U.S. patent application number 10/175964 was filed with the patent office on 2003-10-02 for multi orientation composite material impregnated with non-liquid resin.
Invention is credited to Allman, Mike Glen, Ashton, Larry J., Kay, Rex W., Simpson, Craig B., White, Troy L..
Application Number | 20030186038 10/175964 |
Document ID | / |
Family ID | 29999055 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030186038 |
Kind Code |
A1 |
Ashton, Larry J. ; et
al. |
October 2, 2003 |
Multi orientation composite material impregnated with non-liquid
resin
Abstract
A composite material made of multiple filament bands is
disclosed. The filament bands are wound to create a composite
material. The filament bands may be impregnated with a solid or
semi-solid resin. The filament bands are wound in multiple
orientations to form a sheet of composite material. Additionally,
the composite material may be made to have a varying number of
layer and fiber orientations throughout the sheet of composite
material. In another embodiment, a composite component requiring
multiple layers and fiber orientations may be substantially
manufactured during a filament winding process.
Inventors: |
Ashton, Larry J.; (Mapleton,
UT) ; Simpson, Craig B.; (Mapleton, UT) ; Kay,
Rex W.; (Goshen, UT) ; White, Troy L.;
(Goshen, UT) ; Allman, Mike Glen; (Spanish Fork,
UT) |
Correspondence
Address: |
MADSON & METCALF
GATEWAY TOWER WEST
SUITE 900
15 WEST SOUTH TEMPLE
SALT LAKE CITY
UT
84101
|
Family ID: |
29999055 |
Appl. No.: |
10/175964 |
Filed: |
June 20, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10175964 |
Jun 20, 2002 |
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09443227 |
Nov 18, 1999 |
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6482497 |
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Current U.S.
Class: |
428/297.4 |
Current CPC
Class: |
B29L 2031/3085 20130101;
B29C 53/582 20130101; B29C 37/0064 20130101; B29C 70/543 20130101;
Y02T 50/40 20130101; B32B 37/0038 20130101; B29C 53/66 20130101;
B29C 70/202 20130101; B29C 53/8066 20130101; B29C 70/546 20130101;
D04H 3/12 20130101; Y10T 428/24994 20150401; B29C 70/32 20130101;
B29C 53/8016 20130101; D04H 3/04 20130101; D04H 3/07 20130101; B29C
70/44 20130101; B29C 70/443 20130101; Y02T 50/43 20130101; B64C
3/20 20130101; Y10T 428/24116 20150115 |
Class at
Publication: |
428/297.4 |
International
Class: |
D04H 003/00 |
Claims
What is claimed and desired to be secured by United States Letters
Patent is:
1. A composite material comprising: a plurality of filament bands,
wherein the individual bands are impregnated with a resin that is
solid or semi-solid at ambient temperatures, the composite material
having a plurality of layers of substantially parallel filament
bands, wherein alternating layer have intersecting orientations
with adjacent layers, such that the filament bands form a sheet of
composite material.
2. The material, as recited in claim 1, wherein the filament bands
are carbon fiber.
3. The material, as recited in claim 1, further comprising
additional layers of filament bands located on the sheet of
composite material.
4. The material, as recited in claim 3, wherein the filament bands
of the additional layers of filament bands are substantially
unidirectional.
5. The material, as recited in claim 1, wherein intersecting
orientations of the layers of filament bands create a plurality of
overlapping locations.
6. The material, as recited in claim 5, wherein an effective amount
of resin is present in the overlapping locations.
7. The material, as recited in claim 1, wherein the individual
filament bands are impregnated with substantially similar
quantities of resin.
8. The material, as recited in claim 1, wherein the material is
produced by winding the filament bands on a mandrel.
9. The material, as recited in claim 8, wherein the mandrel is a
drum.
10. The material, as recited in claim 1, wherein the intersecting
orientation of the filament bands have different angles from layer
to layer.
11. The material, as recited in claim 1, wherein the bands are at
least about 1 inch wide.
12. The material, as recited in claim 1, wherein the bands are no
more than about 0.5 inches wide.
13. The material, as recited in claim 1, wherein the material is
tacky.
14. The material, as recited in claim 1, wherein the layers of
filament band are substantially perpendicular to adjacent layers of
filament bands.
15. The material, as recited in claim 1, wherein the sheet of
composite material is substantially solid when cured.
16. The material, as recited in claim 1, further comprising a
removable backing attached to at least one side of the composite
material by the non-liquid resin.
17. A sheet of composite material comprising: a plurality of
filament bands, wherein the individual filament bands are
pre-impregnated with a resin that is solid or semi-solid at ambient
temperatures, the plurality of filament bands being wound into a
sheet of composite material, such that alternating layer of
filament bands have an intersecting orientation with adjacent
layers of filament bands, such that the filament bands form a sheet
of composite material.
18. The material, as recited in claim 17, wherein the filament
bands are wound on a mandrel.
19. The material, as recited in claim 18, wherein the mandrel is a
drum.
20. The material, as recited in claim 17, wherein the filament
bands are helically wound.
21. The material, as recited in claim 17, wherein the angle of
intersecting orientations are selected according to load
requirements of a selective component.
22. The material, as recited in claim 17, further comprising a
plurality of filament bands wound in a unidirectional orientation
wound onto the sheet of composite material.
23. The material, as recited in claim 17, wherein the material is
wound according to a design of a determined component.
24. The material, as recited in claim 17, wherein the material is a
pre-form.
25. The material, as recited in claim 17, wherein the filament
bands are a carbon fiber.
26. The material, as recited in claim 17, wherein the intersecting
orientation of the filament bands have at least three
orientations.
27. The material, as recited in claim 17, wherein the filament band
widths vary through the sheet.
28. The material, as recited in claim 17, wherein the filament
bands are impregnated with the resin while the filament bands are
being wound.
29. The material, as recited in claim 17, wherein the resin is
heated to impregnate the resin in the filament bands.
30. A process for manufacturing a composite material comprising:
pre-impregnating a first filament band with a resin that is solid
or semi-solid at ambient temperatures; winding the first filament
band at a first angle; pre-impregnating a second filament band with
a resin that is solid or semi-solid at ambient temperatures;
winding the second filament band in a second direction, wherein the
second angle has an intersecting orientation with the first angle,
such that the first filament band and the second filament band form
a composite material.
31. The process, as recited in claim 30, wherein the intersecting
orientation of the first angle and the second angle is
substantially perpendicular.
32. The process, as recited in claim 30, wherein the composite
material is wound on a rotating mandrel.
33. The process, as recited in claim 30, wherein the orientation of
the filament bands is controlled by a filament application section
of a filament winding machine.
34. The process, as recited in claim 33, wherein the application
section impregnates the filament bands with the resin.
35. The process, as recited in claim 30, wherein the first filament
band and the second filament band have a plurality of overlapping
locations.
36. The process, as recited in claim 35, wherein an effective
amount of resin is present in the overlapping locations.
37. The process, as recited in claim 30, wherein the first filament
band and the second filament band are impregnated with a
substantially similar quantity of resin.
38. A process for manufacturing a composite component comprising:
determining load requirement for the component; identifying the
number of layers and orientation of filament bands to meet load
requirements for the component; creating a manufacturing control
plan; and winding a plurality of filament bands on a mandrel,
wherein the plurality of filament bands are pre-impregnated with a
resin that is solid or semi-solid at ambient temperatures, the
plurality of filament bands being wound according to the
manufacturing control plan, such that the number of layers and
orientations of filament bands create a pre-form for the
component.
39. The process, as recited in claim 38, wherein the filament bands
are wound into a plurality of layers having at least three
different filament band orientations.
40. The process, as recited in claim 38, further comprising cutting
the pre-form from the composite material.
41. The process, as recited in claim 40, further comprising curing
the pre-form on a shape defining form.
42. The process, as recited in claim 38, wherein a plurality of
performs are simultaneously wound.
43. The process, as recited in claim 38, wherein the pre-form is
wound in a sheet of composite material.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part of co-pending
patent application Ser. No. 09/443,227 filed Nov. 18, 1999 and
entitled PRESSURE-CYCLED, PACKET-TRANSFERRED INFUSION OF
RESIN-STITCHED PREFORMS and is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to composite materials. More
particularly, the present invention relates to a composite material
having multiple resin impregnated filament bands.
[0004] 2. Technical Background
[0005] Filament winding and composite materials have been a
desirable substitute for metals and other materials in
manufacturing applications. Composite materials have the advantages
of being high strength, lightweight, and easily formable. Composite
materials are comprised of a fiber, typically carbon, that is
impregnated with a curable resin. Composite materials are often
drapable like a fabric, allowing the uncured composite material to
be formed into various shapes. Once the composite material is in
the desired shape, the resin is cured and hardened to create a
rigid structure.
[0006] Despite the many positive characteristics of composite
materials, the overall cost of composite materials often makes
their use impractical. Various factors affect the cost of composite
materials. One factor is the number of manufacturing steps required
in order to form a composite structure. Often manufacturing a
composite material and forming the composite material into the
desired shape requires multiple machines and extensive hand labor.
For example, one method of creating a composite material is to
weave fibers into a sheet of composite material. Weaving large
sheets of carbon fibers can require expensive machines and can be a
time intensive process.
[0007] Furthermore, impregnating a composite material with a resin
adds additional steps to the process. These additional steps can
involve impregnating entire sheets of composite materials with
resins, creating difficulties in uniformly applying a resin to a
large sheet of composite material. Additionally, these impregnating
processes are often performed by different manufacturers at
different locations, adding manufacturing and shipping costs at
each step. As a result, the overall price of the composite
materials for the end user can be high.
[0008] Another shortcoming of composite materials is the amount of
hand labor required when assembling a composite structure. Often,
multiple layers of composite materials are required in order to
make a structure, and different orientations of composite materials
are needed. In many current processes, each individual layer of
composite material is laid up and oriented by hand onto a form or
other shaping structure. The process of laying up and orienting
individual sheets of composite material can add further expense and
time to the already expensive and time-consuming manufacturing
process.
[0009] Yet another problem with current composite materials is the
handling of the resin impregnated composite material. In many
applications the resin is made to have a low viscosity in order to
allow resin to flow between the individual fibers of the material.
The resin may be provided in a liquid form at ambient temperatures.
While low viscosity resin allows for better permeation of the
composite material, a low viscosity of liquid resin creates
undesirable handling characteristics. Furthermore, the low
viscosity resin does not effectively maintain the lay up of the
composite sheet. Thus, the fibers may separate and fall apart when
being handled or transported. Also, a low viscosity resin may flow
away from certain sections of the composite material while being
cured, leaving some areas with insufficient resin.
[0010] Therefore, what is needed in the art is an inexpensive
composite material that eliminates the costs inherent in the
composite manufacturing process. It would be an advancement in the
art to provide a composite material impregnated with a resin that
is solid or semi-solid at ambient temperatures. It would also be an
advancement in the art to provide a composite material that is
manufacturable in multiple layers and with multiple fiber
orientations.
[0011] It would be another advancement in the art to provide a
process that eliminates manual assembly steps in forming composite
structures by creating a significant portion of a composite
structure while manufacturing the composite material. Furthermore,
it would be an advancement to provide a composite material that
prevents the resin from uncontrollably transferring to objects that
come in contact with the material or from flowing out of the
uncured composite material. It would be another advancement in the
art to provide a composite material with desirable tack and drape
characteristics for forming the composite material into a desired
shape. Such apparatuses and methods are disclosed and claimed
herein.
BRIEF SUMMARY OF THE INVENTION
[0012] The apparatus and method of the present invention have been
developed in response to the present state-of-the-art, and, in
particular, in response to problems and needs in the art that have
not yet been fully resolved by currently available airbag systems.
Thus, it is an overall objective of the present invention to
provide an inexpensive composite material that is formable and
capable of being rapidly manufactured.
[0013] The composite material may be comprised of a plurality of
layers of filament bands wound to define a composite sheet. The
composite bands may be made of any number of fibers, such as a
carbon fiber. The filament bands are impregnated with a resin that
is a solid or semi-solid at ambient temperatures. Ambient
temperatures may encompass temperatures that are found in a
manufacturing facility. The solid or semisolid resin may be heated
to a viscous state in order to impregnate the filament bands.
[0014] The layers of filament bands may have multiple filament
bands that are substantially parallel to one another. The layers of
filament bands may be positioned on one another where alternating
layers of filament bands have intersecting orientations. The
intersecting orientations of adjacent filament bands may be
substantially perpendicular to one another. Additional layers of
filament bands may be added to define further layers of filament
bands on a sheet of composite material.
[0015] The composite material may be wound onto a mandrel having
various shapes. The mandrel may be drum shaped or be a more complex
curved shape. In one winding application the composite material has
been helically wound on a mandrel. The winding may be accomplished
with a filament winding machine having a filament application
section with a resin dispensing apparatus.
[0016] The filament bands may be at least about 0.5 inches wide.
Other embodiments may include filament bands that are at least
about 1 inch wide, while other filament bands may be no more than
about 0.5 inches wide. The width and orientation of the individual
bands may also vary throughout a sheet of material.
[0017] Generally, the process for manufacturing a composite
material may be comprised of feeding a filament band from a
filament distribution apparatus onto a mandrel. As the filament
bands are being fed from the filament distribution apparatus, the
filament bands are impregnated with a resin that is solid or
semi-solid at ambient temperatures. Then the filament bands are
laid on the mandrel in selective orientations and in a selective
number of layers. The composite bands may be wrapped around a
removable backing to prevent the semi-solid or solid resin from
transferring to objects that come in contact with the material. The
backing may be removed when the composite material is being applied
to a form.
[0018] Multiple layers and orientations of the filament bands may
exist in a composite material according to load requirements for a
selected part or component, where the composite material is a
pre-form. A pre-form is a part made of composite material where the
features of the part are created during the winding process, thus
eliminating laying up multiple layers of composite sheets.
Different features in different locations of the parts may be
created by varying the orientation and number of layers of the
filament bands.
[0019] A pre-form may be manufactured by determining the load
requirements for a composite component. The load requirements are
based upon the design and the intended use of the component. Next,
the number of layers and orientation of the filament bands needed
in order to meet load requirements are identified. Then, a
manufacturing control plan is created. Finally, the filament bands
are wound according to the manufacturing control plan, laying the
filament bands in the orientations and the layers for the load
requirements of the component.
[0020] These and other features, and advantages of the present
invention will become more fully apparent from the following
description and appended claims, or may be learned by the practice
of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order that the manner in which the advantages and
features of the invention are obtained, a more detailed description
of the invention summarized above will be rendered by reference to
the appended drawings. Understanding that these drawings only
provide selected embodiments of the invention and are not therefore
to be considered limiting in scope, the invention will be described
and explained with additional specificity and detail through the
use of the accompanying drawings in which:
[0022] FIGS. 1A-H are top views of the process of manufacturing a
composite material.
[0023] FIG. 2 is a top view of a composite sheet manufactured with
in the scope of the present invention.
[0024] FIG. 3 is a cross-sectional view of the sheet of composite
material of FIG. 2.
[0025] FIG. 4 is a top view of a filament winding machine winding a
sheet of composite material within the scope of the present
invention.
[0026] FIG. 5 is a cross-sectional perspective view of a multilayer
composite material.
[0027] FIG. 6 is a pre-form manufacturing process flow diagram.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The preferred embodiments of the invention are now described
with reference to FIGS. 1-6, wherein like reference numbers
indicate identical or functionally similar elements. The present
invention, as generally described and illustrated in the Figures,
may have a wide variety of configurations. Thus, the following more
detailed description of the embodiments of the system and method of
the present invention, as represented in the Figures, is not
intended to limit the scope of the invention as claimed, but is
merely representative of presently preferred embodiments of the
invention.
[0029] The present invention includes a composite material
providing several advantages in the art of composite materials. The
composite material is relatively inexpensive and has a highly
controllable manufacturing process. The composite material also has
desirable drape and tack characteristics to allow for ease in
forming the non-cured composite material into a desired shape or
form. The composite material also provides for varying of the
material characteristics of the composite material during a single
line manufacturing process.
[0030] Referring now to FIGS. 1A-H, a process for manufacturing a
sheet of composite material is illustrated. A sheet of composite
material 100, shown completed in FIG. 1H, is manufactured with
multiple layers of filament bands 110 laid out in alternating
orientations. In one embodiment, a filament band 110 is comprised
of multiple strands of various fibrous materials. The materials may
include carbon fiber, fiberglass, Kevlar, silicon carbide, or other
fibrous materials. The filament bands 110 may include other smaller
bands of fibrous materials merged together to create a large or
wide filament band 110. Alternatively, multiple smaller bands of
varying composite materials may be used to create a large filament
band 110 made of multiple fibrous materials. Such a combination of
fibrous materials would create a filament band 110 that is
optimized to manifest material characteristics of the combined
fibrous materials.
[0031] Generally, an increased number of fibers in a band 110 will
correspond to an increased width or thickness of the filament band
110. The width and thickness of the filament band 110 of a fixed
number of fibrous strands may be controlled by processing the band
110 through a series of idler rods or tension controlling devices.
The idler rods or tension controlling devices may spread the
filament band 110 to create a wider thinner filament band 110.
[0032] The filament bands 110 may be wound into a composite
material 110 through various filament band 110 laying procedures.
FIGS. 1A-H illustrate one process of creating a composite material
100 through a filament winding or layering process.
[0033] The composite material 100 of FIG. 1 may be comprised of
multiple layers of filament bands 110 laid out on one another. An
individual layer may comprise multiple filament bands 110 that are
substantially parallel, where individual bands 110 are positioned
relative to one another at spaced distances. In FIGS. 1A-H, the
individual figures represent the placement of a layer of filament
bands 110.
[0034] FIG. 1A depicts a layer comprising two filament bands 110a
being placed on a surface 120 in a first orientation, where the
surface 120 may be a mandrel, drum, table, or other surface. In
FIG. 1A, the first orientation is shown as being vertical. However,
this orientation is only shown for illustrative purposes. The two
parallel filament bands 110a of the first layer are positioned at a
horizontal spaced distance 116. In the composite material 100,
illustrated in FIG. 1A, the vertical filament bands 110a have a
horizontal spaced distance 116 that is equal to the width of three
filament bands 110. In such an embodiment, three layers of filament
bands 110 placed side to side will be required to form a complete
sheet of composite material 100.
[0035] Once the first layer of filament bands 110a is placed on the
surface 120, a second layer of filament bands 110b is placed upon
the first layer of filament bands 110a. The filament bands 110b of
the second layer are also substantially parallel to one another and
are positioned at a vertical spaced distance 124. The vertical
spaced distance 124 of the second layer of filament bands 110b may
be equal to the horizontal spaced distance 116 of the first layer
of filament bands 110a. Alternatively, the vertical spaced distance
124 may be different than the horizontal spaced distance 116.
However, when the vertical spaced distance 124 and the horizontal
spaced distance 116 are the same, an equal number of layers in each
orientation can be used to create a uniform sheet of composite
material 100.
[0036] Furthermore, the spaced distance of any layer of the
filament bands 110 may vary within a single layer. For example, a
layer may comprise four filament bands (not shown) where three
spaced distances separate the four filament bands. The three spaced
distances might each be different within a single layer of filament
bands. Such an embodiment may be desirable where additional
filament bands are required to strengthen portions of the composite
material or in a pre-form application, which will be discussed
later.
[0037] Independent of the spaced distances 116, 124 of the filament
bands 110a, 110b, the second layer of filament bands 110b is placed
on the first layer of filament bands 110a. The second layer of
filament bands 110b is positioned on the first layer of filament
bands 110a such that the second layer of filament bands 110b has an
intersecting orientation with the first layer of filament bands
110a. The intersecting orientation of the first layer of filament
bands 110a and the second layer of filament bands 110b may have a
wide range of relative angles.
[0038] In FIG. 1B, the relative angles of the filament bands 110a
of the first layer to the filament bands 110b of the second layer
are at a 90.degree. offset. However, different relative angles
between alternating layers of filament bands 110 may be possible.
In one embodiment, the relative angle of the layers of filament
bands 110 is such that a single filament band 110b from the second
layer intersects and overlaps a majority of the filament bands 110a
from the first layer on a sheet of composite material 100.
[0039] For example, FIG. 1B illustrates an intersecting angle where
a single filament band 110b intersects all of the filament bands
110a of the first layer. However, if the relative intersecting
angle between the two layers of the filament bands 110a, 110b was
approximately 10.degree. or less, then a single filament band 110b
of the second layer may only intersect a single filament band 110a
from the first layer.
[0040] Referring now to FIG. 1C, a third layer of filament bands
110c is placed on top of the second layer of filament bands 110b.
The third layer of filament bands 110c is placed on top of the
second layer of filament bands 110b in an intersecting orientation.
The orientation of the third layer of filament bands 110c may be
substantially equal to the orientation of the first layer of
filament bands 110a. However, the filament bands 110c of the third
layer may be placed at a location on the surface 120 adjacent to
the filament bands 110a of the first layer, such as illustrated in
FIG. 1C.
[0041] Similarly, a fourth layer of filament bands 110d may be laid
on the third layer of filament bands 110c in the same orientation
as a second layer of filament bands 110b. Subsequent layers of
filament bands 110e, 110f, 110g, 110h may be placed on one another
in alternating orientations to form a sheet of composite material
100, as illustrated and FIG. 1H.
[0042] FIGS. 1A, C, E, G and Figures B, D, F, H show subsequent
layers of filament bands 110 having similar intersecting angles as
being placed adjacent to previously laid filament bands 110.
However, subsequent layers of filament bands 110 need not
necessarily be adjacent to previously laid layers of filament bands
110. Subsequent filament bands 110 may overlap previously laid
filament bands 110. Alternatively, subsequent filament bands 110
may have a gap between previously laid filament bands 110.
[0043] While the spacing between subsequent filament bands 110 may
vary, it may be preferred for subsequent filament bands 110 to
substantially align to previously laid filament bands 110 in a
sequential manner, such as illustrated in FIG. 1C. This embodiment
prevents openings or windows from forming in the sheet of composite
material 100.
[0044] Additionally, the alignment as illustrated in FIGS. 1A-H
provides for a uniform distribution of filament bands 110. By
providing filament bands 110 with uniformly spaced distances within
a single layer and between layers, a composite material 100 with a
substantially constant thickness may be provided. In the embodiment
illustrated in FIGS. 1A-H, the thickness of the composite material
100 is equal to the thickness of two of the filament bands 110.
This occurs because any given section of the surface 120 is covered
by only two filament bands 110 with different orientations.
[0045] This may be best understood by viewing an overlapping
location 122 indicated in FIG. 1B. The overlapping location 122 is
created by a filament band 110b of the second layer overlapping a
filament band 110a of the first layer. This overlapping location
122 has a thickness equal to the thickness of the two filament
bands 110a, 110b which comprise the overlapping location 122. By
viewing the subsequent FIGS. 1C-H, it can be seen that no further
filament bands 110c-h are placed upon the overlapping location 122.
For this embodiment, the same will be true for any other given
sections of the composite material 100, where each section of the
composite material 100 is comprised of two filament bands 110 with
different fiber orientations.
[0046] Multiple variations of the structure of the composite
material 100, other than that illustrated in FIG. 1, may be
achieved. For example, the orientations of the filament bands 110
in a single layer may also vary along the length of the composite
material 100. In FIG. 1A, the two filament bands 110a of the first
layer are illustrated as parallel to one another. However, the two
filament bands 110a of the first layer may have any number of
angled orientations relative to one another, such as if one
filament band 110 was vertical and a second band was at a
30.degree. offset. Similarly, the filament bands 110 in other
layers may vary in the same manner as has been described above.
[0047] Furthermore, the illustration of vertical filament bands
110a and horizontal filament bands 110b in FIGS. 1A-H are only one
embodiment of the orientation of filament bands 110 possible with
the composite material 100. The filament bands 110 may have
multiple other orientations, thicknesses, and layers depending upon
the desired structure of the composite material.
[0048] Another feature of the present composite material 100 is the
use of filament bands 110 impregnated with a resin before the sheet
of composite material 100 is manufactured. The individual filament
bands 110 may be pre-impregnated with a resin that is in a solid or
semi-solid state at ambient temperatures. In one embodiment, the
resin may remain solid at temperatures up to about 120.degree. F.
The resin may include different epoxies and hardeners, such as a
phenolics and bisphenols that become liquid at a temperature of
about 160.degree. F.
[0049] However, various other epoxies are presently available that
are solid or semi-solid at ambient temperatures and are suitable
for composite material 100 applications. Generally, the resin
should be selected such that the resin remains solid or semi-solid
at ambient conditions in which the composite material 100 will be
handled and assembled. The temperature range may include
temperatures that may be common in a manufacturing facility, where
ambient temperatures are between about 50.degree. F. to 110.degree.
F., and may preferably be about 70.degree. F.
[0050] Additionally, the resin should be selected such that the
resin remains in a solid or semi-solid state when the composite
material 100 comes in contact with items in a manufacturing
facility that are warmer than ambient air temperatures. For
example, tools, forms, and assembly surfaces may have increased
temperatures due to friction, radiant heat, or other factors.
[0051] The resin should also remain in a solid or semi-solid state
during transportation and shipping. Often, the shipping of
materials occurs in trucks or shipping containers without
temperature regulation systems. The temperatures within the trucks
and shipping containers can exceed 100.degree. F. If the resin
becomes a viscous liquid during transportation and shipping, resin
may flow out of the material, leaving some sections with an
inadequate quantity of resin. Therefore, the resin should be
selected such that the resin remains solid or semi-solid at these
relatively high temperatures.
[0052] By providing a resin that remains solid or semi-solid
through a large range of ambient temperatures, the impregnation of
resin within the fibers will remain substantially uniform. A
uniform impregnation of resin will prevent the creation of weakened
sections within the composite material 100 caused by an
insufficient quantity of resin.
[0053] In order to impregnate the filament bands 110 with a solid
or semi-solid resin, the resin must be placed in a state where it
can be easily impregnated into a filament band 110. In one
application, the resin that is provided in a solid or semi-solid
state at ambient temperatures is heated into a liquid or viscous
liquid state. The heated viscous resin may then be impregnated into
the individual filament bands 110. After the liquid resin is
impregnated into the filament bands 110 the resin cools into a
solid or semi-solid state.
[0054] The filament bands 110 may be comprised of multiple smaller
filament bands that are merged together to create a generally large
filament band 110. Either the large filament band 110 or the
smaller filament bands which make up the large filament band 110
may be impregnated. It may be advantageous to minimize the number
of fibers that are impregnated at a single time. By minimize the
number of fibers, each fiber may be more easily and uniformly
impregnated with the heated resin.
[0055] Impregnating the individual filament bands 110 with resin
before the filament bands 110 are formed into a sheet of composite
material 100 provides several manufacturing and design advantages.
One advantage is the ability to eliminate the step of impregnating
a completed sheet of composite material 100 or otherwise coating
the wound composite material 100 with the resin. Often,
impregnating an entire sheet of composite material requires a large
bath of liquid resin. A bath of liquid resin requires the use of a
large quantity of resin that is not used and that has a potential
of receiving contaminants. Also, immersing a sheet of composite
material into a liquid resin bath does not allow the quantity of
resin that is impregnated into the composite material 100 to be
controlled.
[0056] Impregnating the filament bands 110 with resin before they
are wound into a sheet of composite material 100 allows for the
application of a sufficient quantity of resin between the different
layers of the filament bands 110. During the assembly process of
the filament bands 110, layers of individual filament bands 110 are
generally laid upon one another, as illustrated in FIGS. 1A-H.
[0057] For example, in FIGS. 1A and 1B the second layer of filament
bands 110b is laid upon the first layer of filament bands 110a. By
laying the two layers of filament bands 110a, 110b on one another,
an overlapping location 122 is created. If the filament bands 110a,
110b are not pre-impregnated with the resin, an insufficient and
ineffective quantity of resin may be present between the filament
bands 110a, 110b of the two layers. However, filament bands 110
that are pre-impregnated with a resin will have an effective and
sufficient quantity of resin in the overlapping locations 122. An
effective quantity of resin is a quantity that is capable of
providing a uniform distribution of resin throughout the composite
material 100. By having an effective and sufficient quantity of
resin between the various layers, a stronger and more uniform
composite material 100 will be formed.
[0058] Another advantage of pre-impregnating the filament bands 110
with a resin, that is solid or semi-solid at ambient temperatures,
is the tacky characteristics of a solid or semisolid resin. The
tack of the resin will allow the individual filament bands 110 to
stick to one another. As was illustrated in FIGS. 1A-H, a sheet of
composite material 100 is comprised of multiple individual filament
bands 110 that are selectively positioned. The tack of the resin
impregnated filament bands 110 allows the filament bands 110 to
adhere together, to form a sheet of composite material 100 that may
be easily handled.
[0059] Furthermore, the individual filament bands 110 are comprised
of smaller quantities of fibers. The use of the tacky resin
prevents the individual filament bands 110 from separating into
numerous fibers. Thus, a generally large sheet of composite
material 100 may be formed without the need for weaving, sewing, or
otherwise holding the sheet of composite material 100 together.
[0060] The tack of the solid or semi-solid resin also provides
advantages when placing the composite material 110 onto a form to
be cured. Typically, a composite material 100 is formed by placing
a sheet of uncured composite material 100 on to a form to define a
shape. As the composite material 100 is cured, the composite
material 100 will maintain the shape of the form to which it is
attached. The tack allows the composite material 100 to adhere to
the form without the need for any attachment mechanisms to hold the
composite material 100 to the form.
[0061] Furthermore, the tack of the composite material 100 created
by the solid or semisolid resin allows the composite material 100
to easily attach to other pieces of composite material 100. Often,
a composite structure is created by joining multiple pieces of
composite material 100 together. The tack of the resin allows
separate pieces of composite material 100 to be adhered together,
such that proper contact is maintained during curing.
[0062] The amount of tack of the composite material 100 will depend
upon the type of solid or semi-solid resin used. The tack may also
be a function of the temperature of the resin in the composite
material 100. It may be preferable for the tack of a sheet of
composite material 100 be sufficient to maintain its own weight on
a vertical or inverted surface.
[0063] In order to provide convenience in shipping and handling of
the tacky composite material, a removable backing 130, as
illustrated in FIG. 2, may be added to the composite material 100.
A removable backing 130 may be a plastic or other similar type of
material that creates a buffer between the tacky resin and other
objects. The removable backing 130 may be placed on both sides of
the composite material 100 in order to prevent the tacky resin from
adhering to objects that the composite material 100 comes in
contact with. Also, the removable backing 130 prevents resin from
transferring to surrounding objects.
[0064] The removable backing 130 and the tack may provide a useful
combination of features when applying the composite material 100 to
a form. When applying the composite material 100 to a form, one
side of the removable backing 130 may be removed to expose the
tacky composite material 100. The composite material 100 may then
be handled by the side of the composite material having the
remaining removable backing 130. The exposed tacky composite
material 100 may be adhered to a form by pressing on the removable
backing 130 of the opposing side. Once the composite material 100
is in place, the second side of removable backing 130 may be peeled
off from the composite material 100.
[0065] Referring now to FIG. 3, a cross-sectional view of the sheet
of composite material 100 of FIG. 2 is illustrated. The
cross-sectional view shows multiple layers of filament bands 110a-h
forming a sheet of composite material 100. The composite material
100 has a uniform thickness equal to the thickness of two filament
bands 110. The uniform thickness creates a composite material 100
having a top layer 212 and a bottom layer 216. Both the top layer
212 and bottom layer 216 are made of filament bands 110 from
multiple layers.
[0066] The relative positioning and lengths of the multiple layers
of filament bands 110 provide significant strength advantages.
Composite materials 100 receive their strength by combining fibers
having a high tensile strength with a resin having a high
compression and bending resistance. While the resin can withstand a
substantial tensile force, it is preferable for the fibers to be
loaded with a tensile force instead of the resin. An optimally
designed composite material 100 will be configured such that the
fibers are substantially loaded with tensile forces and the resin
is substantially loaded with compressive and sheer forces. Thus,
features of the composite material 100 which do not optimally load
either the fibers or resin should be avoided.
[0067] One feature of the composite material 100 that maybe
desirable to avoid is the locations where the filament bands 110g
transition between the top layer 212 and the bottom layer 216. The
transitioning of the filament band 110g from the upper layer 212 to
a lower layer 216 is referred to as a crimping section 220.
[0068] For example, the filament band 110g of the seventh layer is
illustrated in FIG. 3. Viewing FIG. 3 from the right to left, the
filament band 110g of the seventh layer is located on the top layer
212 of the composite material 100. The filament band 110g of the
seventh layer is positioned on top of three filament bands 110b,
110d, 110f, of other layers. The filament band 110g of the seventh
layer then crimps under a filament band 110h of the eighth layer.
After crimping under the filament band 110h of the eighth layer,
the filament band 110g of the seventh layer transitions from the
bottom layer 216 to the top layer 212. The locations where the
filament band 110g transitions from the top layer 212 to the bottom
layer 216 and then back again to the top layer 212 creates two
crimping sections 220 at each transition location.
[0069] The crimping sections 220 introduce vacancies 224 into the
composite material 100 where the filament band 110 transitions
between the top layer 212 and the bottom layer 216. The resin that
is impregnated in the filament bands 110 may fill the vacancies 224
with resin. Thus, when the filament bands 110 are loaded with a
tensile force, a portion of the tensile force will be transferred
to the resin filled vacancies 224. Because the fibers of the
filament bands 110 are typically stronger than the resin, the resin
filled vacancies 224 may reduce the strength of the material
100.
[0070] While the crimping sections 220 may introduce vacancies 224
into the composite material 100, a selective amount of crimping
sections 220 provide some of advantages to the composite material
100. The crimping sections 220 allow the filament bands 110 of the
top layer 212 and the bottom layer 216 to intertwine. If the
composite material 100 is comprised of only two layers of filament
bands 110 with no crimping sections 220, then the strength of the
composite material 100 would only be equal to the strength of the
resin holding the two layers together. However, the selective use
of crimping sections 220 allows the top layer 212 and the bottom
layer 216 to be connected together by the filament bands 110.
[0071] The composite material 100 disclosed herein provides a
minimal number of crimping sections 220. As can be seen in FIG. 3,
the filament band 110g of the seventh layer is positioned
substantially on the top layer 212 with two small crimping sections
220. By providing the generally long sections of the filament bands
110 that are on a single layer of the composite material 100, a
tensile load on the filament bands 110 will be placed upon the
straight fibers of the filament band 110.
[0072] Referring back to FIG. 2, an inspection of the composite
material 100 illustrates that a majority of the filament bands 110
have straight sections of fiber without crimping sections that are
at least three times the width of the filament bands 110.
Additionally, selective filament bands 110 have no crimping
sections 220. While the ratio of length of the filament bands 110
to the width is noted for illustrative purposes only, it does
demonstrate the advantages of the composite material 100 in
maximizing the straight sections of filament bands 110, while still
employing a minimal number of crimping sections 220.
[0073] Methods for manufacturing the composite material 100 may
include filament winding as well as laying out the individual
filament bands 110. Referring now to FIG. 4, a filament winding
machine 310 is illustrated. The filament winding machine 310 is
provided to apply the filament bands 110 to a mandrel 316 or other
similar structure. The filament winding machine 310 is comprised of
a mandrel 316, a filament application section 320, and a transport
system 330.
[0074] The filament winding machine 310 is configured to wind
spools of fiber 326 on to a mandrel 316 to form a sheet of
composite material 100. The filament winding machine 310 may also
include a resin source 318 that provides a supply of resin to
impregnate the filament band 328 with a resin before the filament
band 328 is wound onto the mandrel 316. As mentioned previously,
the resin source 318 may be attached to a heating unit 322 in order
for the resin to be heated to a liquid state so that the resin may
be impregnated into the filament band 328.
[0075] The filament band 328 is wound onto a mandrel 316. The
mandrel 316 may be a large rotating drum or other similar device
that will allow the application of filament bands 328 that are
pre-impregnated with a resin. In one embodiment, the mandrel 316 is
configured to rotate about an axle 324, such that the mandrel 316
draws the filament band 328 from the filament application section
320.
[0076] The filament application section 320 may be comprised of one
or more filament sources, such as filament spools 326, to provide a
source of fibers in order to create the filament band 328. The
spools 326 may provide a source of filament fibers in order to
create a filament band 328, or alternatively the spools 326 may
provide multiple smaller filament bands that are merged into a
single large filament band 328.
[0077] The filament application section 320 may be configured to
translate relative to the mandrel 316. The translation may be
achieved by attaching the filament application section 320 to a
transport system 330. In one embodiment, the transport system 330
may be a track 332 on which the filament application section 320
may ride. One having ordinary skill in the art, will recognize that
multiple other systems may be provided to allow the filament
application section 320 to translate relative to the mandrel
316.
[0078] The spools 326 may be attached to the filament application
section 320, such that the spools 326 translate with the filament
application section 320. However, the spools 326 may be situated on
a stationary device, where the spools 326 feed the translating
filament application section 320 from the stationary location.
While attaching the spools 326 to the filament application section
320 may provide for a more simple feeding mechanism, the amount of
fiber that may be maintained on the spools 326 may be limited to a
small amount. Thus, in filament winding applications of large
sheets of composite material 100, it may be advantageous to provide
large quantities of fibers on spools 326 not attached to the
filament application section 320.
[0079] The motion of the filament application section 320 relative
to the mandrel 316 may be an automated or manual motion controlling
system. The motion controlling system may control the transitional
motion of the filament application section 320 as well as the angle
on which the filament band 328 is applied to the mandrel 316. While
both a manual and an automated system are possible, an automated
system may be the most practical for winding large sheets of
composite material 100.
[0080] The filament application section 320 may also include a
plurality of idler rods (not shown) which control the
characteristics of the filament band 328. For example, the idler
rods may place the filament band 328 in tension to change the width
of the filament band 328. A single filament band 328 may feed
through multiple idler rods before being applied to the mandrel
316.
[0081] Controlling the width of the filament band 328 provides
several advantages in the winding of a sheet of composite material
100. By widening a filament band 328, the thickness of the filament
band 328 may be reduced, and by providing a narrow filament band
328 the thickness may be increased. Thus, the thickness of the
filament band 328 may be controlled by a widening of the filament
band 328 through idler rods or other similar devices.
[0082] Another advantage in providing a generally wide filament
band 328 is the decreased manufacturing time needed to create a
sheet of composite material 100. A sheet of composite material 100
is formed by wrapping the filament band 328 around the mandrel 316
until the mandrel 316 is substantially covered. By using a wide
filament band 328, the number of rotations required to cover the
mandrel 316 may be reduced. In one embodiment, the filament band
328 may be 0.5 to 1.0 inch in width. However, other embodiments may
employ a filament band 328 that is less than 0.5 inches wide or
that is larger than 1 inch wide.
[0083] The application of the filament band 328 may also be
controlled by the filament winding head 336. The filament winding
head 336 may be configured to control the angle at which the
filament band 328 is applied to the mandrel 316. The filament
winding head 336 may be capable of varying the angle of the
filament bands 328, while winding a single layer of filament bands
328. The filament winding head 336 may include the idler rods as
well as a resin application system for impregnating the filament
bands 328 with a resin.
[0084] The varying control systems of the filament winding machine
310 allows for a large degree of control over the features and
characteristics of a sheet of composite material 100. Thus, a
single machine may be employed to create multiple embodiments of
the composite material 100.
[0085] The winding process may be accomplished by attaching an end
of the filament band 328 to a location on the mandrel 316, such as
the end 340. The filament band 328 may be attached to the mandrel
316 by an adhesive tape or by the tack of the pre-impregnated
filament band 328. Attaching the end of the filament band 328 to
the end 340 of the mandrel 316 may be useful in determining the
starting and stopping point for the winding process. However, the
end of the filament band 328 may be attached to any location on the
mandrel 316.
[0086] In a composite material 100 employing a removable backing
130, the removable backing 130 will first be mounted on the mandrel
316 before attaching the filament band 328 to the mandrel 316. In
this embodiment, the end of the filament band 328 would be attached
to the removable backing 130. By winding the filament bands 328 on
to the removable backing 130, the sheet of composite material 100
may be removed from the mandrel 316 with at least one side of the
composite material 100 covered with a removable backing 130.
[0087] Once the filament band 328 is attached to the mandrel 316,
the mandrel 316 may be rotated to draw the filament band 328 from
the filament application section 320. As the filament band 328 is
drawn from the filament application section 320, the transport
system 330 translates relative to the mandrel 316. By varying the
rotational speed of the mandrel 316 and the translation speed of
the transport system 330, the manner in which the filament band 328
is applied to the mandrel 316 may be controlled.
[0088] The control of the rotation of the mandrel 316 and the
translation of the transport system 330 can determine the spaced
distance, the angle of the filament band 328, the intersecting
angle of the different layers of filament bands, and the relative
position of the various layers. These features of the composite
material 100 may remain constant throughout a single sheet of
composite material 100 or may change throughout a single sheet of
composite material 100.
[0089] For example, the filament band 328 may be laid out at a
first angle or orientation during the initial winding passes around
the mandrel 316. The angle of the filament band 328 may then be
changed to a second angle during the central winding passes around
the mandrel 316. The angle of the filament band 328 may then
returned back to the angle during the initial rotations of the
filament band 328 around the mandrel 316.
[0090] The ability of the filament band 328 to change its angle
during a single pass across the mandrel 316 is possible due in part
to the tack of the composite material 100. The tack of the resin
will allow the filament band 328 to adhere to the mandrel 316 and
maintain the angle in which it was placed on the mandrel 316.
Furthermore, when the angle is abruptly changed, the tack of the
filament band 328 will prevent the previously laid section of
filament band 328 from conforming to the new angle of the filament
band 328.
[0091] Similarly, the spaced distance between the filament bands
328 may also be varied during manufacturing of the composite
material 100 in the same manner as the angle of the filament band
328. Additionally, the angle of the filament band 328 as well as
the spaced distance of the filament band 328 may be change from
layer to layer.
[0092] Referring now to FIG. 5, a section of multilayer composite
material 410 is illustrated. The multilayer composite material 410
has a varying number of layers across its length. The multilayer
composite material 410, may be similar to a composite material that
has been laid out by hand in different layers. However, the
composite material 100 illustrated in FIG. 2, is wound in
multilayer sections during a single winding process, and has a
varying number of layers across its length.
[0093] The varying number of layers may be achieved by applying
multiple layers of filament bands in differing orientations and at
different locations. The orientations and layers may be controlled
during the filament winding process on the mandrel 316, as
discussed above. For example, the filament winding machine 310 may
wind a first layer 416 comprising two groups of filament bands laid
out in different orientations, such as illustrated in FIG. 2. After
the first layer 416 is formed, portions of a second layer 420 may
be laid out on top of selected portions of the first layer 416,
such as is illustrated in FIG. 5.
[0094] In one embodiment, the orientation of the fibers of the
filament bands of the second layer 420 are in a different
orientation than the orientation of the filament bands in the first
layer 416. The difference in orientations may be desirable for the
second layer 420 to receive a load in a different direction than
would be desirable for the fibers in the first layer 416. Next, a
third layer 432 may be placed upon the second layer 420 to receive
a load in yet another direction.
[0095] Additionally, a top layer 436 may be placed upon the entire
piece of composite material 410. The top layer 436 may function to
provide even transitions between the single layer sections and the
multilayer sections of the composite material 410. Furthermore, the
angle and orientations of the fibers and the filament bands in the
three layers 416, 420, 432 may be in a substantially similar
direction. The number of layers in a composite material 410 will
depend upon the desired application. The use of multiple layers
having filament bands with different orientations allows a
composite material 410 to be designed for certain components
without the necessity of manually laying out multiple layers of
composite material.
[0096] One application for a multilayer composite material 410
having differently oriented fibers throughout the composite
material 410 is the manufacture of a pre-form. A pre-form is a
composite component or part where at least a portion of the
structure is manufactured during the manufacture of the sheets of
composite material 100. By creating piece of composite material
that has the layers and orientations of a ready-to-be cured
component, the process of hand laying multiple sheets of composite
materials can be avoided.
[0097] Currently, most composite materials are manufactured without
a view of the end product to be made of the composite material.
Typically, generic composite materials of different thicknesses,
strength characteristics, and fiber orientations are manufactured.
From the generic supply of composite materials, end products are
manufactured by laying up multiple layers of the manufactured
composite materials in the desired shape and layers. The process of
manually laying out composite materials adds to the cost of the
overall part.
[0098] In order to avoid manually laying up the composite materials
to form a component, the multiple layers of composite material may
be created on one another when the composite material is
manufactured. To accomplish this, the design of the component or
part must be known before the composite material is manufactured.
Referring now to FIG. 6, a flow diagram illustrating the steps in
creating a pre-form is shown.
[0099] First, the load requirements for the end part or component
are determined 510. The load required will depend upon the
application and the loads that are intended to be placed upon the
part. The part may require sections of increased thickness to
receive a large load or may require locations for attachment of
other components that cannot be created when the composite material
is being manufactured.
[0100] Once these load requirements are known, the number of layers
and orientations of the filament bands will be determined in order
to meet the specifications of the part 520. These design
considerations may be illustrated by referring back to FIG. 5. The
multilayer composite material 410 may be a pre-form where the load
requirements for the right side 424 are larger than the load
requirements for the left side 426.
[0101] Referring again to FIG. 6, once the number of layers and
fiber orientations are determined, a manufacturing control plan can
be created 530 to manufacture the pre-form. The manufacturing
control plan describes how the filament winding machine 310 will be
operated in order to create the desired number of layers and fiber
orientations. The manufacturing control plan may include rotational
speed of the mandrel 316 with corresponding positions and speeds of
the filament application section 320. This control plan may be a
text plan for a machine operator or may be a computer program that
interfaces with an automated filament winding machine 310.
[0102] Once the manufacturing control plan is established, the
filament bands are wound on the mandrel 316 where the multiple
layers and fiber orientations create the pre-form 540. The
multilayer composite sheet 410 may then be cut into the shape of
the part where it is ready to be applied to a form and cured.
[0103] It is envisioned in the present application, that an
automated process for designing pre-forms may be established. The
automated process may receive the design parameters for a component
or part in a digital medium with associated load requirements, such
as a finite element analysis program. A computer program may then
determine the type of composite material, width of the filament
band, and type of resin. Next, the number of layers of the
composite material and the orientations of the layers may be
established for the part.
[0104] The computer program may then determine a manufacturing
control plan for interfacing with a filament winding machine to
manufacture a pre-form. An automated process may then control the
operational parameters of the filament winding machine. While any
one of the steps could be replaced with a manual process, an
automated process will generally be more efficient and cost
effective.
[0105] The composite material described in this application may
have multiple embodiments for manufacturing various composite
parts. Generally, the composite material may be described as a
plurality of layers of filament bands that are pre-impregnated with
a solid or semi-solid resin at ambient temperatures. The different
layers of filament bands have intersecting orientations relative to
one another. The resin may provide an amount of tack allowing the
composite material to easily be adhered to a form and to hold the
multiple filament bands together.
[0106] The present invention may be embodied in other specific
forms without departing from its structures, methods, or other
essential characteristics as broadly described herein and claimed
hereinafter. The described embodiments are to be considered in all
respects only as illustrative, and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims,
rather than by the foregoing description. All changes that come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *