U.S. patent application number 13/881784 was filed with the patent office on 2013-08-29 for film-forming apparatus and film-forming method.
This patent application is currently assigned to 3M INNOVATIVE PROPERTIES COMPANY. The applicant listed for this patent is Hideki Serizawa, Takashi Takenouchi. Invention is credited to Hideki Serizawa, Takashi Takenouchi.
Application Number | 20130220539 13/881784 |
Document ID | / |
Family ID | 44908140 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130220539 |
Kind Code |
A1 |
Takenouchi; Takashi ; et
al. |
August 29, 2013 |
FILM-FORMING APPARATUS AND FILM-FORMING METHOD
Abstract
A film-forming apparatus (100) and method capable of film
lamination with superior evenness and good followability regardless
of the size, shape and number of articles being laminated. The
film-forming apparatus (100) provided has a first chamber (10, 11)
that is provided with a heating means (50, 51) and that is capable
of maintaining a vacuum or a pressurized state, a second chamber
(20, 21) that is disposed so as to be able to be joined to, and
separated from, the first chamber (10, 11), that is provided with a
movable supporting table (60, 61) on which an article (300, 310,
320) is supported and that is capable of maintaining a vacuum or a
pressurized state, a frame-like film holding member (30, 31) that
is disposed between the first chamber (10, 11) and the second
chamber (20, 21) and that holds a film (200, 210), and an auxiliary
film pressing tool (40, 41, 42) having a film pressing part (42a)
that inhibits lifting of the film (200, 210) when the film is
laminated on a surface of the article (300, 310, 320).
Inventors: |
Takenouchi; Takashi;
(Atsugi-shi, JP) ; Serizawa; Hideki; (Sunto-gun,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Takenouchi; Takashi
Serizawa; Hideki |
Atsugi-shi
Sunto-gun |
|
JP
JP |
|
|
Assignee: |
3M INNOVATIVE PROPERTIES
COMPANY
ST. PAUL
MN
|
Family ID: |
44908140 |
Appl. No.: |
13/881784 |
Filed: |
October 26, 2011 |
PCT Filed: |
October 26, 2011 |
PCT NO: |
PCT/US11/57825 |
371 Date: |
April 26, 2013 |
Current U.S.
Class: |
156/285 ;
156/382 |
Current CPC
Class: |
B29C 51/16 20130101;
B29C 2791/006 20130101; B29C 51/10 20130101; B32B 37/1009 20130101;
B29C 65/02 20130101 |
Class at
Publication: |
156/285 ;
156/382 |
International
Class: |
B29C 65/02 20060101
B29C065/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2010 |
JP |
2010-244511 |
Claims
1. A film-forming apparatus that laminates a film on a surface of
an article, said apparatus comprising: a first chamber having a
heating means and being capable of maintaining a vacuum or a
pressurized state; a second chamber that is disposed so as to be
able to be joined to, and separated from, the first chamber, that
is provided with a movable supporting table on which an article is
supported, and that is capable of maintaining a vacuum or a
pressurized state; a frame-like film holding member that is
disposed between the first chamber and the second chamber and that
holds a film; and an auxiliary film pressing tool having a film
pressing part that inhibits lifting of the film when the film is
laminated on the surface of the article, wherein the film pressing
part is disposed in a position corresponding to a gap zone between
articles in cases where a plurality of articles is supported on the
supporting table in the second chamber, and the auxiliary film
pressing tool is disposed in a removable manner.
2. The film-forming apparatus described in claim 1, wherein the
film pressing part of the auxiliary film pressing tool has a shape
and a disposition according to a region in which lifting of the
film occurs when laminating the film on the surface of a single
article or a plurality of articles without using this supporting
tool.
3. (canceled)
4. The film-forming apparatus described in claim 1, wherein the
film pressing part of the auxiliary film pressing tool comprises a
rod-like or band-like rigid member.
5. The film-forming apparatus described in claim 1, wherein the
auxiliary film pressing tool further comprises a pressure sensitive
adhesive layer on the surface that comes into contact with the film
when laminating the film on the surface of an article.
6. A film-forming apparatus that laminates a film on a surface of
an article, said apparatus comprising: a first chamber provided
with a heating means and being capable of maintaining a vacuum or a
pressurized state; a second chamber disposed so as to be able to be
joined to, and separated from, the first chamber, provided with a
movable supporting table on which a plurality of articles are
supported, and capable of maintaining a vacuum or a pressurized
state; a frame-like film holding member that is disposed between
the first chamber and the second chamber and that holds a film; and
an auxiliary film pressing tool attached to a bottom of the first
chamber or the film holding member and having a film pressing part
that inhibits lifting of the film when the film is laminated on a
surface of the article, wherein the film pressing part is disposed
in a position corresponding to a gap zone between articles in cases
where a plurality of articles is supported on the supporting table
in the second chamber, and the auxiliary film pressing tool is
disposed in a removable manner.
7. A method for film-forming, said method comprising: providing a
first chamber having a heating means and being capable of
maintaining a vacuum or a pressurized state; providing a second
chamber capable of maintaining a vacuum or a pressurized state, and
having a supporting table disposed therein; separating the first
chamber from the second chamber so as to obtain an open state at
atmospheric pressure; disposing a plurality of articles on the
supporting table in the second chamber; attaching an auxiliary film
pressing tool either to a bottom of the first chamber or between
the first chamber and the second chamber, with the auxiliary film
pressing tool being disposed in a removable manner and having a
film pressing part; disposing the film pressing part in a position
corresponding to a gap zone between articles; holding a film
between the first chamber and the second chamber; forming an
enclosed region in both the first chamber and the second chamber
with the film respectively; forming a vacuum in both the first
chamber and the second chamber; and pressurizing only the first
chamber to atmospheric pressure or higher, moving the supporting
table in the second chamber towards the first chamber, and
partially pressing the film by means of the pressure difference
between the chambers and the auxiliary film pressing tool so as to
laminate the film sheet on a surface of a single article or a
plurality of articles.
8. The film-forming apparatus described in claim 2, wherein the
film pressing part of the auxiliary film pressing tool comprises a
rod-like or band-like rigid member.
9. The film-forming apparatus described in claim 2, wherein the
auxiliary film pressing tool further comprises a pressure sensitive
adhesive layer on the surface that comes into contact with the film
when laminating the film on the surface of an article.
10. The film-forming apparatus described in claim 4, wherein the
auxiliary film pressing tool further comprises a pressure sensitive
adhesive layer on the surface that comes into contact with the film
when laminating the film on the surface of an article.
11. The film forming apparatus described in claim 1, wherein the
auxiliary film pressing tool is disposed in a removable manner so
that a suitable auxiliary film pressing tool can be attached for
each article used.
12. The film forming apparatus described in claim 6, wherein the
auxiliary film pressing tool is disposed in a removable manner so
that a suitable auxiliary film pressing tool can be attached for
each article used.
Description
FIELD OF INVENTION
[0001] The present invention relates to a film-forming apparatus
that laminates a film on a surface of an article such as a
three-dimensional component or substrate and also relates to a
method for forming a film by using this film-forming apparatus.
BACKGROUND
[0002] Attempts have been made to decorate surfaces of
three-dimensional components used in exterior and interior
components of automobiles and motorcycles, electronic components,
furniture, and so on or the surface of articles such as
three-dimensional substrates having a complex shape, such as shapes
that include protrusions and recesses on the surface, by laminating
with a colored (e.g., paint replacement) or designed plastic film
instead of using conventional decorations (e.g., liquid paint).
[0003] As methods for laminating a film on the surface of this type
of article, film lamination forming methods using vacuum forming
apparatuses are known. Japanese Unexamined Patent Application
Publication No. 2002-67137 describes the constitution of a vacuum
forming apparatus and the procedure for a method of laminating a
plastic sheet on a core material using this vacuum forming
apparatus. As disclosed in the Japanese Unexamined Patent
Application Publication No. 2002-67137, vacuum forming apparatuses
generally have an upper chamber and a lower chamber able to be
joined to and separated from each other, with a heater incorporated
into the upper chamber.
[0004] In a common lamination method using a vacuum forming
apparatus, an article on which a film is to be laminated is
supported in the lower chamber and a plastic film that is the
formed object is disposed between the upper chamber and the lower
chamber. Next, the upper chamber is lowered so that the upper and
lower chambers each form an enclosed region with the plastic film,
and the conditions inside the upper chamber and the lower chamber
are changed from atmospheric pressure to a vacuum state by means of
a vacuum pump. Thereafter, the plastic film is softened by being
heated by the heater in the upper chamber and air is introduced
into the upper chamber only. By creating a pressure difference
between the upper chamber and the lower chamber in this way, the
plastic film is laminated on the surface of the article in the
lower chamber.
SUMMARY OF THE INVENTION
[0005] Because film lamination methods using vacuum forming
apparatuses are good in terms of the followability of the film to
the shape of the surface of the article being laminated, articles
on which films are laminated include articles having a wide variety
of shapes, such as not only simple cubes and cubic or
semi-spherical components, but also ring-shaped and U-shaped
components and components having a combination of complex
shapes.
[0006] However, in cases where the surface of the article to be
laminated has protrusions and recesses having large differences in
elevation, the film cannot completely follow the shape of the
surface, meaning that lifting of the film can occur in some
parts.
[0007] In addition, it has become desirable in recent years to
increase production efficiency by supporting as many articles as
possible in one chamber so as to be able to laminate a large number
of articles simultaneously. However, when increasing the number of
articles in the chamber, it is essential to make the distance
between the articles as small as possible, but as this distance
becomes smaller, it is common for lifting of the film to occur due
to differences in elevation between articles, meaning that it can
be difficult to maintain satisfactory shape followability of the
film at the ends of the articles.
[0008] Therefore, one object of the present invention can include
providing a film-forming apparatus capable of film lamination with
superior evenness and good followability regardless of the size,
shape, and number of articles being laminated in a process for
laminating a film on an article using a vacuum forming apparatus,
and a film-forming method using this film-forming apparatus.
[0009] A film-forming apparatus according to an aspect of the
present invention has a first chamber that is provided with a
heating means and that is capable of maintaining a vacuum or a
pressurized state, a second chamber that is disposed so as to be
able to be joined to, and separated from, the first chamber, that
is provided with a movable supporting table on which an article is
supported, and that is capable of maintaining a vacuum or a
pressurized state, a frame-like film holding member that is
disposed between the first chamber and the second chamber that
holds a film, and an auxiliary film pressing tool having a film
pressing part that inhibits lifting of the film when the film is
laminated on the surface of the article.
[0010] An auxiliary film pressing tool according to another aspect
of the present invention is attached to a film-forming apparatus
having a first chamber that is provided with a heating means and
that is capable of maintaining a vacuum or a pressurized state, a
second chamber that is disposed so as to be able to be joined to,
and separated from, the first chamber, that is provided with a
movable supporting table on which an article is supported, and that
is capable of maintaining a vacuum or a pressurized state, and a
frame-like film holding member that is disposed between the first
chamber and the second chamber and that holds a film, and this
auxiliary film pressing tool is attached to a bottom of the first
chamber or the film holding member, and has a film pressing part
that inhibits lifting of the film when the film is laminated on the
surface of the article.
[0011] A film-forming method according to a further aspect of the
present invention has a step of separating a first chamber that is
provided with a heating means and that is capable of maintaining a
vacuum or a pressurized state from a second chamber that is capable
of maintaining a vacuum or a pressurized state, so as to obtain an
open state at atmospheric pressure, a step of attaching an
auxiliary film pressing tool either to a bottom of the first
chamber or between the first chamber and the second chamber, a step
of holding a film between the first chamber and the second chamber,
a step of forming independently an enclosed region in both the
first chamber and the second chamber with the film, a step of
forming a vacuum in both the first chamber and the second chamber,
and a step of pressurizing only the first chamber to atmospheric
pressure or higher, moving a supporting table in the second chamber
towards the first chamber, and partially pressing the film by means
of the pressure difference between the chambers and the auxiliary
film pressing tool so as to laminate the film on the surface of a
single article or a plurality of articles.
[0012] According to the film-forming apparatus, auxiliary film
pressing tool and film-forming method of the present invention, it
is possible to effectively inhibit lifting of the film by means of
the auxiliary film pressing tool and thereby increase the yield in
a process for laminating a film on an article using a vacuum
forming apparatus. In addition, it is possible to achieve film
lamination with superior evenness and good followability regardless
of the size of the chamber and the size, shape, and number of
articles being laminated. Furthermore, in cases where a plurality
of articles is supported in a chamber, because it is possible to
reduce the distance between the articles, it is possible to
increase the number of articles able to be placed in the chamber
and therefore further increase productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A and 1B show conceptual cross-sectional views of an
embodiment of the film-forming apparatus of the present
invention.
[0014] FIGS. 2A and 2B show perspective views of a film-forming
apparatus during each step to explain a film lamination process
using an embodiment of the film-forming apparatus of the present
invention.
[0015] FIGS. 3A and 3B show perspective views of a film-forming
apparatus during each step to explain a film lamination process
using an embodiment of the film-forming apparatus of the present
invention.
[0016] FIG. 4A is a diagram showing a state in which a film is
laminated on an article by using a film lamination process using an
embodiment of the film-forming apparatus of the present
invention.
[0017] FIG. 4B is a diagram showing a state in which a film is
laminated on an article by using a film lamination process using a
conventional film-forming apparatus without using an auxiliary film
pressing tool.
[0018] FIG. 5 is a plan view showing a state in which a plurality
of articles is arranged in an embodiment of the present
invention.
[0019] FIG. 6 is a flow chart showing an example of the process for
designing an embodiment of the auxiliary film pressing tool of the
present invention.
[0020] FIG. 7A is a perspective view showing a state in which a
film is laminated on a different type of article without using a
corresponding auxiliary film pressing tool in an embodiment of the
present invention.
[0021] FIG. 7B is a perspective view showing a state in which a
film is laminated on a different type of article using a
corresponding auxiliary film pressing tool in an embodiment of the
present invention.
[0022] FIG. 8A is a perspective view showing a state in which a
film is laminated on a different type of article without using a
corresponding auxiliary film pressing tool in an embodiment of the
present invention.
[0023] FIG. 8B is a perspective view showing a state in which a
film is laminated on a different type of article using a
corresponding auxiliary film pressing tool in an embodiment of the
present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] A mode of an embodiment of the present invention will now be
explained by referring to the drawings.
[0025] Conceptual cross-sectional views of a mode of an embodiment
of the film-forming apparatus of the present invention (called "the
present embodiment" hereinafter) are shown in FIG. 1A and FIG. 1B.
FIG. 1A shows the state of the film-forming apparatus when articles
are placed therein, and FIG. 1B shows the state of the film-forming
apparatus when a film is laminated on the articles.
[0026] As shown in these diagrams, the film-forming apparatus (100)
of the present embodiment has a first chamber (10) capable of
maintaining a vacuum or a pressurized state at atmospheric pressure
or higher and a second chamber (20). The first chamber (10) and the
second chamber (20) are disposed so as to face each other, at least
one of the chambers can be moved by an external driving mechanism,
and the chambers can be joined together so as to form an enclosed
state and separated from each so as to form an open state.
Moreover, the orientation of the first chamber (10) and the second
chamber (20) is not restricted. For example, the first chamber (10)
and the second chamber (20) may be disposed as an upper and a lower
chamber, as shown in FIG. 1A, or as a left and a right chamber.
[0027] A frame-like film holding member (30) is disposed between
the first chamber (10) and the second chamber (20), and a film
(200) to be laminated on articles (300) is held by this film
holding member (30).
[0028] A heating means (50) for heating the film (200) is provided
in the first chamber (10), and a supporting table (60) for
supporting the articles (300) is provided in the second chamber
(20). The supporting table (60) can be moved towards the first
chamber (10) so as to raise up the articles. If necessary, the
articles (300) are immobilized on pedestals (70) designed according
to the shape of the articles and are disposed on the pedestals (70)
and the supporting table (60).
[0029] One of the main features of a film-forming apparatus of the
present invention is the inclusion of an auxiliary film pressing
tool that comprises one or more film pressing parts. The auxiliary
film pressing tool can be integrated with, or removably attached
to, either the bottom of the first chamber or the film holding
member. When the film is laminated on an article, the auxiliary
film pressing tool inhibits lifting of those parts of the film
susceptible to lifting (i.e., those film parts that would lift if
not for the use of the tool) by having the film pressing part or
parts press the susceptible parts of the film against a support
surface (e.g., a support table) on which the article is disposed.
The auxiliary film pressing tool should have sufficient rigidity to
press the sheet-like film against the support surface.
[0030] The shape of the auxiliary film pressing tool is not
particularly limited and can be set according to the film lifting
condition and can depend on a variety of conditions such as, for
example, the size, shape, number, and inter-article distance of the
articles on which the film is to be laminated, the size of the film
being laminated, and the size of the chambers. For example, the
auxiliary film pressing tool can include a film pressing part in
the shape of a bar, rod, plate, pin, post, ridge, fin, etc
dimensioned as desired. It is possible to form a pressure sensitive
adhesive layer on the surface of the auxiliary film pressing tool
that comes into contact with the film. In such cases, the film is
adhesively supported on the auxiliary film pressing tool by the
pressure sensitive adhesive layer, and it is possible to inhibit
sagging in the central part of the film caused by the film's own
weight.
[0031] Here, one of the main features of the film-forming apparatus
(100) of the present embodiment is that an auxiliary film pressing
tool (40) is attached thereto. The auxiliary film pressing tool
(40) can be integrated with, or removably attached to, either the
bottom of the first chamber (10) or the film holding member (30).
When the film (200) is laminated on the articles (300), this
auxiliary film pressing tool (40) inhibits lifting of the film by
having a film pressing part that presses a part of the film
(200).
[0032] Moreover, "film lifting" or "lifting" of the film means a
state whereby, when a film is laminated on an article, the film
does not satisfactorily follow the surface of the article or the
shape of the pedestal and comes away from the surface of the
article. Because fin-like floating occurs on the article or the
surrounding pedestal or supporting table, in many cases this is
also referred to as "the occurrence of fins" in the present
specification.
[0033] As shown in FIG. 1A, if a plurality of articles (300) is
disposed on the supporting table (60) in the second chamber (20),
the film pressing part of the auxiliary film pressing tool (40) can
be disposed at a position corresponding to a gap between the
articles (300). The auxiliary film pressing tool (40) should be a
member having sufficient rigidity to press the sheet-like film
(200), and the shape of the auxiliary film pressing tool is not
particularly limited. The shape of the auxiliary film pressing tool
(40) is set according to the film lifting condition and on the
basis of a variety of conditions, such as the size, shape, number,
and inter-article distance of the articles (300) on which the film
(200) is to be laminated, the size of the film being laminated, and
the size of the chambers.
[0034] By using the auxiliary film pressing tool (40), it is
possible to inhibit film lifting and thereby enable film lamination
having a high degree evenness and of followability to the shape of
the surface of an article.
[0035] In addition, because the followability of the film generally
deteriorates as the distance between the articles decreases when a
plurality of articles is placed in the same chamber, lifting occurs
more easily, but by using the auxiliary film pressing tool (40), it
is possible to reduce the distance between articles. Because it is
possible to place a higher number of articles in the chamber, it is
possible to increase productivity.
[0036] It is possible to form a pressure sensitive adhesive layer
on the surface of the auxiliary film pressing tool (40) that comes
into contact with the film (200). In such cases, the film (200) is
adhesively supported on the auxiliary film pressing tool by the
pressure sensitive adhesive layer, and it is possible to inhibit
sagging in the central part of the film caused by the film's own
weight.
[0037] Moreover, it is possible to use a common commercially
available vacuum forming apparatus as a film-forming apparatus not
having an auxiliary film pressing tool. For example, it is possible
to use a vacuum forming machine manufactured by Fu-se Vacuum
Forming. The auxiliary film pressing tool can be attached to a
frame member having an opening and is provided on the bottom of the
first chamber of these vacuum forming apparatuses either
mechanically or by means of an adhesive or the like. This method of
attachment is not restricted. It is preferable to dispose the
auxiliary film pressing tool in a removable manner so that a
suitable auxiliary film pressing tool can be attached for each
article used.
[0038] A film-forming process using the film-forming apparatus of
the present embodiment will now be explained by referring to the
conceptual perspective views of the apparatus shown in FIGS. 2A
through 3B. Moreover, the diagrams show examples in which an
axially shaped auxiliary film pressing tool (41) is used and also
show examples in which a film is laminated on hypothetical articles
(310) based on an interior component of an automobile.
[0039] First, with the first chamber and the second chamber of the
film-forming apparatus (110) open to the atmosphere as shown in
FIG. 2A, articles (310) to be laminated are placed on a supporting
table (61) in the second chamber (21) and a sheet-like film (210)
to be laminated on the articles (310) is placed on the film holding
member (31).
[0040] However, the auxiliary film pressing tool (41) is placed on
the bottom of a frame having an opening in the first chamber (11).
For example, the axis of the auxiliary film pressing tool (41) is
disposed so as to bisect the approximate center of the opening.
This disposition corresponds to the approximate center of the gap
between the two articles (310).
[0041] FIGS. 2A to 3B, show an example in which the supporting
table (61) is the entire bottom surface of the second chamber, but
the shape and size thereof is not particularly restricted. The
articles (310) may be placed directly on the supporting table (61),
but may be immobilized on pedestals (not shown) prepared according
to the shape of the articles (310) if necessary. Here, two articles
(310) are placed on the supporting table (61), but the number of
articles is not particularly restricted.
[0042] As mentioned hereafter, the film (210) held by the film
holding member (31) is preferably one able to be stretched to at
least 150 to 200%, and even 300%, by being heated. Next, as shown
in FIG. 2B, the whole of the second chamber (21) is moved upwards
using an external driving mechanism (not shown), the first chamber
(11) and the second chamber (21) are closed via the film (210) so
as to form an upper chamber and a lower chamber, and each chamber
is subjected to vacuum drawing so as to form a vacuum (for example,
1 kPa or lower) in each chamber. In addition, a heating means (51)
provided on the ceiling of the first chamber (21) is turned on so
as to heat the film (210). Moreover, the heating means (51) is not
particularly restricted, but in order to be able to heat
efficiently even in a vacuum, the heating means is preferably one
able to use radiation heat, for example an infrared lamp
heater.
[0043] Next, as shown in FIG. 3A, the supporting table (61) in the
second chamber (21) is gradually pushed upwards while the film
(210) is being heated, and the supporting table (61) is moved so
that the articles (210) move from the opening on the bottom of the
first chamber to a position at which almost the whole of the
articles are beyond the bottom of the first chamber.
[0044] The film (210) is able to be stretched by being heated by
the heating means (51). The film heating temperature is not
particularly restricted, and can be adjusted to not lower than
80.degree. C. and not higher than 200.degree. C., or not lower than
90.degree. C. and not higher than 180.degree. C., according to the
film being used and the degree of stretching required, for example
approximately 120.degree. C. As the articles (210) move by being
pushed upwards, the stretchable film is stretched by coming into
contact with the surface of the articles and is pressed by the
axially shaped auxiliary film pressing tool (41) disposed at a
location exactly in the gap between the two articles.
[0045] In this state, the first chamber alone is pressurized to a
suitable pressure (for example, atmospheric pressure to 2 MPa). Due
to the pressure difference between the first chamber (11) and the
second chamber, the film (210) follows and closely adheres to the
concavoconvex shape of the exposed surface of the articles (310),
thereby laminating the surface of the articles. Meanwhile because
the film in the gap between the two articles is pressed by the
axially shaped auxiliary film pressing tool (41), lifting of the
film in this gap is inhibited.
[0046] Next, as shown in FIG. 3B, the first chamber (11) and the
second chamber (21) are opened once more and returned to
atmospheric pressure, and the articles (310) on which the film
(210) is laminated are able to be removed to the outside. Unwanted
parts, such as the edges, of the film (310) adhered to the surface
of the articles are then trimmed
[0047] The effect of the auxiliary film pressing tool will now be
explained in greater detail by referring to FIGS. 4 and 5. FIG. 4A
is a simulation-visualized perspective view of a state in which a
film is laminated on two articles (310) and which is formed by a
film lamination process using the above-mentioned film-forming
apparatus of the present embodiment in which the auxiliary film
pressing tool (41) of the present embodiment is used, and FIG. 4B
is a simulation-visualized perspective view of a laminated film
state in which a film is laminated under the same conditions except
that the auxiliary film pressing tool (41) is not used.
[0048] Moreover, the conditions used in this simulation are as
follows.
[0049] 1) Article conditions: Two automobile door parts were used.
The maximum height was 70 mm when using almost the same articles as
the conditions in the working example mentioned below, wherein the
articles had a maximum width of approximately 70 mm, a maximum
length of approximately 205 mm and a height of approximately 33 mm,
and were placed on a pedestal. The two door parts were disposed in
the same orientation on the supporting table so that the long axes
that pass through the center of gravity of the articles were
parallel, and the minimum distance between the two door parts was
25 mm.
[0050] 2) Film conditions: The film area was 260 mm.times.260 mm
and the film temperature during the lamination was 120.degree. C.
The coefficient of thermal expansion of the film was
10.sup.-5/.degree. C., the elastic modulus of the film at the film
lamination temperature was 19.4 MPa, the Poisson's ratio was 0.45
and the yield stress was 0.53 MPa.
[0051] 3) Auxiliary film pressing tool conditions: An axially
shaped member having a cross sectional diameter of 2 mm was
disposed in the approximate center of the gap between the two
articles.
[0052] According to the results of the simulation, in cases in
which the auxiliary film pressing tool (41) was not used lifting of
the film readily occurred, especially on the ends of the two
articles (310), and film lifting such as inter-article "fins"
ultimately occurred, as shown at a circle drawn by a broken line in
FIG. 4B.
[0053] However, as shown in FIG. 4A, according to the results of
the simulation, in cases in which the film was laminated on the
articles using the above-mentioned film-forming apparatus of the
present embodiment in which the auxiliary film pressing tool (41)
of the present embodiment was used, it was possible to confirm that
almost no "fins" occurred due to lifting of the film in cases where
the distance between the two articles was also 25 mm.
[0054] Because it is possible to effectively inhibit film lifting
(which readily occurs in interarticle spaces when laminating a
plurality of articles) by using the auxiliary film pressing tool
(41) of the present embodiment in this way, it is possible to
reduce the gap between the articles. Therefore, because it is
possible to place a higher number of articles in a single chamber,
it is possible to greatly improve film lamination productivity.
[0055] For example, in a case in which four articles (310a to 310d)
are evenly distributed on a supporting table, as shown in FIG. 5,
the pitch (D1) in the long axis direction and the pitch (Ds) in the
short axis direction that pass through the center of gravity of
each article are such that the inter-article pitch (D1) must be at
least 106 mm or greater and the inter-article pitch (Ds) must be
253 mm or greater in order to inhibit film lifting if the auxiliary
film pressing tool (41) of the present embodiment is not used.
However, in cases where an axially shaped auxiliary film pressing
tool (41) is disposed in the approximate center of the gap between
the articles in both the long axis direction and the short axis
direction, the inter-article pitch (D1) can be reduced to 91 mm and
the inter-article pitch (Ds) can be reduced to 223 mm while still
inhibiting film lifting. In other words, it is possible to increase
the disposition efficiency by 24% in cases where, for example, four
articles are disposed as shown in FIG. 5. In cases where a large
number of articles are placed in a single chamber, it is possible
to increase the number of articles by using the auxiliary film
pressing tool (41).
[0056] Moreover, in cases where the number of articles in a single
chamber is further increased, by disposing auxiliary film pressing
tools in the approximate center of the gaps between the articles,
it is possible to inhibit film lifting, improve the followability
of the film to the surface of the articles, and therefore unify the
state of lamination on the articles.
[0057] Moreover, in a simulation model in which a cuboid having a
height (H), a width (W) and a length (L) is used as an article and
two articles having the same shape are disposed parallel to each
other in the long axis direction thereof at an inter-article
distance (D), because the occurrence of fins due to film lifting
was significant if the ratio of the inter-article distance (D) to
the height of the article (H) (D/H) is small or if the ratio of the
length of the article (L) to the height of the article (H) (L/H) is
small, using auxiliary film pressing tools increases the fin
inhibition effect.
[0058] Furthermore, the auxiliary film pressing tool may be
provided with a pressure sensitive adhesive layer on the surface
that comes into contact with the film so as to hold the film on the
pressure sensitive adhesive layer. When laminating the surface of
an article, because the film is softened by being heated, the
central part of the film can sag under its own weight. In
particular, increasing the area of the chamber in order to increase
productivity, causes significant sagging in the center of the film
due to gravity, meaning that the difference in lamination
conditions between the center and the edges of the film grows
large. Because differences in lamination conditions from location
to location also bring about differences in the stretchability of
the film, it is difficult to achieve uniform decoration in some
locations in cases where a decorative film is to be laminated. The
pressure sensitive adhesive layer provided on the auxiliary film
pressing tool holds the film and prevents the film from sagging,
thereby enabling a more uniform state of lamination.
[0059] Moreover, the pressure sensitive adhesive film used in such
cases is not particularly restricted, but it is possible to use a
commonly used adhesive such as an acrylic, polyester-based,
urethane-based, rubbery, or silicone-based adhesive. Of these, it
is preferable to use an adhesive having a heat resistance that can
withstand the heating conditions used in the lamination process,
such as 120.degree. C. or higher, 150.degree. C. or higher, or
180.degree. C. or higher. For example, the use of an acrylic
pressure sensitive adhesive is preferred. The pressure sensitive
adhesive layer can be formed using a variety of coating methods,
but it is possible to use a pressure sensitive adhesive layer used
in commercially available double-sided sticky tapes and apply this
layer to the pressing surface of the auxiliary film pressing
tool.
[0060] Furthermore, the auxiliary film pressing tool may be
provided with a thermal sensor. As the auxiliary film pressing tool
can contact a film, temperature of the film can be measured more
correctly, and therefore heating conditions of the film can be
controlled more accurately.
[0061] FIG. 3 and FIG. 4 show examples of auxiliary film pressing
tools having axially shaped film pressing parts, but as long as it
is possible to effectively inhibit film lifting according to the
shape, number, disposition, and so on of the articles being used,
the shape of the auxiliary film pressing tool is not restricted. In
addition, the auxiliary film pressing tool can be effectively used
whether laminating a plurality of articles or just a single
article. Therefore, the auxiliary film pressing tool is preferably
designed according to the specific film lamination conditions.
[0062] FIG. 6 is a flow chart showing an example of the process for
designing the shape and disposition of an auxiliary film pressing
tool. By means of a simulation, the state of film lamination when
not using an auxiliary film pressing tool is first understood, from
which it is possible to identify regions in which film lifting can
readily occur. Based on the results of this simulation, it is
possible to decide upon the shape of the auxiliary film pressing
tool.
[0063] Computational methods used in such simulations can be, for
example, finite element methods, and more specifically an explicit
method, which is a type of finite element method. For example, it
is possible to carry out simulations by using Abaqus, which is
commercially available proprietary simulation software sold by
Simulia that carries out finite element analysis.
[0064] A specific simulation will now be carried out according to
the procedure shown in FIG. 6. Firstly, data relating to the
physical properties of the film, which is essential for the
simulation, is acquired (1010). These physical property values
include data relating to the stretchability of the film under the
film lamination conditions, which is obtained from tensile tests or
viscoelasticity tests.
[0065] Next, data relating to the three-dimensional shape of the
article to be laminated is acquired (1020). This data is usually
acquired as 3D CDA data for the article. Moreover, in cases in
which the article is a small component having a complex shape
(having small holes or protrusions and so on), it is acceptable to
simplify data relating to the shape of the article because this has
little effect on the simulation results but complicates the
computations. In addition, in cases where the article is
constituted by many components, it is acceptable to treat these
components together as a single article.
[0066] Next, a pedestal for immobilizing the article is designed
(1030). The pedestal is designed according to the shape of the
article. The design of the pedestal is based on the shape, size,
and height of the article, the immobilization angle of the article,
the number of articles, the positional relationship of the pedestal
to the article, and is also based on data not relating to the shape
of the article, such as the concavoconvex shape of the pedestal
itself.
[0067] Next, the film lamination process conditions are acquired
(1040). Here, the process conditions include the size of the film
being laminated on the article (the size of the frame of the film
holding member in the vacuum forming apparatus), the film heating
temperature during lamination, and the speed at which the
supporting table in the second chamber is raised. On the basis of
the data acquired above, a simulation is carried out into the state
of the film laminated on the article (1050).
[0068] Based on the results of the simulation, an evaluation is
carried out into the followability of the laminated film to the
shape of the surface of the article (1060). Specifically, an
evaluation is carried out as to whether the stretching of the
laminated film goes beyond the degree of stretching at which film
breakage is possible and also as to whether film breakage is
possible due to localized extreme stretching in places. If it
appears as a result of these evaluations that good film lamination
can be carried out, the design process is ended (1100), but if the
film lamination evaluation results indicate that the shape of the
pedestal needs to be changed, the pedestal shape design is
reevaluated (1040).
[0069] When the pedestal shape design process is complete, another
film lamination simulation is carried out on the basis of this data
(1050) and the film lamination followability is evaluated once more
(1060). Next, the auxiliary film pressing tool is designed on the
basis of these results in order to inhibit lifting of the film that
cannot be addressed merely by changing the design of the pedestal
(1070). In other words, the shape, size, disposition, and so on of
the auxiliary film pressing tool are designed.
[0070] Data for the designed auxiliary film pressing tool is added
and a simulation of the film lamination results is carried out once
more (1080). From the results of this simulation, an evaluation
into the followability of the laminated film is carried out (1090),
and in cases where satisfactory film followability is not achieved,
the auxiliary film pressing tool is designed again. The evaluation
(1090) and the design of the auxiliary film pressing tool (1070)
are repeated if necessary in order to establish the shape of the
auxiliary film pressing tool. Furthermore, if it is possible to
confirm from the simulation of the film lamination results (1080)
and the evaluation (1090) that good film followability is possible,
the design process is ended.
[0071] FIG. 7 and FIG. 8 show examples of different articles and
examples of the results of film lamination simulations carried out
using auxiliary film pressing tools for these articles. FIG. 7A
shows the results of a film lamination simulation in a hypothetical
case in which a film is laminated on a single article (320) having
a shape in which a part of a ring is missing. It is understood that
film lifting occurs in parts of articles having a shape in which a
part of a ring is missing. An auxiliary film pressing tool for this
article can be a three-dimensionally shaped auxiliary film pressing
tool (42) having a film pressing part (42a) for only the missing
part of the ring. FIG. 7B shows the results of a film lamination
simulation in which the auxiliary film pressing tool (42) is used.
It was understood that it is possible to effectively inhibit
lifting of the film.
[0072] In this way, it is possible to use an auxiliary film
pressing tool having a film pressing part (42a) for only this part
in cases where partial film lifting occurs due to the shape of even
a single article. In addition, the shape of the auxiliary film
pressing tool (42) can be a variety of shapes according to the
shape of the article.
[0073] FIG. 8A shows the results of a film lamination simulation
for a case in which two L-shaped articles are disposed in a
rotationally symmetrical manner, and FIG. 8B shows the results of a
film lamination simulation for a case in which an auxiliary film
pressing tool (43) having a clamp shape is used in accordance with
the shape of the gap between the two articles. It was understood
that it is possible to effectively inhibit lifting of the film
between the articles.
[0074] In the examples given above, an auxiliary film pressing tool
is obtained by processing an axially shaped member according to the
shape of the article or the shape of the gap between articles, that
is, according to the disposition of the article(s), but the
auxiliary film pressing tool is not limited to axially shaped
members, and can be a band shaped member or a member having a width
size or shape that can be changed according to the gap between the
articles. In addition, the auxiliary film pressing tool may be
obtained by three-dimensionally processing an axially shaped or
band shaped member.
[0075] The material of the auxiliary film pressing tool may be any
rigid material such as a metal, alloy, ceramic or heat-resistant
plastic that does not deform at temperatures of not lower than
80.degree. C. and not higher than 200.degree. C., or not lower than
90.degree. C. and not higher than 180.degree. C., which are the
heating conditions during the film lamination.
[0076] The article and film used in the embodiment of the present
invention will now be explained in greater detail.
[0077] It is possible to use a variety of objects as the article to
be laminated with a film. Typical examples include exterior and
interior components for automobiles and decorative components for
motorcycles. Specific examples of interior components for
automobiles include door grips, switch panels for electric windows,
garnishes, steering wheels, gear shift panels, console boxes, drink
holders, center consoles, instrument panels, center garnishes, door
garnishes, dash boards, scuff plates, and pillars. In addition,
examples of exterior components for automobiles include door
handles, front grilles, pillars, back doors, pillar garnishes, lamp
bezels, moldings, fuel caps, emblems, bumpers, and door mirror
covers. Furthermore, examples of decorative components for
motorcycles include fenders, shrouds, fuel tanks, fuel tank covers,
side covers, middle cowlings, side cowlings, upper cowlings, frame
covers, radiator covers, front covers, muffler covers, and side
panels.
[0078] Furthermore, other articles include domestic appliances,
electronic components, and furniture. Further specific examples
include veneers for refrigerators, television bodies, veneers for
laptop computers, decorative parts for cellular telephones, bodies
for personal computers, chairs, desks, shelves, lavatory seat lids,
decorative and reflective films applied to helmets, planters,
flower pots, reflective films for lighting, lamp shades, suitcases,
and musical instruments.
[0079] The film used for the lamination is not particularly
restricted, and can be a heat-resistant film able to withstand the
heating temperature used during the lamination. For example, it is
possible to use a single or composite thermoplastic resin such as a
polyester such as polyethylene terephthalate (PET), polybutylene
terephthalate (PBT) or polyethylene naphthalate (PEN), polyvinyl
chloride (PVC), a polycarbonate (PC), an
acrylonitrile/butadiene/styrene copolymer (ABS), an
acrylonitrile/ethylene-propylene-diene/styrene copolymer (AES), a
polyurethane, a poly(meth)acrylate such as poly(methyl
methacrylate), or a polyolefin such as polyethylene or
polypropylene. Of these, poly(vinyl chloride), polyurethanes,
poly(meth)acrylates, polypropylene, polycarbonates, ABS and AES
exhibit stretchability during heating and adhesion to an adherend
while exhibiting excellent weather resistance properties.
Poly(vinyl chloride), polyurethanes, poly(meth)acrylates, and
polypropylene are especially suitable.
[0080] In general, the film may be a laminate film having a
multilayer structure that contains a monolayer or multilayer base
film formed by cast molding, extrusion molding, and so on and which
optionally contains a printed layer, a metalized film, a pressure
sensitive adhesive layer, and so on the base film.
[0081] In order to improve the protection, weather resistance
properties, strength, and aesthetic appearance of a surface, the
base film of the film may be a laminated film formed from the same
or different materials.
[0082] In addition, for reasons of decoration, the laminated film
body may contain a monolayer or multilayer printed layer. The
printing may be carried out by using a known method such as screen
printing, gravure printing, offset printing, ink jet printing, or
electrostatic coating. The printed layer is disposed, for example,
between the base film and the pressure sensitive adhesive
layer.
[0083] In order to impart decorative properties, one or more layers
of the film may be subjected to processing such as deposition of
one or more metal films of chromium, aluminum, titanium, indium,
tin, nickel, stainless steel, silver, gold, copper, or titanium
and/or application of a coating that contains powdered metal
microparticles. A deposited film of indium or a coating layer of
powdered metal microparticles is especially preferred since it does
not cause whitening or cracking of the metal film when the film is
laminated. The thickness of deposited metal layer or layer
containing powdered metal microparticles is not particularly
limited, and can be a thickness set according to the intended
design and/or the light transmittance, such as between several
nanometers and several dozen nanometers.
[0084] The film may also contain additives such as plasticizers,
antioxidants, UV absorbents, pigments, and fillers.
[0085] The thickness of the overall film is not restricted, but it
is possible to improve the followability of the film to the shape
of the surface of the article if this thickness in approximately
200 .mu.m or less, and especially approximately 100 .mu.m or less.
However, from the perspective of protecting the article, the
minimum thickness of the film is 50 .mu.m or more, and preferably
80 .mu.m or more, in order to ensure a certain degree of film
strength.
[0086] The film may contain a pressure sensitive adhesive layer on
the surface that comes into contact with the surface of the
article. The pressure sensitive adhesive layer may be formed by
coating, spraying, and so on. The thickness of the pressure
sensitive adhesive layer is not restricted as long as peeling or
folding does not occur when the film is laminated and bleeding does
not occur at high temperatures. For example, the thickness of the
pressure sensitive adhesive layer can be approximately 10 to
approximately 50 .mu.m or, in a different mode, approximately 20 to
approximately 40 .mu.m.
[0087] In cases where the surface of the article is an olefinic
resin such as polyethylene or polypropylene, which have a low
surface free energy and therefore do not adhere readily, it is
possible to incorporate a tackiness-imparting agent such as a
tackifier in the pressure sensitive adhesive layer in order to
facilitate adhesion.
[0088] Moreover, in order to increase the surface free energy of
the article being laminated, thereby increasing wettability and
improving adhesive strength, it is possible to subject the surface
of the article to plasma treatment, corona discharge treatment, and
so on. In cases where the surface of the article is an olefinic
resin such as polyethylene or polypropylene in particular, such
treatments are effective for improving the adhesive strength.
EXAMPLES
[0089] A working example of the present invention will now be
explained.
Example
[0090] A double-sided vacuum forming machine (NGF-0709,
manufactured by Fu-se Vacuum Forming) was used as the film-forming
apparatus. Two door parts, which were the articles, were placed on
pedestals on the supporting table in the second chamber in a
rotationally symmetrical manner so that the long axes passing
through the centers of gravity of the articles were parallel. The
shape of the door parts was almost the same as that used in the
simulation shown in FIG. 4A, and the size of each part was such
that the maximum width was approximately 70 mm, the maximum length
was approximately 205 mm and the height was approximately 33 mm,
meaning that the maximum height when placed on the pedestal was 70
mm. The minimum distance between the two door parts was 25 mm.
[0091] An iron wire used in wire hangers and having a
cross-sectional diameter of 2 mm was prepared as the auxiliary film
pressing tool. This was disposed on a frame, which measured 260
mm.times.260 mm, had an opening and was attached to the bottom of
the first chamber of the vacuum forming apparatus, so that the wire
passed through the approximate center of the opening, both ends of
the wire were bent, and the wire was immobilized by being tied to
the frame. In this way, the wire was disposed in a position
corresponding to the approximate center of the gap between the two
door parts.
[0092] Meanwhile, the film was immobilized by the frame-like film
holding member. The area of the opening in the film holding member
was almost the same as that of the area of the opening of the
bottom of the first chamber. The film used was a decorative film
having a 7-layer structure as indicated below (ITF1201J produced by
Sumitomo 3M Ltd.). The type and thickness of each layer are as
indicated below. Moreover, a liner on the reverse side of the film
was peeled off at the time of lamination, thereby exposing an
acrylic pressure sensitive adhesive layer (the first layer) that
comes into direct contact with the surface of the article.
Structure of the Film Used
[0093] First layer: Acrylic pressure sensitive adhesive layer,
thickness 40 .mu.m [0094] Second layer: Primer layer, thickness 1
.mu.m [0095] Third layer: Urethane layer, thickness 30 .mu.m [0096]
Fourth layer: Metal deposition layer, thickness 1 .mu.m [0097]
Fifth layer: Urethane pressure sensitive adhesive layer, thickness
15 .mu.m [0098] Sixth layer: Colored transparent acrylic layer,
thickness 30 .mu.m [0099] Seventh layer: Transparent acrylic layer,
thickness 30 .mu.m
[0100] Using the procedure explained above with reference to FIG.
3, the film was laminated on the articles. In other words, the
first chamber and the second chamber were sealed, separate vacuums
were drawn in each chamber so that the pressure in each chamber was
1 kPa or lower, and the film was heated to a temperature of
approximately 120.degree. C. by an infrared lamp attached to the
ceiling of the first chamber. Next, as the supporting table in the
second chamber was pushed up, a part of the film was pressed by the
wire, which was the auxiliary film pressing tool. The first chamber
was then pressurized to a pressure of approximately 2 kPa. In this
way, the film was laminated on the surface of the article. Despite
the distance between the articles being only approximately 25 mm,
it was possible to laminate the film without the occurrence of film
lifting (fins).
Comparative Example
[0101] By way of a comparative example, film lamination was carried
out using a vacuum forming apparatus but without using an auxiliary
film supporting tool. The film lamination was carried out using the
same conditions as those used in the working example, except that
the auxiliary film supporting tool was not used. However, the
distance between the articles was set to 40 mm, 45 mm, 50 mm, and
55 mm. When the distance between the articles was 40 mm,
significant fin-like film lifting was observed between the
articles, and although the height of the film lifting was reduced
by approximately half when the distance between the articles was 45
mm, some fins remained. When the distance between the articles was
50 mm, some film lifting remained and it was not possible to
achieve complete film followability. In order for almost no film
lifting to occur between the articles, it was necessary to increase
the distance between the articles to 55 mm.
* * * * *