U.S. patent application number 09/865568 was filed with the patent office on 2001-09-20 for apparatus for forming pattern onto article during injection molding.
This patent application is currently assigned to DAI NIPPON PRINTING CO., LTD.. Invention is credited to Atake, Hiroyuki, Hanamoto, Keiji, Kobayashi, Kazuhisa, Matano, Takashi, Miyazawa, Kazushi, Oono, Shinpei, Tarutani, Takashi.
Application Number | 20010022412 09/865568 |
Document ID | / |
Family ID | 13898863 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010022412 |
Kind Code |
A1 |
Oono, Shinpei ; et
al. |
September 20, 2001 |
Apparatus for forming pattern onto article during injection
molding
Abstract
In the method, after the pattern-bearing film is fed to the
female mold, the distal end of the film is fixed under a lower
portion of the female mold, and at the same time the film is
retreated by a force from the film supply portion. Thus, this
tightens up the film so that the slacks or wrinkles cannot be
formed on the film. Therefore, the film can be fortunately spread
around the parting surface of the female mold. In the apparatus,
the film suppressing frame is pressed to the female mold through
the sliding rod arranged in the female mold, in such a manner that
the female mold embraces the frame. Thus, the pressing of the frame
is performed by a simple structure, and the film is accurately
positioned to the internal surface of the female mold. Also, the
film suppressing frame is constituted to advance from and retreat
to the female mold. Thus, this causes a space between the both
molds and an outside standby position to be useless. A space around
the apparatus can be effectively utilized.
Inventors: |
Oono, Shinpei; (Tokyo-To,
JP) ; Miyazawa, Kazushi; (Tokyo-To, JP) ;
Hanamoto, Keiji; (Tokyo-To, JP) ; Tarutani,
Takashi; (Tokyo-To, JP) ; Matano, Takashi;
(Tokyo-To, JP) ; Kobayashi, Kazuhisa; (Tokyo-To,
JP) ; Atake, Hiroyuki; (Tokyo-To, JP) |
Correspondence
Address: |
PARKHURST & WENDEL, L.L.P.
Suite 210
1421 Prince Street
Alexandria
VA
22314-2805
US
|
Assignee: |
DAI NIPPON PRINTING CO.,
LTD.
|
Family ID: |
13898863 |
Appl. No.: |
09/865568 |
Filed: |
May 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09865568 |
May 29, 2001 |
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09263817 |
Mar 8, 1999 |
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6270331 |
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09263817 |
Mar 8, 1999 |
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08429218 |
Apr 25, 1995 |
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5925302 |
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Current U.S.
Class: |
264/267 ;
425/112 |
Current CPC
Class: |
B29C 2045/14213
20130101; Y10S 425/048 20130101; B29C 2045/14286 20130101; Y10S
425/221 20130101; B29C 45/1418 20130101 |
Class at
Publication: |
264/267 ;
425/112 |
International
Class: |
B29C 031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 1994 |
JP |
86870/1994 |
Claims
What is claimed is:
1. In a method for forming a pattern onto an article during an
injection molding thereof, comprising the steps of: feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating said pattern-bering film by a
heating board so as to soften it, said heating board having a
heating surface and being movable into and away from a space
between said male mold and said female mold; transferring said
pattern-bearing film to an internal surface of said female mold so
as to contact said pattern-bearing film with said internal surface;
causing said male mold and said female mold with said
pattern-bearing film therein to approach each other to form a
closed molding cavity; and injecting a molten resin into said
cavity to form a molded article to adhere said pattern-bearing film
to the surface of said article, the improvement comprising the step
of: feeding the pattern-bearing film from a film supplying section
to a position which is opposed to the internal surface of the
female mold; fixing a distal end of the pattern-bearing film by a
film fixing frame arranged at a downstream-side of the female mold
along the film feeding direction; retreating the pattern-bearing
film to the film supplying section so as to tighten up the
pattern-bearing film; and fixing the pattern-bearing film on the
parting surface of the female mold, whereby the heating board is
moved into a position where the heating surface thereof is opposed
to the pattern-bearing film fixed on the parting surface, and then
the pattern-bearing film is softened by the heating surface of the
heating board means.
2. In an apparatus for forming a pattern onto an article during an
injection molding thereof, comprising: means for feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating board means for heating said
pattern-bering film so as to soften it, said heating board means
having a heating surface and being movable into and away from a
space between said male mold and said female mold; means for
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; means for causing said male mold and said
female mold with said pattern-bearing film therein to approach each
other to form a closed molding cavity; and resin injecting means
for injecting a molten resin into said cavity to form a molded
article to adhere said pattern-bearing film to the surface of said
article, the improvement comprising: a film suppressing frame for
fixing said peripheral portion of said pattern-bearing film which
has fed by said feed means; fitting groove means, defined on the
periphery of a parting surface of said female mold, for holding the
film suppressing frame; and a sliding rod, slidably supported
within a through-hole formed in the female mold and extended
through the parting surface thereof, for moving the film
suppressing frame so that the film suppressing frame is pressed
into the fitting groove means with the pattern-bearing film
interposed therebetween, whereby the heating board is moved into a
position where the heating surface thereof is opposed to the
pattern-bearing film fixed on the parting surface, and then the
pattern-bearing film is softened by the heating surface of the
heating board means.
3. In an apparatus for forming a pattern onto an article during an
injection molding thereof, comprising: means for feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating board means for heating said
pattern-bering film so as to soften it, said heating board means
having a heating surface and being movable into and away from a
space between said male mold and said female mold; means for
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; means for causing said male mold and said
female mold with said pattern-bearing film therein to approach each
other to form a closed molding cavity; and resin injecting means
for injecting a molten resin into said cavity to form a molded
article to adhere said pattern-bearing film to the surface of said
article, the improvement comprising: a pair of holding members,
arranged on both sides of the female mold, for holding the heating
board means so as to-be opposed to the parting surface of the
female mold, the holding members being movable along a direction
connecting the male and female molds so as to press the heating
board means to the female mold.
4. In an apparatus for forming a pattern onto an article during an
injection molding thereof, comprising: means for feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating board means for heating said
pattern-bering film so as to soften it, said heating board means
having a heating surface and being movable into and away from a
space between said male mold and said female mold; means for
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; means for causing said male mold and said
female mold with said pattern-bearing film therein to approach each
other to form a closed molding cavity; and resin injecting means
for injecting a molten resin into said cavity to form a molded
article to adhere said pattern-bearing film to the surface of said
article, the improvement wherein said heating board means is
divided into a plurality of blocks, and each block independently
controlling the amount of the heat generated by the block.
5. In an apparatus for forming a pattern onto an article during an
injection molding thereof, comprising: means for feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating board means for heating said
pattern-bering film so as to soften it, said heating board means
having a heating surface and being movable into and away from a
space between said male mold and said female mold; means for
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; means for causing said male mold and said
female mold with said pattern-bearing film therein to approach each
other to form a closed molding cavity; and resin injecting means
for injecting a molten resin into said cavity to form a molded
article to adhere said pattern-bearing film to the surface of said
article, the improvement comprising: insulation board means for
covering the entire heating surface of the heating board means when
the heating board means is waiting at a standby position defined
apart from the space between the male and female molds.
6. In an apparatus for forming a pattern onto an article during an
injection molding thereof, comprising: means for feeding a
pattern-bearing film to a molding position where a male mold and a
female mold are opposed; heating board means for heating said
pattern-bering film so as to soften it, said heating board means
having a heating surface and being movable into and away from a
space between said male mold and said female mold; means for
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; means for causing said male mold and said
female mold with said pattern-bearing film therein to approach each
other to form a closed molding cavity; and resin injecting means
for injecting a molten resin into said cavity to form a molded
article to adhere said pattern-bearing film to the surface of said
article, the improvement comprising: heating wire means, arranged
at the upstream-side of the female mold along the film feeding
direction, for heating the pattern-bearing film so as to cut it
into a proceeding portion and a following portion thereof when the
heating board means is pressed into the parting surface of the
female mold.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for forming a
pattern onto an article during an injection molding thereof and an
apparatus for the same, for preventing impressions of a heating
board from remaining on the surface of the molded article or
molding
[0003] 2. Description of the Related Art
[0004] Conventionally, as decorative patterning methods for
three-dimensional solid moldings, a laminate method and a transfer
printing method are known In the laminate method, after a film on
which a pattern has been printed is shaped or concurrently
therewith, the film is adhered to a substrate, or while or after
the film is shaped, the film is filled with a resin. On the other
hand, in the transfer printing method, only a pattern ink of a film
on which the pattern has been printed is transferred to a molded
article or molding.
[0005] As a transfer printing method, a method disclosed in
Japanese Patent Laid-Open Publication Serial No. SHO 62-196113,
published on Aug. 29, 1987 is known. In this method, as will be
described later, a heating board which sucks a pattern-bearing film
thereon is moved into a space between a male mold and a female mold
which are spaced apart from each other by a predetermined distance.
Then the pattern-bearing film heated by the heating board is vacuum
sucked to the inner surface of the female mold. Thereafter, the
heating board is retreated to the outside of the space between the
male mold and the female mold. Next, the male mold and the female
mold are clamped or closed. In the cavity defined by these molds, a
molten resin is injected to form a molded article. Thus, the
pattern-bearing film is attached to the surface of the molded resin
article.
[0006] In this method, however, when the pattern-bearing film is
sucked to the heating board, air is caught between the heating
board and the pattern-bearing film. This air remains as air bubbles
so that the pattern-bearing film is not uniformly heated. In
addition, marks or impressions of vacuum holes defined on the
heating board remain on the surface of the final molding having the
pattern-bearing film sucked thereby. Thus, the appearance of the
molding is adversely affected.
[0007] To solve this problem, a method as disclosed in Japanese
Patent Laid-Open Publication Serial No. HEI 5-301250 (i.e.,
Japanese Patent Application Serial No. HEI 4-108271) has been
proposed. In this method, a square-shaped holding flame is
protruded from a peripheral edge of the heating surface of the
heating board so as to contact with the pattern-bearing film, and a
concave portion is formed at the inside of the annular holding
frame. When the pattern-bearing film is located to be opposed to
the heating board in order to heating the film, the concave portion
prevents the film from directly contact with the heating surface of
the heating board. Thus, the concave portion restrains the marks or
impressions of vacuum holes from being formed on the surface of the
final molding so that the appearance of the molding is fortunately
affected.
[0008] In the above method, however, while the pattern-bearing film
is heated by the heating board so as to be softened, the film is
transferred into the internal surface of the female mold so as to
be positioned thereto. At this state, slacks or wrinkles are liable
to be formed on the film and the positioning of the film cannot be
accurately performed by the effect of the softened film.
SUMMARY OF THE INVENTION
[0009] The present invention is made from the above-mentioned point
of view. A first object of the present invention is to provide a
method for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which the
pattern-bearing film can be transferred to a position opposed to
the internal surface of the female mold under the condition that
the slacks or wrinkles are not formed on the film, so that the
pattern-bearing film can be accurately positioned to the internal
surface of the female mold.
[0010] A second object of the present invention is to provide an
apparatus for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which the heating
board can be simply and securely pressed into the female mold.
[0011] A third object of the present invention is to provide an
apparatus for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which the heating
board can be securely pressed into the parting surface of the
female mold.
[0012] A fourth object of the present invention is to provide an
apparatus for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which the heating
board can uniformly heat the entire pattern-bearing film.
[0013] A fifth object of the present invention is to provide an
apparatus for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which a
insulation board waiting at a standby position can prevent the
pattern-bearing film or the like from being heated and deformed in
the standby position.
[0014] A sixth object of the present invention is to provide an
apparatus for forming a pattern onto an article during an injection
molding thereof and an apparatus for the same, in which the
pattern-bearing film can be cut by a simple structure and the
cutting is lower in cost.
[0015] According to one aspect of the present invention, the first
object is accomplished by a method for forming a pattern onto an
article during an injection molding thereof, comprising the steps
of: feeding a pattern-bearing film to a molding position where a
male mold and a female mold are opposed; heating said
pattern-bering film by a heating board so as to soften it, said
heating board having a heating surface and being movable into and
away from a space between said male mold and said female mold;
transferring said pattern-bearing film to an internal surface of
said female mold so as to contact said pattern-bearing film with
said internal surface; causing said male mold and said female mold
with said pattern-bearing film therein to approach each other to
form a closed molding cavity; and injecting a molten resin into
said cavity to form a molded article to adhere said pattern-bearing
film to the surface of said article, wherein the improvement
comprises the step of: feeding the pattern-bearing film from a film
supplying section to a position which is opposed to the internal
surface of the female mold; fixing a distal end of the
pattern-bearing film by a film fixing frame arranged at a
downstream-side of the female mold along the film feeding
direction; retreating the pattern-bearing film to the film
supplying section so as to tighten up the pattern-bearing film; and
fixing the pattern-bearing film on the parting surface of the
female mold, whereby the heating board is moved into a position
where the heating surface thereof is opposed to the pattern-bearing
film fixed on the parting surface, and then the pattern-bearing
film is softened by the heating surface of the heating board
means.
[0016] In the method, after the pattern-bearing film is fed to the
female mold, the distal end of the film is fixed under a lower
portion of the female mold, and at the same time the film is
retreated by a tensile force from the film supply portion. Thus,
this tightens up the film so that the slacks or wrinkles cannot be
formed on the film. Therefore, the film can be fortunately spread
around the parting surface of the female mold.
[0017] According to another aspect of the present invention, the
second object is accomplished by an apparatus for forming a pattern
onto an article during an injection molding thereof, comprising:
means for feeding a pattern-bearing film to a molding position
where a male mold and a female mold are opposed; heating board
means for heating said pattern-bering film so as to soften it, said
heating board means having a heating surface and being movable into
and away from a space between said male mold and said female mold;
means for transferring said pattern-bearing film to an internal
surface of said female mold so as to contact said pattern-bearing
film with said internal surface; means for causing said male mold
and said female mold with said pattern-bearing film therein to
approach each other to form a closed molding cavity; and resin
injecting means for injecting a molten resin into said cavity to
form a molded article to adhere said pattern-bearing film to the
surface of said article, wherein the improvement comprises: a film
suppressing frame for fixing said peripheral portion of said
pattern-bearing film which has fed by said feed means; fitting
groove means, defined on the periphery of a parting surface of said
female mold, for holding the film suppressing frame; and a sliding
rod, slidably supported within a through-hole formed in the female
mold and extended through the parting surface thereof, for moving
the film suppressing frame so that the film suppressing frame
is-pressed into the fitting groove means with the pattern-bearing
film interposed therebetween, whereby the heating board is moved
into a position where the heating surface thereof is opposed to the
pattern-bearing film fixed on the parting surface, and then the
pattern-bearing film is softened by the heating surface of the
heating board means.
[0018] In the apparatus, the film suppressing frame is pressed to
the female mold through the sliding rod arranged in the female
mold, in such a manner that the female mold embraces the frame.
Thus, the pressing of the frame is performed by a simple structure,
and the film is accurately positioned to the internal surface of
the female mold. Also, the film suppressing frame is constituted to
advance from and retreat to the female mold. Thus, this causes a
space between the both molds and an outside standby position to be
useless. A space around the apparatus can be effectively
utilized.
[0019] According to the other aspect of the present invention, the
third object is accomplished by an apparatus for forming a pattern
onto an article during an injection molding thereof, wherein the
improvement comprises: a pair of holding members, arranged on both
sides of the female mold, for holding the heating board means so as
to be opposed to the parting surface of the female mold, the
holding members being movable along a direction connecting the male
and female molds so as to press the heating board means to the
female mold.
[0020] In the apparatus, the heating board is held or surrounded by
the holding members provided on the female mold, in such a manner
that the female mold embraces the heating board. Thus, the heating
board is intensely pressed to the female mold. Even if the
compressed air is blown from the heating board at the vacuum
formation, the holding members prevent the heating board from being
apart from or removed from the female mold. The driving device can
be miniaturized, as compared that the heating board is pressed into
the female mold by means of a driving device disposed extremely
apart from the molds.
[0021] According to the other aspect of the present invention, the
fourth object is accomplished by an apparatus for forming a pattern
onto an article during an injection molding thereof, the
improvement wherein said heating board means is divided into a
plurality of blocks, and each block independently controlling the
amount of the heat generated by the block.
[0022] In the apparatus, each block independently controlling the
amount of the heat generated by the block. Thus, the temperature
distribution can be uniform.
[0023] According to the other aspect of the present invention, the
fifth object is accomplished by an apparatus for forming a pattern
onto an article during an injection molding thereof, wherein the
improvement comprises: insulation board means for covering the
entire heating surface of the heating board means when the heating
board means is waiting at a standby position defined apart from the
space between the male and female molds.
[0024] In the apparatus, the insulation board prevents the heat
radiated from the heating board from excessively heating the
pattern-bearing film before forming, the forming apparatus and so
forth, whereupon this restrains melting, deformation, fire and so
forth of the pattern-bearing film.
[0025] According to the other aspect of the present invention, the
sixth object is accomplished by an apparatus for forming a pattern
onto an article during an injection molding thereof, wherein the
improvement comprises: heating wire means, arranged at the
upstream-side of the female mold along the film feeding direction,
for heating the pattern-bearing film so as to cut it into a
proceeding portion and a following portion thereof when the heating
board means is pressed into the parting surface of the female
mold.
[0026] In the apparatus, when the heating board is pressed into the
parting surface of the female mold, the pattern-bearing film is
automatically cut by the heating wire. In addition, it is simple in
structure and is lower in cost.
[0027] Also, the pattern-bearing film opposed to the parting
surface of the female mold may be heated by the heating board in a
non-contact state. Alternatively, the pattern-bearing film opposed
to the parting surface of the female mold may be heated by the
heating board in a contact state.
[0028] These and other objects, features and advantages of the
present invention will become more apparent in light of the
following detailed description of best mode embodiments thereof, as
illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a side view schematically showing the overall
construction of an apparatus for forming a pattern onto an article
during an injection molding thereof according to a first embodiment
of the present invention;
[0030] FIG. 2 is a partial cross-sectional view of the heating
board shown in FIG. 1;
[0031] FIG. 3 is a front view of the heating board shown in FIG.
1;
[0032] FIG. 4 is a enlarged cross-sectional view showing the
heating board and the holding frame;
[0033] FIG. 5 is a side view showing the heating board and the film
suppressing frame;
[0034] FIG. 6 is a perspective view showing the film. suppressing
frame;
[0035] FIG. 7 is an explanation view showing a first step of the
operation according to the first embodiment;
[0036] FIG. 8 is an explanation view showing a step next to the
step of FIG. 7;
[0037] FIG. 9 is a side view of the female mold shown in FIG.
8;
[0038] FIG. 10 is an explanation view showing a step next to the
step of FIG. 8;
[0039] FIG. 11 is an explanation view showing a step next to the
step of FIG. 10;
[0040] FIG. 12 is an explanation view showing a step next to the
step of FIG. 11;
[0041] FIG. 13 is an explanation view showing a step next to the
step of FIG. 12;
[0042] FIG. 14 is an explanation view showing a step next to the
step of FIG. 13;
[0043] FIG. 15 is a side view schematically showing the overall
construction of an apparatus for forming a pattern onto an article
during an injection molding thereof according to a second
embodiment of the present invention;
[0044] FIG. 16 is a perspective view of the female mold shown in
FIG. 15;
[0045] FIG. 17 is an explanation view a first step of the operation
according to the second embodiment;
[0046] FIG. 18 is an explanation view a second step of the
operation according to the second embodiment;
[0047] FIG. 19 is an explanation view a third step of the operation
according to the second embodiment;
[0048] FIG. 20 is a cross-sectional view schematically showing the
overall construction of an apparatus for forming a pattern onto an
article during an injection molding thereof according to a third
embodiment of the present invention;
[0049] FIG. 21 is an explanation view a step of the operation
different from the step shown in FIG. 20;
[0050] FIG. 22 is a perspective view of the female mold shown in
FIG. 20;
[0051] FIG. 23 is a perspective view schematically showing the
construction of an apparatus for forming a pattern onto an article
during an injection molding thereof according to a fourth
embodiment of the present invention;
[0052] FIG. 24 is a side view of the male and female molds shown in
FIG. 23;
[0053] FIG. 25 is a side view of a modification of the heating
board; and
[0054] FIG. 26 is a cross-sectional view of the heating board shown
in FIG. 25.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] FIG. 1 is a side view schematically showing the overall
construction of an apparatus for forming a pattern onto an article
during an injection molding thereof. A male mold 1 is fixed on a
mounting board 3. The male mold 1 is opposed to a female mold 2. An
injection nozzle 5 is arranged on the male mold 1 to communicate
with an injection gate 4. The female mold 2 is fixed to a ram 7
through a movable board 6. With forward and backward traveling
operation of the ram 7, the female mold 2 advances to and retreats
from the male mold 1. In addition, the female mold 2 is provided
with an air exhaust hole 8 through which air in the female mold 2
is exhausted to the outside by a vacuum pump (not shown in the
figure). An fitting groove 1a in a shape of a rectangle is formed
on a parting surface of the male mold 1, and another fitting groove
2b in a shape of a rectangle is formed on a parting surface of the
female mold 2 so as to be opposed to the fitting groove 1a.
[0056] At a position spaced apart from the outer peripheries of the
male mold 1 and the female mold 2 by a predetermined distance, a
heating board 9 is disposed. The position where the heating board 9
is disposed will hereinafter be referred to as the standby
position. On the other hand, the position where the male mold 1 and
the female mold 2 are opposed and the heating board 9 is moved
therebetween will hereinafter be referred to as the loading
position. The heating board 9 can be laterally travelled between
the standby position and the loading position by a drive means (not
shown in the figure).
[0057] A pattern-bearing film X is drawn from a roll R in a
direction of an arrow shown in FIG. 1 by means of chuck devices 34
and 34 so that the film X is fed to a position opposed to the
female mold 2, as described in later.
[0058] FIGS. 2 and 3 show the construction of the heating board 9
in detail.
[0059] The heating board 9 has a stacked structure of a heating
plate 10, a liner plate 11, a heater panel 12, and an insulation
plate 13 which are stacked in this order. As described in later,
the heating plate 10 heats the pattern-bearing film X. A holding
frame 14 in a shape of a rectangle is provided on the front surface
of the heating plate 10. The heating board 9 is mounted to a
support member 15 so as to be moved by solenoids 16. With the
operation of the solenoids 16, the heating board 9 is moved in the
direction perpendicular to the pattern-bearing film X. The
solenoids 16 cause the heating board 9 to advance to and retreat
from the female mold 2.
[0060] The heating plate 10 of the board 9 is made of a metal with
high heat transfer characteristic. In the area where the heating
plate 10 is surrounded by a peripheral wall 14a of the holding
frame 14, a large number of small air blowing holes 17 are formed
in an array at intervals of a predetermined pitch. The air blowing
holes 17 pass from the front to rear surfaces of the heating plate
10. With the heating plate 10 and the peripheral wall 14a of the
holding frame 14, a recess 14b is formed as also shown in FIG. 5.
When a ceramic layer is formed on the front surface of the heating
plate 10, radiant heat efficiency will be improved. The liner plate
11, which is disposed behind the heating plate 10, is composed of a
metal plate with a high heat transfer characteristic. The liner
plate 11 has a surface which is in contact with the rear surface of
the heating plate 10. The surface has grooves 18 distributed
therein through which compressed air is supplied to the air blowing
holes 17. An air passageway 19 is provided at the center of the
liner plate 11. The air passageway 19 passes through the liner
plate 11. The air passageway 19 also passes through the center of
the heater panel 12 and the insulation plate 13. The air passageway
19 is open at the rear surface of the insulation plate 13. The open
portion of the air passageway 19 is connected to an air hose 20.
The air hose 20 can be connected to either a low pressure
compressor 22 or a high pressure compressor 23 by a three-way
switching valve 21.
[0061] The heater panel 12 has a number of heater wires 24. The
heater wires 24 are connected to a lead cable (not shown in the
figure) which supplies electricity. The insulation plate 13 serves
to effectively transfer the heat generated by the heater wires 24
toward the heating plate 10.
[0062] As shown in FIG. 3 and FIG. 4 (which is an enlarged view of
the portion denoted by symbol IV in FIG. 2), a seal ring receiving
groove 25 is formed along the peripheral wall 14a of the holding
frame 14. A seal ring 26 is fitted in the groove 25. With the seal
ring 26, air leakage can be prevented. In addition, in the vacuum
molding operation, the pattern-bearing film X can be prevented from
being deviated from a predetermined position.
[0063] As shown in FIGS. 1 and 2, at the standby position of the
heating board 9, a film suppressing device 31 is provided in
opposition thereto. The film suppressing device 31 includes a
square-shaped film suppressing frame 32 (shown in FIG. 6). The
suppressing frame 32 operates to suppress and hold the
pattern-bearing film X in a perfectly non-contact state. The film
suppressing device 31 has a chuck device 34 and a cutter device 35.
The chuck device 34 pulls the pattern-bearing film X to the
position between the heating board 9 and the film suppressing frame
32 while the film suppressing frame 32 is apart from the heating
board 9. The cutter device 35 cuts the pulled pattern-bearing film
X to have a predetermined size. The cutter device 35 is driven by
an air cylinder 36.
[0064] The pattern-bearing film X is initially in the form of a
strip on which particular patterns Y (see FIG. 3) are printed at
predetermined intervals. The pattern-bearing film X is wound in a
roll (R) shape and held on a supply and holding device S.
[0065] As an example of the "laminate film" for the above-mentioned
pattern-bearing film, a thermoplastic resin such as acrylic resin,
acrylonitrile-butadiene-stiyene copolymer (ABS), or polyvinyl
chloride with a pattern printed may be used.
[0066] As an example of the above-mentioned transfer printing film,
such a material may be used where a transfer printing layer
composed of a transparent protection layer, a pattern layer, and an
adhesive layer is formed over a releasable substrate film such as
biaxial stretching polyethylene terephthalate resin or
polypropylene.
[0067] From the viewpoint of the three-dimensional
contour-following characteristic (molding characteristic) required
in the process for injection-molding articles with simultaneous
forming of patterns and from the viewpoint of durability (such as
wearing resistance) of the surface of the pattern, "a resin which
will become a non-tacky thermoplastic solid even in a
non-crosslinked state after drying of the diluting solvent" may be
used. Such resin is disclosed in Japanese Patent Laid-Open
Publication Serial No. SHO 61-69487 and SHO 60-161121. An example
of the film substrate material of the laminate film or the
transparent protection layer of the transfer film is a substance
where a non-tacky thermoplastic copolymer such as acrylic resin
with a glass transition temperature of 0 to 250.degree. C. is added
with a polymerizable crosslinkable radical such as acryloyl radical
or meta-acryloyl radical.
[0068] The substance in a state before polymerization or
crosslinking is transferred or laminated to the surface of the
injected resin molding. Thereafter, with radiation of ultraviolet
rays or electric beam, the resultant laminate is crosslinked so
that it is hardened.
[0069] Now, with reference to FIGS. 7 to 14, an operation of the
apparatus will be described. The operation starts from a state of
FIG. 1, and then the chuck device 34 catches the end of the
pattern-bearing film X and pulls it across the male and female
molds 1 and 2 until it covers the entire cavity of the female mold
2, as shown in FIG. 7. The film suppressing frame 32 is moved from
the standby position disposed outside the region of the male mold 1
and the female mold 2 to a position opposed to the female mold 2
with the pattern-bearing film X therebetween as shown in FIG. 7.
Thereafter, the suppressing frame 32 is adjusted to coincide with
the fitting groove 2b on the parting surface of the female 2. The
groove 2b is defined so that it surrounds the cavity surface.
[0070] Next, as shown in FIG. 8, the film suppressing frame 32 is
pressed into the fitting groove 2b with the pattern-bearing film X
interposed therebetween. Thus, the pattern-bearing film X is
contacted to the parting surface of the female mold 2. At this
point, it is preferred that the outer surface of the film
suppressing frame 32 is level with the parting surface of the
female mold 2 after the fitting is completed. However, as shown in
the figure, when a groove 1a for fitting the film suppressing frame
32 is formed on the peripheral portion of the male mold 1 so that
it is opposed to the fitting groove 2b of the female mold 2, it is
not necessary to cause the outer surface of the film suppressing
frame 32 to be level with the parting surface Rather, the film
suppressing frame 32 may protrude so that a peripheral portion 14a
of the holding frame 14 can be easily pressed. FIG. 9 is a front
view of the female mold 2 seen from the left in FIG. 8. As shown in
FIG. 9, the film suppressing frame 32 has a connection portion 32
connected to a driving source disposed on the side thereof.
[0071] Next, as shown in FIG. 10, the heating board 9 at the
standby position is moved to the front surface of the female mold
2. Thereafter, by the peripheral wall 14a of the holding frame 14
on the heating board 9, the pattern-bearing film X is pressed
through the film suppressing frame 32. At this stage, the
pattern-bearing film X is brought in contact with the peripheral
wall 14a of the holding frame 14. Thus a closed heating space is
defined, and the pattern-bearing film X is heated in a non-contact
state. After the pattern-bearing film X is satisfactorily softened,
as shown in FIG. 11, it is subjected to a vacuum suction through
the air exhaust hole 8. When necessary, together with the vacuum
suction, an air may be blown toward the pattern-bearing film X
through the air blowing hole 17. Thus, the pattern-bearing film X
is caused to accord to the contour of the cavity surface 2a.
[0072] Thereafter, as shown in FIG. 12, the heating board 9 is
retreated to the standby position. Next, the female mold 1 and the
male mold 2 are clamped. A molten resin is injected from the
injection gate 4 so that the cavity is filled therewith.
[0073] After the molten resin is cooled and solidified, as shown in
FIG. 13, the male mold 1 and the female mold 2 are opened and then
the film suppressing frame 32 is separated from the film
suppressing frame fitting groove 2b on the female mold 2. Thus, a
final resin molding which is adhered to the pattern-bearing film X
is taken out. When the pattern bearing film X is a transfer
printing film, only the substrate film is peeled off with the
pattern being left on the final molding.
[0074] In another example of the method of opening the mold, after
the molten resin has been cooled and solidified, as shown in FIG.
14, the film suppressing frame 32 is moved from the fitting groove
2b of the female mold 2 into the fitting groove 1a of the male mold
1. After the pattern-bearing film X is released, the mold opening
operation shown in FIG. 13 may be performed. In this method, the
molding may be more easily taken out from the male mold 1 and the
female mold 2.
[0075] An effect intrinsic to the above-described embodiment is
that since the pattern-bearing film X is fixed directly on the
parting surface of the female mold and is thereafter heated and
softened, deformation and displacement seldom take place on the
pattern-bearing film X. In particular, when a pattern is to
positionally coincide with the mold, a high positional accuracy is
readily obtained. When the pattern is accurately positioned on the
convex and concave of the male and female molds, a positional mark
such as a cross-shaped letter is printed in advance on the
pattern-bearing film X, it is detected by a positional sensor such
as a photoelectric tube disposed on the apparatus, and then the
feeding of the pattern-bearing film X may be stopped depending on
the detected signal.
[0076] In the above-mentioned embodiment, the transfer printing
method was described. However, it should be noted that the present
invention may be applied to the laminate method.
[0077] In addition, in the embodiments, the panel heater which
radiates near-infrared rays was used. Besides such a heater, an
electric heater (which uses Nichrome coils and directly radiates
Joule's heat of surface resistor or the like to the pattern-bearing
film), a ceramic panel heater (which radiates far-infrared rays),
or dielectric heating may be used. Moreover, as an example of heat
transfer to the pattern-bearing film, radiant of infrared rays,
electromagnetic wave, or the like may be directly used.
Furthermore, air in the closed space may be heated so as to use
heat transfer thereof to the pattern-bearing film X. Of course,
both methods may be used.
[0078] With reference to FIGS. 15 to 19, a second embodiment of the
present invention will be described, and a driving structure of the
pattern-bearing film X is improved in the embodiment. As shown in
FIGS. 15 and 16, to the film suppressing frame 32 are fixed two
pairs of sliding rods 36, 36, 36 and 36 which are extended through
the female mold 2 and the movable board 6 and are connected to a
reciprocating mechanism (not shown) disposed behind the female mold
2. A film fixing frame 38 is arranged under the parting surface of
the female mold 2 so as to advance thereto and retreat therefrom as
shown by the arrow in FIG. 15. The film fixing frame 38 has a plate
extended in parallel to the lower plate of the film suppressing
frame 32, and the frame 38 at the both ends thereof is provided
with a pair of operating rods 39 and 39 which have a distance
therebetween being longer than the lateral distance of the
pattern-bearing film X. The operating rods 39 and 39 can be moved
by a reciprocating mechanism.40. On the other hand, a pair of
feeding rollers 42 and 42 which can positively and reversely rotate
are arranged at the downstream side of the film roll R supported on
the supply and holding device S. The feeding rollers 42 positively
rotate so as to feed the pattern-bearing film X toward the female
mold 2, while reversely rotate to feed the film X toward the roll
R.
[0079] In the embodiment, the female mold 2 is provided with a
large number of small air suction holes 8a which are communicated
with the cavity 2a and the air exhaust hole 8 so that the air in
the cavity 2a is sucked through the small air suction holes 8a and
the exhaust hole 8 to the outside. Insulation board 43 of thermal
insulation material is arranged in front of the heating board 9 and
can be moved by a driving device 44.
[0080] When the feeding roller 42 shown in FIG. 15 is positively
rotated and the chuck device 34 is activated, the pattern-bearing
film X is drawn until it covers the entire parting surface of the
female mold 2, as shown in FIG. 17. The state shown in FIG. 17
corresponds with that shown in FIG. 7 of the first embodiment.
Thus, the lower end of the pattern-bearing film X is moved to the
inside of the film fixing frame 38. In this state, however, a
little excess of the pattern-bearing film X is fed by the inertia
thereof so that slacks or wrinkles are formed in the film X, as
shown in FIG. 17. Therefore, as shown in FIG. 18, the film fixing
frame 38 is retreated by the reciprocating mechanism 40 through the
operating rods 39, so that the lower end of the film X is fixed by
the film fixing frame 38, and at the same time the feeding roller
42 is reversely rotated. Thus, the film X is tightened so that the
slacks or wrinkles can be removed. Thereafter, the sliding rods 36
are retreated, as shown in FIG. 19, so that the film suppressing
frame 32 is pressed into the fitting groove 2b with the film X
interposed therebetween. The state shown in FIG. 19 corresponds
with that shown in FIG. 8 of the first embodiment.
[0081] Processes after the state shown in FIG. 19 corresponds with
the processes shown in FIGS. 10 to 14, and a final resin molding on
which a pattern is formed during the injection is removed from the
molds. Also, in this embodiment, the insulation board 43 is located
opposite to the heating surface of the heating board 9 waiting on
the standby position shown in FIG. 15. Therefore, the insulation
board 43 prevents the heat radiated from the heating board 9 from
excessively heating the pattern-bearing film before forming, the
forming apparatus and so forth, whereupon this restrains melting,
deformation, fire and so forth of the pattern-bearing film.
[0082] Now, with reference to FIGS. 20 to 22, a third embodiment of
the present invention will be described. FIGS. 20 and 21 are
sectional views of the apparatus taken along a lateral line,
respectively. As shown in FIGS. 20 to 22, two pairs of members 50
for holding heating board 9 are arranged along the both sides of
the female mold 2 and the movable board 6 so as to advance thereto
and retreat therefrom. Each holding member 50 is formed in a shape
of U letter, and a pair of holding members 50 have a pair of
openings opposed to each other. Each holding member 50 is
reciprocated through a operating rod 53 driven by driving device 52
such as an air cylinder.
[0083] The pattern-bearing film X is fed so as to cover the entire
parting surface of the female mold 2, and then, as shown in FIG.
20, the film suppressing frame 32 is pressed into the fitting
groove 2b with the film X interposed therebetween, that is, the
film X is fixed in the same state as shown in FIG. 8. In this
state, the heating board 9 is advanced to the loading position
opposed to the female mold 2, and the holding members 50 are
located in a advanced position shown in FIGS. 20 and 22.
Thereafter, the heating board 9 is inserted into a space between a
pair of holding members 50. In order to facilitate the insertion, a
pair of holding members 50 should be located apart from each other
so as to hold both ends of the heating board 9, and should have a
internal distance so as to slidably accommodate the heating board
9.
[0084] In the state shown in FIG. 20, holding members 50 are
advanced to the left in FIG. 20 (a male direction ) by the driving
device 52, whereupon the heating board 9 is apart from the female
mold 2. In this state, the driving device 52 causes the operating
rods 53 to move to the right of FIG. 21, that is, a direction of
the arrow shown in FIG. 21. Thus, the heating board 9 held by the
holding members 50 are retreated to the female mold 2, and then
holding frame 14 disposed in front of the heating member 9 are
brought into contact with the film suppressing frame 32. When the
air in the cavity 2a is sucked through the exhaust hole 8, the
pattern-bearing film X which is spread around the openings of the
cavity 2a is sucked to the internal surface thereof. This state is
shown in FIG. 21. The processes after this state corresponds with
the processes of the first and second embodiments so that the
description thereof will be omitted.
[0085] According to the third embodiment, the heating board is held
or surrounded by the holding members provided on the female mold so
that the heating board is intensely pressed to the female mold.
Even if the compressed air is blown from the heating board at the
vacuum formation, the holding members prevent the heating board
from being apart from or removed from the female mold. The driving
device can be miniaturized, as compared that the heating board is
pressed into the female mold by means of a driving device disposed
extremely apart from the molds.
[0086] With reference to FIGS. 23 and 24, a fourth embodiment of
the present invention will be described. In the embodiment, the
heating board 9 is provided at upper surface thereof with a pair of
L-shaped supporting members 60 and 60. The distal ends of the
L-shaped supporting members 60 and 60 are extended toward the
female mold 2, and a heating wire 62 such as a Nichrome wire is
stretched between the distal ends thereof. Therefore, as shown in
FIG. 24, when the heating board 9 approaches the pattern-bearing
film X sucked to the parting surface of the female mold 2, the
heating wire 62 comes into contact with the pattern-bearing film X.
Therefore, the film X is heated by the wire 62 and is cut into a
proceeding portion and a following portion thereof. The cutting by
the heating wire is much simpler in structure and lower in cost, as
compared that the film is cut by a mechanically driven blade.
[0087] With reference to FIGS. 25 and 26, a modification of the
heating board will be described. The heating board is divided into
three pieces of heating blocks 9A, 9B and 9C along from the upper
to the lower in turn. Although it is divided into three pieces, the
number of the division may be purely optional. Electric heating
wires 24A, 24B and 24C whose temperatures are individually
controlled are laid within respective blocks 9A, 9B and 9C, and
temperature sensors 70A, 70B and 70c are respectively inserted into
three blocks 9A, 9B and 9C.
[0088] In case the heating wire is laid within the heating board so
that the temperature of the heating board is uniformly distributed,
the heating board constituted of one body has a tendency that the
higher the position of the heating board is, the higher the
temperature thereof is, whereupon the higher the position of the
pattern-bearing film to be heated is, the higher the temperature
thereof is. In the modification, however, as the heating board is
divided into a plurality of blocks along the longitudinal direction
and the temperatures of the respective blocks are individually
controlled by the sensors, this prevents the temperature of the
film from ununiformly distributing. The control of the temperature
may be depended on the prior art thereof. The decrease and the
increase of the amount of the heat generated by the wire can be
performed by the prior art controller such as a thyristor, a
bimetal, etc.
[0089] Although the present invention has been shown and described
with respect to best mode embodiments thereof, it should be
understood by those skilled in the art that the foregoing and
various other changes, omissions, and additions in the form and
detail thereof may be made therein without departing from the
spirit and scope of the present invention.
* * * * *