molding
was obtained.
<Evaluation>
[0276] A recessed thermoplastic-resin multilayer reinforced molding
having a thickness of about 1 mm and a fiber volume content of
about 60% was obtained. The surface of the molding exhibited
excellent smoothness. In addition, the reinforcing fibers on the
surface were straight and had excellent distribution. The molding
was cut and the cross section was observed. As a result, it was
confirmed that the molding exhibited excellent straightness and
distribution of the reinforcing fibers and had few gaps (voids).
Furthermore, it was confirmed that the molding was high quality and
had no delamination at the curved portions and corners.
Example 15
[0277] Using the following materials and the molding process
explained in FIG. 23, a recessed thermoplastic-resin multilayer
reinforced molding was produced.
<Materials Used>
(Reinforcing Fiber Tow)
Carbon Fiber Tow
[0278] TR50S-15K, fiber diameter: about 7 .mu.m, number of fibers:
15000, produced by MITSUBISHI RAYON CO., LTD.
(Thermoplastic Resin)
Polyamide Resin
[0279] Nylon 6 resin film, film thickness: 20 .mu.m, produced by
Mitsubishi Chemical Corporation
<Production Process>
[0280] (1) Sixteen filaments of reinforcing fiber tow TR50S-15K
were set 20 mm apart. Using a known method for simultaneously
spreading multiple filaments by air (refer to Japanese Translation
of PCT International Application, Publication No. 2007-518890),
each reinforcing fiber tow was spread to a width of about 20 mm.
(2) The reinforcing fiber multi-filament spread threads spread to a
width of 20 mm were vibrated in the width direction and formed into
a reinforcing-fiber sheet material having no gaps between the
reinforcing fiber multi-filament spread threads. The resulting
reinforcing-fiber sheet material had a width of about 320 mm and a
fiber weight (fiber weight per unit area) of about 50 g/m.sup.2.
(3) A thermoplastic-resin sheet material, while being heated, was
continuously joined to the resulting reinforcing-fiber sheet
material. At this time, the heating temperature was controlled at
about 270.degree. C. A thermosetting polyimide resin film (product
name: UPILEX-S, thickness: 25 .mu.m, produced by UBE INDUSTRIES,
LTD.), serving as a release film, was fed together with the
reinforcing-fiber sheet material. The
thermoplastic-resin-reinforced sheet material was joined to the
reinforcing-fiber sheet material at a speed of 10 m/min. (4) After
heating and cooling, by removing the release film from the base
fabric, a thermoplastic-resin-reinforced sheet material formed of
the reinforcing-fiber sheet material and the thermoplastic-resin
sheet material joined to a surface thereof was obtained. (5) From
the resulting thermoplastic-resin-reinforced sheet material, sheets
having a size of 320 mm square in which, assuming that the fiber
direction was 0.degree. direction, fibers are arranged in 0.degree.
direction, 90.degree. direction, 45.degree. direction, and
-45.degree. direction were cut out and formed into a laminated
sheet material of
[(45.degree./0.degree./-45.degree./90.degree.).sub.3].sub.s. (6)
After the laminated sheet material was placed on a recessed iron
shaping mold (lower mold) having a thickness of 1 mm, a projected
iron shaping mold (upper mold) having a thickness of 1 mm was
placed. As a release treatment, a release agent (Frekote 44-NC
produced by Henkel AG & Co. KGaA) was sprayed on the mold
surfaces of the shaping molds. Then, the shaping mold pair, between
which the laminated sheet material was placed, was placed in a hot
press. The shaping molds were placed on the lower mold of the hot
press mold preliminarily heated to 270.degree. C., then the upper
mold of the hot press mold was immediately lowered to apply
pressure. At this time, the lower mold of the hot press mold had a
shape such that the recessed shaping mold can be fitted thereto and
the upper mold of the hot press mold had a shape such that it can
fit the projected shaping mold and apply pressure thereto. Hot
pressing was performed at a pressure of 2 MPa for 5 minutes. (7)
After the hot pressing, the shaping molds were taken out of the hot
press and placed in a cold press. The shaping molds were placed on
the lower mold of the cold press mold preliminarily cooled to about
20.degree. by water cooling, and the upper mold of the cold press
mold was immediately lowered to apply pressure. Similarly to the
hot press mold, the lower mold of the cold press mold had a shape
such that the recessed shaping mold can be fitted thereto and the
upper mold of the cold press had a shape such that it can fit the
projected shaping mold and apply pressure thereto. Cold pressing
was performed at a pressure of 2 MPa for 3 minutes. Then, the
shaping molds were taken out of the cold press, and a
thermoplastic-resin composite-material molding was obtained.
<Evaluation>
[0281] The resulting thermoplastic-resin composite-material molding
was finished as a recessed molding having no warpage or the like,
having a thickness of about 1.2 mm and a fiber volume content of
about 58%. A part of the molding was cut and the cross section was
observed. As a result, it was confirmed that the fiber tows were
uniformly impregnated with the thermoplastic resin and the fibers
were uniformly distributed. Furthermore, the curved shape, the
corner shape, etc. of the molding were precisely formed so as to
conform to the surface of the shaping mold.
Example 16
[0282] Using the laminated sheet material obtained by going through
(1) to (5) of Example 15, molding was performed.
<Production Process>
[0283] (1) By going through (1) to (5) of Example 15, a laminated
sheet material having a size of 320 mm square, stacked in
[(45.degree./0.degree./-45.degree./90.degree.).sub.3].sub.s was
produced. (2) After the laminated sheet material was placed on a
recessed iron shaping mold (lower mold) having a thickness of 1 mm,
a projected iron shaping mold (upper mold) having a thickness of 1
mm was placed. The peripheral portions of the upper and lower
shaping molds were sealed with a seal member made of heat-resisting
rubber to form an airtight structure. As a release treatment,
(Frekote 44-NC, produced by Henkel AG & Co. KGaA) was sprayed
on the surfaces of the shaping molds. Then, the air in the shaping
molds was sucked (discharged) to bring the inside of the shaping
molds into a reduced pressure state of 10 Torr or less. (3) The
recessed and projected shaping molds accommodating the laminated
sheet material, the inside of which being in a reduced pressure
state, was placed in a hot press. The shaping molds were placed on
the lower mold of the hot press mold preliminarily heated to
270.degree. C., then the upper mold of the hot press mold was
immediately lowered to apply pressure. At this time, similarly to
the case of Example 15, the lower mold of the hot press mold had a
shape such that the recessed shaping mold can be fitted thereto and
the upper mold of the hot press mold had a shape such that it can
fit the projected shaping mold and apply pressure thereto. Hot
pressing was performed at a pressure of 2 MPa for 3 minutes. The
air in the shaping molds was continuously sucked (discharged)
during hot pressing by the hot press to maintain the inside of the
shaping molds in a reduced pressure state of 10 Torr or less. (4)
After the hot pressing, the shaping molds, the inside of which was
still in a reduced pressure state, were taken out of the hot press
and then placed in a cold press. The shaping molds were placed on
the lower mold of the cold press mold preliminarily cooled to about
20.degree. by water cooling, and the upper mold of the cold press
mold was immediately lowered to apply pressure. At this time,
similarly to Example 1, the lower mold of the cold press mold had a
shape such that the recessed shaping mold can be fitted thereto and
the upper mold of the cold press had a shape such that it can fit
the projected shaping mold and apply pressure thereto. Cold
pressing was performed at a pressure of 2 MPa for 3 minutes. The
air in the shaping molds was continuously sucked (discharged) while
cold pressing was performed by the cold press on the shaping molds,
to maintain the inside of the shaping molds in a reduced pressure
state of 10 Torr or less. (5) Then, the shaping molds were taken
out of the cold press. After the inside of the shaping molds in a
reduced pressure state was brought back to an atmospheric pressure
state, a thermoplastic-resin composite-material molding was
obtained from the inside of the shaping mold.
<Evaluation>
[0284] The resulting thermoplastic-resin composite-material molding
was finished as a recessed molding having no warpage or the like,
having a thickness of about 1.2 mm and a fiber volume content of
about 58%. A part of the molding was cut and the cross section was
observed. As a result, it was confirmed that the fiber tows were
uniformly impregnated with the thermoplastic resin and the fibers
were uniformly distributed, in spite of reduced hot pressing time.
Furthermore, the curved shape, the corner shape, etc. of the
molding were precisely formed so as to conform to the surface of
the shaping mold.
Example 17
[0285] Using the following materials, a flat thermoplastic-resin
multilayer reinforced molding was produced by the molding method
explained in FIG. 26.
<Materials Used>
(Reinforcing Fiber Tow)
Carbon Fiber Tow
[0286] MR60H-24K, fiber diameter: about 5.4 .mu.m, number of
fibers: 24000, produced by MITSUBISHI RAYON CO., LTD.
(Thermoplastic Resin)
Polyetherimide (PEI) Resin Film
[0287] Superio UT, thickness: 15 .mu.m, produced by Mitsubishi
Plastics, Inc.
(Resin Used as Bonding Thermoplastic-Resin Material)
Copolymerized Polyamide Resin Powder
[0288] CM842P48, low-melting point (115.degree. C.) resin, produced
by Toray Industries, Inc.
<Production Process>
[0289] (1) Thirteen filaments of reinforcing fiber tow MR60H-24K
were set 24 mm apart. Using a known method for simultaneously
spreading multiple filaments by air (refer to Japanese Translation
of PCT International Application, Publication No. 2007-518890), the
reinforcing fiber tows were spread to a width of about 24 mm. (2)
The reinforcing fiber multi-filament spread threads spread to a
width of 24 mm were vibrated in the width direction and formed into
a reinforcing-fiber sheet material having no gaps between the
reinforcing fiber multi-filament spread threads. The resulting
reinforcing-fiber sheet material had a width of about 310 mm and a
fiber weight of (fiber weight per unit area) about 40 g/m.sup.2.
(3) Using a powder-dispersing apparatus, copolymerized polyamide
resin powder, serving as a bonding thermoplastic-resin material,
was uniformly dispersed and deposited on a surface of a PEI resin
film, serving as a thermoplastic-resin sheet material. The amount
of dispersion was about 0.4 g/m.sup.2, which was about 1% of the
weight of the reinforcing fiber tows. (4) The thermoplastic-resin
sheet material, on which the bonding thermoplastic-resin material
is deposited, was continuously attached to a surface of the
resulting reinforcing-fiber sheet material, while being heated. At
this time, the heating temperature was controlled at about
150.degree. C. Release paper (produced by Lintec Corporation) was
fed together with the reinforcing-fiber sheet material. The
thermoplastic-resin-reinforced sheet material was attached to the
reinforcing-fiber sheet material at a speed of 10 m/min. (5) From
the resulting thermoplastic-resin-reinforced sheet material, sheets
having a size of 320 mm square in which, assuming that the fiber
direction was 0.degree. direction, fibers are arranged in 0.degree.
direction, 90.degree. direction, 45.degree. direction, and
-45.degree. direction were cut out and formed into a laminated
sheet material of
[(45.degree./0.degree./-45.degree./90.degree.).sub.3].sub.s. (6)
The laminated sheet material was placed on a flat CC composite
shaping mold having a thickness of 1 mm. A flat iron shaping mold
having a thickness of 1 mm was placed thereon, and another
laminated sheet material was placed thereon. After they are
alternately stacked into three-tier-structure, the peripheral
portions of the uppermost shaping mold and the lowermost shaping
mold were sealed with a seal member made of heat-resisting rubber
to form an airtight structure. A release sheet material
(thermosetting polyimide film, produced by UBE INDUSTRIES, LTD.,
thickness: 50 .mu.m) was provided between the laminated sheet
materials and the shaping molds. Then, the air in the shaping mold
was sucked (discharged) to bring the inside of the shaping mold
into a reduced pressure state of 10 Torr or less. (7) The shaping
molds accommodating the laminated sheet materials and inside of
which being in a reduced pressure state was placed in a hot press.
The shaping molds were placed on the lower mold of the hot press
mold preliminarily heated to 370.degree. C., then the upper mold of
the hot press mold was immediately lowered to apply pressure. At
this time, the mold surfaces of the upper mold and lower mold of
the hot press mold were flat such that they can fit the shaping
molds and apply pressure thereto. Hot pressing was performed at a
pressure of 2 MPa for 3 minutes. The air in the shaping molds was
continuously sucked (discharged) while the hot press was performing
hot pressing on the shaping molds, so as to maintain the inside of
the shaping molds in a reduced pressure state of 10 Torr or less.
(8) After the hot pressing, the shaping molds, the inside of which
was still in a reduced pressure state, were taken out of the hot
press and then placed in a cold press. The shaping molds were
placed on the lower mold of the cold press mold preliminarily
cooled to about 20.degree. by water cooling, and the upper mold of
the cold press mold was immediately lowered to apply pressure. At
this time, similarly to hot press mold, the mold surfaces of the
upper mold and lower mold of the cold press mold were flat such
that they can fit the shaping molds and apply pressure thereto.
Cold pressing was performed at a pressure of 2 MPa for 3 minutes.
The air in the shaping molds was continuously sucked (discharged)
while the cold press was performing cold pressing on the shaping
mold, so as to maintain the inside of the shaping molds in a
reduced pressure state of 10 Torr or less. (9) Then, the shaping
molds were taken out of the cold press. After the inside of the
shaping molds in a reduced pressure state was brought back to an
atmospheric pressure state, three thermoplastic-resin
composite-material moldings were obtained from the shaping
molds.
<Evaluation>
[0290] The resulting thermoplastic-resin composite-material
moldings were each finished as a flat molding having no warpage or
the like, having a thickness of about 0.9 mm and a fiber volume
content of about 60%. A part of the molding was cut and the cross
section was observed. As a result, it was confirmed that
impregnation of the thermoplastic resin into fiber tows, as well as
and the distribution of the carbon fibers, were excellent in spite
of the heat-resistant resin being used. In addition, high-quality
moldings were obtained under molding conditions in which the hot
pressing time was reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0291] FIG. 1 is a schematic view showing a multilayer
thermoplastic-resin-reinforced sheet material according to an
embodiment of the present invention.
[0292] FIG. 2 is a schematic view showing a wide
thermoplastic-resin-reinforced sheet material.
[0293] FIG. 3 is a schematic view showing another wide
thermoplastic-resin-reinforced sheet material.
[0294] FIG. 4 is a schematic view showing a
thermoplastic-resin-reinforced sheet material obtained by arranging
narrow thermoplastic-resin-reinforced sheet materials in a width
direction.
[0295] FIG. 5 is a schematic view showing another
thermoplastic-resin-reinforced sheet material used in an embodiment
of the present invention.
[0296] FIG. 6 is a schematic view showing another
thermoplastic-resin-reinforced sheet material used in an embodiment
of the present invention.
[0297] FIG. 7 is a schematic view showing a
thermoplastic-resin-reinforced sheet material obtained by arranging
another narrow thermoplastic-resin-reinforced sheet materials in
the width direction.
[0298] FIG. 8 is a schematic view showing a multilayer
thermoplastic-resin-reinforced sheet material in which
thermoplastic-resin-reinforced sheet materials are stacked and
bonded together.
[0299] FIG. 9 is an explanatory diagram related to a method for
producing a thermoplastic-resin-reinforced sheet material.
[0300] FIG. 10 is an explanatory diagram related to a method for
producing another thermoplastic-resin-reinforced sheet
material.
[0301] FIG. 11 is an explanatory diagram related to a method for
producing another thermoplastic-resin-reinforced sheet
material.
[0302] FIG. 12 is an explanatory diagram related to a method for
producing another thermoplastic-resin-reinforced sheet
material.
[0303] FIG. 13 is an explanatory diagram related to a method for
producing another thermoplastic-resin-reinforced sheet
material.
[0304] FIG. 14 is an explanatory diagram related to a method for
producing a multilayer thermoplastic-resin-reinforced sheet
material using a thermoplastic-resin-reinforced sheet material.
[0305] FIG. 15 is an explanatory diagram related to a method for
producing a plurality of narrow thermoplastic-resin-reinforced
sheet materials from a wide thermoplastic-resin-reinforced sheet
material.
[0306] FIG. 16 is an explanatory diagram related to a method for
producing a plurality of narrow thermoplastic-resin-reinforced
sheet materials from a wide thermoplastic-resin-reinforced sheet
material and winding them on bobbins.
[0307] FIG. 17 is an explanatory diagram related to a method for
producing a multilayer thermoplastic-resin-reinforced sheet
material from narrow thermoplastic-resin-reinforced sheet
materials.
[0308] FIG. 18 is an explanatory diagram related to a production
method in which a plurality of stacked
thermoplastic-resin-reinforced sheet materials are subjected to
heat and pressure to be bonded together.
[0309] FIG. 19 is an explanatory diagram related to surface shapes
of a heating roll.
[0310] FIG. 20 is an explanatory diagram related to a method for
producing thermoplastic-resin multilayer reinforced molding.
[0311] FIG. 21 is an explanatory diagram related to another method
for producing a thermoplastic-resin multilayer reinforced
molding.
[0312] FIG. 22 is a schematic cross-sectional view showing a state
in which a molding material is set in shaping molds.
[0313] FIG. 23 is a process explanatory diagram related to an
embodiment of the present invention.
[0314] FIG. 24 is a process explanatory diagram related to another
embodiment of the present invention.
[0315] FIG. 25 is a cross-sectional view showing a modification
related to attachment of a seal member in FIG. 23.
[0316] FIG. 26 is a process explanatory diagram related to yet
another embodiment of the present invention.
REFERENCE NUMERALS
[0317] A: thermoplastic-resin multilayer reinforced molding [0318]
B: preformed laminate [0319] S1, S2: multi-filament spread thread
[0320] 11, 12: multilayer thermoplastic-resin-reinforced sheet
material [0321] 21, 22: thermoplastic-resin-reinforced sheet
material [0322] 31, 32: reinforcing-fiber sheet material [0323] 41,
42: thermoplastic-resin sheet material [0324] 51: integration
thermoplastic-resin fiber tow [0325] 52: bonding
thermoplastic-resin material [0326] 61, 62: release film [0327] 90:
hot press molding apparatus [0328] 91: shaping upper metal mold
[0329] 92: shaping lower metal mold [0330] 93: flat upper metal
mold [0331] 94: flat lower metal mold [0332] 96: heating unit
[0333] 100, 101, 111: shaping mold [0334] 102: gas-discharging
space [0335] 103: hot press [0336] 106: cold press [0337] 109: tube
[0338] 110: seal member [0339] 200, 300:
thermoplastic-resin-reinforced sheet material producing apparatus
[0340] 400: sheet-type multilayer thermoplastic-resin-reinforced
sheet material producing apparatus [0341] 500: narrow
thermoplastic-resin-reinforced sheet material producing apparatus
[0342] 600: narrow-sheet-type multilayer
thermoplastic-resin-reinforced sheet material producing apparatus
[0343] 700: heat-integration mechanism
* * * * *