JP2003276074A - Method and apparatus for producing preformed film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a preformed film which can precisely align a film and a preforming die to reduce loss of the film and an apparatus for the method. <P>SOLUTION: The film 5 clamped by an air compressor 1 and a film clamping means 2 is heated to its softening temperature or above by a heater 10 arranged between the film clamping means 2 and a preforming mother die 3, and air in a space formed between a recessed part 90 of the compressor 1 and the film 5 is discharged so that the film 5 is kept flat. The compressor 1 is made to approach the mother die 3, and the air in the space formed between the recessed part 90 of the compressor 1 and the film 5 is compressed. In this way, the film shaped along the unevenness of the mother die 3 is obtained from the flat film 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing of a mobile phone, an instrument panel of an automobile, a heater control panel, a center panel, buttons and knobs used for those panels,
The present invention relates to a preform film manufacturing method and a preform film manufacturing apparatus, which are applied to a method of integrating a film on the surface of a molded product having a raised three-dimensional shape such as a shift lever housing. The term “preform” means that a film is molded into a three-dimensional shape that substantially matches the shape of the cavity forming surface of the injection molding die.

[0002]

2. Description of the Related Art Conventionally, there have been the following methods for producing a preform film. (1) The film is sandwiched between the opening edges of the recesses of the air pressure means, the film is preheated to its softening temperature, and the air pressure molding is used to bring the film into close contact with the preforming mold to deform the film into a predetermined three-dimensional shape. There is a method of forming a film by cooling the film and maintaining its three-dimensional shape. (2) The film is sandwiched between the opening edges of the recesses of the air pressure means, and the film is not preheated to its softening temperature, but is brought into close contact with the preforming mold by high pressure air pressure molding to form the film into a predetermined three-dimensional shape. There is a method in which the film is molded by deforming it, cooling the film, and maintaining its three-dimensional shape.

[0003]

However, in the method (1), since the film is heated after the film is sandwiched between the opening edges of the recesses of the compressed air means having the recessed portions, the film is heated by the recessed portions of the compressed air means and the film. The expansion of the air in the sealed space tends to cause the film to swell, or the film itself to swell or wrinkle or sag due to expansion and contraction. As a result, the film and the preform die cannot be accurately aligned. In the method (2), since the film is not heated, the film is deformed into a three-dimensional shape while the stress remains inside the film. As a result, the film is likely to be cracked due to external thermal and physical impacts after deformation, or due to changes over time, resulting in large film loss. In addition, the surface of the film is easily scratched at the corners of the preform die during compressed air. In particular, in a portion where the film is sharply bent, the film has an unnecessary broken line, and the film loss is large. Further, a high-voltage generator is required, the danger of handling the high-voltage generator increases, and the cost of the device is high in terms of safety measures. The present invention overcomes these drawbacks of the prior art, and can perform the alignment of the film and the preform die with high accuracy,
An object of the present invention is to provide a preform film manufacturing method and a preform film manufacturing apparatus in which film loss is small.

[0004]

A method of manufacturing a preform film according to the present invention is directed to a film sandwiched by a pneumatic clamping means having a concave portion facing the film and having a pneumatic hole and a discharge hole, and a film clamping means,
The heating means introduced between the film clamping means and the preform master mold heats the film to its softening temperature or higher, while discharging the air in the space formed between the concave portion of the compressed air means and the film. The film is kept flat by the heating means, the heating means is retracted, the compressed air means is brought close to the preform master mold, and the space formed between the concave portion of the compressed air means and the film is compressed. It is characterized in that a film having a shape along the irregularities of the preform mother die is obtained from the film kept flat. Further, in the method for producing a preform film of the present invention, the film is kept flat by keeping the space formed between the concave portion of the compressed air means and the film to be the same as the external atmospheric pressure. You can also Further, in the method of manufacturing a preform film of the present invention, the space formed between the concave portion of the compressed air means and the film is set as a closed space, and the film is obtained by forcibly discharging air from the discharge hole of the compressed air means. It can also be kept flat.
The preform film manufacturing apparatus of the present invention is a preform mother die having irregularities placed on the exhaust means,
A film clamping means having a frame-shaped clamp capable of approaching and separating from the preform mother die, a concave portion facing the film, a compressed air hole and a discharge hole, and a preform mother body via the film clamping means. It is characterized in that it is provided with a compressed air means capable of approaching / separating from the mold and a heating means capable of introducing / withdrawing between the film clamp means and the preform mother die. In the preform film manufacturing apparatus of the present invention, the exhaust means, the film clamp means, and the compressed air means may be arranged in the vertical direction. Further, in the apparatus for producing a preform film of the present invention, the heating means may be an assembly of heaters whose temperature can be individually controlled. Further, in the preform film manufacturing apparatus of the present invention, the film holding portion for removing the preformed film and the film holding portion for mounting the unpreformed film on the frame-shaped clamp are back to back. It may have a robot hand arranged at.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. For convenience of description, first, the preform film manufacturing apparatus of the present invention will be described.
The preform film manufacturing apparatus of the present invention is a preform mother die having irregularities placed on the exhaust means,
A film clamping means having a frame-shaped clamp capable of approaching and separating from the preform mother die, a concave portion facing the film, a compressed air hole and a discharge hole, and a preform mother body via the film clamping means. It is characterized in that it is provided with a compressed air means capable of approaching / separating from the mold and a heating means capable of introducing / withdrawing between the film clamp means and the preform mother die.

For convenience of explanation, the pneumatic means 1 will be described first.
The air pressure means 1 presses air against the film 5 to bring the film 5 into close contact with the unevenness 7 of the preform mother die 3 without a gap, thereby obtaining the film 5 having a shape along the unevenness 7 of the preform mother die 3. It is for. Pneumatic means 1
Has a concave portion 90 facing the film 5 and a compressed air hole 6 and a discharge hole 60, and can approach and separate from the preform mother die 3 via the film clamping means 2. The compressed air unit 1 has a function of sandwiching the film 5 in the opening edge 31 of the recess 90 in cooperation with the film clamp unit 2. The compressed air means 1 has a function of introducing compressed air from the compressed air hole 6 into the recess 90 of the compressed air means 1 after contacting the exhaust means 4 with the film clamp means 2 interposed therebetween. As the pneumatic means 1, there is a device generally used for air blow molding.

The compressed air means 1 has a compressed air hole 6 on the wall surface forming the recess 90. The compressed air hole 6 is connected to an air compression device 8 such as a high pressure compressor. By opening the valve of the compressed air hole 6 of the compressed air means 1 and sending compressed air from the air compression device 8, the recess 90 of the compressed air means 1 is opened.
The inside of the space 9 formed by the film and the film has a high pressure.
The pressure for producing compressed air is preferably 1 Mpa to 5 Mpa. In this invention, since the film 5 can be pushed and stretched while the film 5 is still heated to a high temperature, the film 5 can be adhered to the preform mother die 3 without a gap even with a relatively low pressure. The set value of the pressure for producing compressed air is a laminated film of an ABS resin film and an acrylic resin film and has a total thickness of 50.
When using those having a thickness of 0 μm, a setting value of 2 MPa is preferable at a heating temperature of 250 ° C. Also, the thickness is 200μ
In the case of a polycarbonate resin film of m, a setting value of 4.5 MPa is preferable at a heating temperature of 250 ° C.

The compressed air means 1 has a discharge hole 60 on the wall surface forming the recess 90. The discharge hole 60 keeps the film 5 flat by discharging the air in the space 9 when the film sandwiched between the opening edges 31 of the recesses 90 of the compressed air means 1 is heated above its softening temperature. It is a hole for making a state. When the pressure in the space 9 is equal to or higher than the atmospheric pressure, the pressure in the space 9 can be reduced to the atmospheric pressure by opening the valve of the discharge hole 60. When the compressed air is sent into the space 9, the valve of the discharge hole 60 is closed. When the atmospheric pressure in the space 9 is much higher than the atmospheric pressure, not only is the valve of the discharge hole 60 opened, but also
The air can be forced out.

Examples of the material of the main body forming the compressed air means 1 include iron, aluminum, copper, nickel and alloys based on them, or epoxy resin containing metal powder. The reason why these materials are selected is that the main body forming the compressed air means 1 needs to have strength to withstand the pressure caused by the introduction of compressed air.

The film clamp means 2 is a frame-shaped clamp. The frame-shaped clamp cooperates with the compressed air means 1 to sandwich the film 5 and move it toward the preform mother die 3 (see FIG. 7).

The frame-shaped clamp is composed of an upper clamp that is pressed from the upper surface of the film 5 and a lower clamp that is pressed from the lower surface of the film 5. The two clamps may sandwich the film 5 (not shown). No). In this case, since the predetermined annular portion of the film 5 is sandwiched, even when the film 5 is displaced, contracted, or stretched due to the heating of the heating means 10, it can be minimized.

The frame-shaped clamp may be a dividable one (not shown). For example, there is a quadrangular frame-shaped clamp without division before the division, and there are two clamp pieces having a U-shape after the division. The frame-shaped clamp may be attached with a clamp heater device or a temperature control circuit (not shown) using a heating fluid medium. The reason is that the temperature distribution of the film 5 is not uniform due to the heat of the film 5 being taken by the frame-shaped clamp, and the film 5 is stretched when the film 5 is closely adhered to the irregularities of the preform mother die 3 without a gap. This is to prevent the portion having a low degree of stretching from being broken and the portion having a high degree of stretching to be wrinkled. Further, it is possible to preliminarily strongly heat only the portion of the film 5 where the temperature tends to decrease. As the clamp heater device, there is a rod-shaped sheathed heater 34 and the like, which may be embedded in four pieces of a frame-shaped clamp (FIGS. 7A and 7B). The temperature control circuit has a structure in which heated water is drawn into the frame clamp and circulated inside the frame clamp from an external device that can control the temperature by heating a fluid medium such as water or oil. There is one.

The frame-shaped clamp may have a bush 13 that matches the tapered pin 12 formed on the upper surface of the exhaust means 4 (see FIGS. 7A and 7B, FIGS. 9 to 13). When the frame-shaped clamp, the preform mother die 3 and the exhaust means 4 come into contact with each other, the unevenness 7 of the preform mother die 3
This is to prevent the film 5 and the film 5 from being misaligned. The bush 13 is preferably formed at least in the center of two opposite sides of the frame-shaped clamp.

The frame-shaped clamp may have two or more film positioning pins 32 on its upper surface (FIG. 7).
(B), see FIGS. 9 to 13). This is to prevent the frame-shaped clamp and the film 5 from being displaced. The taper pin 12, the bush 13, and the film positioning pin 32 can prevent the unevenness of the preform mother die 3 and the film 5 from being misaligned. The number of the film positioning pins 32 is 2 or more, preferably 4 to
Eight is good. This is to minimize misalignment in the left / right, up / down, and rotation directions. The film positioning pin 32 is preferably formed at the central portion or the corner portion of each side of the frame-shaped clamp. The length of the film positioning pin 32 is
5-10 mm is preferable. The film positioning pin 32 preferably has a diameter of 2 to 8 mm.

The preforming mother die 3 is used to preform the film 5 into a three-dimensional shape corresponding to the shape of the cavity forming surface of the injection molding die described later by closely adhering the film 5 to the surface thereof. (See FIG. 8). The preform mother die 3 has an exhaust hole 14
A small hole may be formed in the vicinity of the protrusion or a slit 33 may be formed in order to connect with the protrusion (see FIG. 8), or the protrusion itself may have a minute vent hole through which air passes. . Porous metals, porous ceramics, and the like may be used as the convex portion itself having minute air holes through which air passes. Examples of the material of the preform mother die 3 include iron, aluminum, copper, nickel and alloys based on them, or epoxy resin containing metal powder. The surface of the preform mother die 3 may be coated with a fluorine resin, a silicone resin, or the like.

The preform mother die 3 may have a plurality of convex portions (see FIG. 8). For example, there is one in which a plurality of convex portions has a three-dimensional shape of an upper lid of a mobile phone and is formed side by side in two rows and two columns (see FIG. 8A). Also,
In order to prevent air from leaking and ensure exhaust from the exhaust hole 14, there is a preform mother die 3 having a rising edge (see FIG. 8B, FIG. 14 and FIG. 15). Each convex may have the same three-dimensional shape as the upper lid of the mobile phone. The plurality of protrusions may have different three-dimensional shapes.

The exhaust means 4 covers the unevenness 7 of the preform mother die 3 with the film 5 after the unevenness 7 of the preform mother die 3 is covered by the compressed air means 1 coming into contact with the exhaust means 4. The air in the gap is exhausted from the exhaust hole 14 to obtain the film 5 having a shape along the irregularities 7 of the preform mother die 3. The exhaust means 4 may have a taper pin 12 that matches the bush 13 formed in the frame-shaped clamp (see FIG. 7B and FIGS. 9 to 13). This is for preventing the unevenness 7 of the preform mother die 3 and the film 5 from being displaced when the frame-shaped clamp, the preform mother die 3 and the exhaust means 4 contact each other.

The relationships among the constituent elements other than the heating means 10 in this embodiment are as follows (FIGS. 1 to 5 and 9).
(See FIG. 13). The preform mother die 3 is fixed onto the exhaust means 4 with bolts or the like. A frame-shaped clamp is installed above the preform mother die 3. The frame clamp is
It is supported by the frame-shaped clamp support portion 15, and can be moved between the compressed air means 1 and the exhaust means 4 in the mold open state by a hydraulic cylinder or an air cylinder. Further, the compressed air means 1 is mounted on the compressed air means supporting portion 16 and stands by with the exhaust means 4 at a constant interval. If a robot hand, which will be described later, comes in, this interval may be an interval in which this robot hand can enter. The compressed air means 1 comprises a compressed air means supporting portion 16
An opening / closing operation is performed between the exhaust means 4 and the hydraulic cylinder 19 attached to the.

The heating means 10 is inserted between the frame-shaped clamp and the preform mother die 3 to heat from the lower surface of the film 5 sandwiched between the compressed air means 1 and the film clamping means 2, and then the frame-shaped clamp. It is possible to retreat from between the preform mother die 3 (see FIGS. 1 to 6). As an example of the heating means 10, there is a heating part 17 and a driving part 22. Heating part 17
Have an area that covers the lower surface of the frame-shaped clamp.
The heating unit 17 may be the heater panel 11 (see FIG. 6), a ceramic heater in which a heater is cast in a ceramic plate, or a pipe heater. The heating unit 17 can simultaneously heat the film 5 and the preform mother die 3. The heating unit 17 may be composed of a plurality of divided heating units 23 (the heater panel is divided into four parts) whose temperature can be controlled individually (see FIG. 6). When the preform mother die 3 described above has a plurality of convex portions, one divided heating portion 23 is provided for each convex portion.
Can be adapted. Further, the temperature setting of the divided heating unit 23 corresponding to the convex portion of the three-dimensional shape having a large rise can be increased, and the temperature setting of the divided heating unit 23 corresponding to the convex portion of the three-dimensional shape having a small rise can be lowered. Further, while the temperature setting of the division heating unit 23 corresponding to the portion of the film on which the pattern layer having a large film thickness is formed is increased, the division heating corresponding to the part of the film such as a window portion where the pattern is not formed is divided. The temperature setting of the part 23 can be lowered. The drive unit 22 introduces the heating unit 17 between the compressed air means 1 and the preform mother die 3 and retracts it from between the compressed air means 1 and the preform mother die 3. The drive unit 22 is installed on the heating means mounting table 24. The drive unit 22 may be a rodless cylinder or the like that uses the driving force of an actuator by air. Alternatively, the driving force of an electric actuator such as a combination of a motor and a timing belt or a combination of a motor and a ball screw may be used.
The heating means mounting table 24 is provided with rails 25 on which the drive unit 22 moves.

The injection molding die having the cavity forming surface that matches the three-dimensional shape of the convex portion of the preform mother die 3 is a desired three-dimensional molded product by closing the male die and the female die. To form a cavity for molding (not shown). The film 5 formed into a three-dimensional shape by the film forming apparatus of the present invention is used by fitting or covering the cavity forming surface. As a three-dimensional shape of the cavity forming surface, there is a three-dimensional shape of the upper lid of the mobile phone.

Further, the film forming apparatus of the present invention has a film holding portion for removing the preformed film 5 from the gap between the air pressure means 1 and the frame-shaped clamp, and the non-preformed film 5 in the frame-shaped clamp. You may have the robot hand 29 arrange | positioned back to back with the film holding part for mounting on top (refer FIG.1, FIG.5, FIG.14).

The method for producing the preform film of the present invention will be described below. A method of manufacturing a preform film according to the present invention includes a film clamping means and a preform mother die, the film being sandwiched by a pneumatic clamping means having a concave portion facing the film and having a pneumatic hole and a discharge hole, and a film clamping means. While heating the film above its softening temperature by the heating means introduced during the period, while keeping the film flat by discharging the air in the space formed between the recess of the compressed air means and the film , After retracting the heating means, the compressed air means is brought close to the preform mother die, and the space formed between the concave portion of the compressed air means and the film is compressed so that the film is kept flat. It is characterized in that a film having a shape along the irregularities of the preform mother die is obtained.

First, the air pressure means and the film clamp means 2
The film is sandwiched by and. In other words, after the film is placed on the frame-shaped clamp (see FIGS. 1 and 14), the frame-shaped clamp is pushed up by the hydraulic cylinder,
The frame-shaped clamp comes into contact with the opening edge portion 31 of the compressed air means, and the film 5 is sandwiched between the compressed air means 1 and the frame-shaped clamp (see FIGS. 1, 2, 9, and 15). In order to place the film on the film clamp means 2, a robot may be used to feed the films one by one (see FIG. 1), or a long film wound into a roll shape. May be continuously fed by utilizing the rotational force of the roll. The compressed air means 1 moves along the posts 20 provided on all sides through the compressed air means supporting portion 16.

Next, heating means is introduced between the film clamp means 2 and the preform mother die 3 (FIGS. 2 and 1).
5). That is, the heating part 17 of the heating means is introduced into a position that covers the film 5 sandwiched between the compressed air means 1 and the frame-shaped clamp. The distance between the heating unit 17 and the film 5 can be expanded or contracted by pressing down the compressed air means 1 with a hydraulic cylinder. The heating part 17 of the heating means may be inserted into the frame of the frame-shaped clamp to the extent that it does not contact the film 5. The discharge hole 60 of the compressed air means 1 may be opened before the heating means 10 is introduced between the film clamp means 2 and the preform mother die 3. Alternatively, before the heating means 10 is introduced between the film clamp means 2 and the preform mother die 3, the discharge hole 60 of the compressed air means 1 is sealed and may be opened during heating. Good. When the discharge hole 60 is in the sealed state, the film 5 is effective because it is difficult for the film 5 to hang down by its own weight.

Next, while heating the film 5 by the heating means 10 above its softening temperature, the air in the space 9 formed by the concave portion of the compressed air means and the film 5 is discharged to flatten the film 5. It is maintained (see FIG. 3). What is the softening temperature of the film 5? JIS K72
06, the numerical value measured by ISO306. When the film 5 is heated, the air in the space 9 formed by the recess 90 of the compressed air means 1 and the film 5 is also heated, and the volume in the space tends to expand. Therefore, the film 5 sandwiched between the compressed air means 1 and the film clamp means 2 tends to bulge into a convex shape. In the present invention, the space 9 is provided in order to prevent the film 5 from bulging into a convex shape even if the film 5 is heated to a softening temperature or higher, or to return to a flat state even if the film 5 bulges into a convex shape once. Exhaust the air inside. Specifically, by keeping the inside of the space 9 at the same atmospheric pressure as the outside air at all times, the air to be expanded in the space 9 is discharged from the discharge hole 60 of the compressed air means 1 to keep the film 5 flat. You may do it.
Alternatively, the space 9 may be a closed space, and the expanding air in the space 9 may be forcibly discharged from the discharge hole 60 of the compressed air means 1 to keep the film 5 flat. . When the valve of the discharge hole 60 of the air pressure means 1 is opened, the atmospheric pressure in the space 9 can be lowered to the atmospheric pressure. After the heating means retreats, wind pressure is applied to the film 5 sandwiched between the compressed air means 1 and the frame-shaped clamp while the film 5 is being approached to the preform mother die 3. It is possible to reduce the strength of forced discharge and to balance the pressure in the closed space 9 with the wind pressure. Since the wind pressure is applied to the film 5 while the film 5 sandwiched between the compressed air means 1 and the frame-shaped clamp is being approached to the preforming mother die 3, the film 5 is unlikely to have a convex shape. Because.

Next, after the heating means 10 is retracted, the compressed air means 1 is brought close to the preform mother die 3 and the space 9 is compressed so that the flat film 5 can be used for the preform. A film having a shape along the irregularities of the mother die 3 is obtained. That is, after retracting the heating means from between the pneumatic means and the preform mother die 3 (see FIG. 3), the hydraulic cylinder 19 further pushes down the pneumatic means 1 to move the frame-shaped clamp downward from the fixed position. The compressed air means 1, the film 5 and the frame-shaped clamp are moved to approach the exhaust means 4 while being in contact with each other. When the pneumatic cylinder 1 is further pushed down by the hydraulic cylinder 19, the pneumatic means 1 /
The film 5 / frame-shaped clamp / preform mother die 3 / exhaust means 4 are arranged and contacted in this order (see FIGS. 4 and 12). The film 5 may cover the convex portion of the preform mother die 3 to form a so-called tent, or as shown in FIG. 8B, the convex portion of the preform mother die 3 and the film 5 may be formed. There may be a state in which there is a space between them.

The compressed air means 1 and the exhaust means 4 may be brought into contact with each other while the film 5 is maintained at the softening temperature or higher. For this purpose, it is advisable to heat the film 5 to a temperature 5 to 10 ° C. higher than the softening temperature before retracting the heating means.
By doing this, even when the rising portion of the convex portion of the preform mother die 3 is large, the film 5 is brought into close contact with the convex portion of the preform mother die 3 with a low pressure so as to follow the irregularities 7 of the preform mother die 3. A shaped film 5 can be obtained. Further, the film 5 can be adhered to the preform mother die 3 without any gap in a state where no stress remains inside the film 5. Moreover, no cracks or cloudiness occur on the surface of the film 5. Further, the quality of the film 5 after molding becomes stable.

Next, compressed air is introduced from the compressed air holes 6 of the compressed air means 1 into the space 9 to press the film 5 against the convex portion of the preform mother die 3 and the exhaust holes 1 of the exhaust means 4.
The air in the gap between the film 5 and the preform mother die 3 is pushed out from 4 to bring the film 5 into close contact with the preform mother die 3 (see FIGS. 4 and 12). Exhaust means 4
The air may be forcibly exhausted from the exhaust hole 14 of FIG.

Next, the film 5 is the mother die 3 for preform.
The air in the space 9 is exhausted after the compressed air state is maintained until it is pressed against the unevenness 7 and the deformation is completed.

Next, the hydraulic cylinder 19 raises the pneumatic means 1 to the fixed position of the frame-shaped clamp. When the air pressure means 1 is further raised, the frame-shaped clamp is stopped at a fixed position, and only the air pressure means 1 can be further raised (see FIGS. 5 and 13). The compressed air means 1 / frame-shaped clamp / preform mother die 3 / exhaust means 4 returns to the state having the gap again. As another method, the compressed air means 1 and the frame-shaped clamp may be separated so that only the compressed air means 1 is lifted and the frame-shaped clamp remains in contact with the exhaust means 4 (see FIG. 14). ). In this case, the step of taking out the preformed film 5 and the step of placing the non-preformed film 5 on the frame clamp are performed while the frame clamp remains in contact with the exhaust means 4. (See FIG. 14).

The following method can be used to remove the preformed film 5 from between the air pressure means 1 and the frame-shaped clamp. As shown in FIG. 5, the frame-shaped clamp is attached to the exhaust means 4.
There is a method in which the preformed film 5 is removed with a robot hand or the like after being separated from the film. Alternatively,
As shown in FIG. 14, there is a method of removing the preformed film 5 with a robot hand or the like while the frame-shaped clamp remains in contact with the exhaust means 4. When the surface of the preform mold 3 is coated with a fluororesin or a silicone resin, the film adhered to the surface of the preform mold 3 is peeled off from the surface of the preform mold 3. Easy and effective.

As the film 5 used in the practice of the present invention, there is one in which a pattern layer having a pattern formed thereon, an adhesive layer and the like are sequentially formed on a base material (not shown). The base material is a single film of an acrylic resin, a polypropylene resin, a polystyrene resin, an ABS resin, a polycarbonate resin, a polyester resin, or the like, or a laminated film obtained by laminating a film composed of two or more of these, or a polymer of a polycarbonate resin and a polybutylene terephthalate resin. There are alloys, polymer alloys of polycarbonate resin and ABS resin, and the like.

The softening temperatures of the various base materials are as follows. Acrylic resin alone is approximately 110 ° C., polypropylene resin alone is approximately 80 ° C., polystyrene resin alone is approximately 70 ° C., ABS resin alone is approximately 80 ° C., and polycarbonate resin alone is approximately 140 ° C. The softening temperature of a laminated film obtained by laminating two or more kinds of these films, for example, a laminated film obtained by laminating an acrylic resin and an ABS resin, is about 90 ° C. The softening temperature of the polymer alloy of the polycarbonate resin and the polybutylene terephthalate resin is about 120 ° C. The softening temperature of the polymer alloy of the polycarbonate resin and the ABS resin is about 100 ° C. The softening temperature of the film on which the pattern layer and the like are formed may be considered to be the same as the softening temperature of the base material. The reason is that the thickness of the ink film such as the pattern layer is extremely smaller than the thickness of the substrate, and the ink film such as the pattern layer follows the behavior of the substrate. The base material has a thickness of 100 to 1000 μm, and the thickness that is often used is 150 to 500 μm. The pattern layer is a pattern, a painting, a logo, letters, blank letters,
In order to form a symbol or the like, a translucent ink, a light-shielding ink, or the like is used by a normal forming method such as printing. The pattern layer may have a metal layer formed by vacuum vapor deposition. You may form an adhesive layer as needed.

[0034]

EXAMPLES Examples of a preform film manufacturing apparatus and a preform film manufacturing method according to the present invention will be described. First, the film 5 was placed on the frame-shaped clamp in the gap between the compressed air means 1 and the exhaust means 4 (see FIG. 1). The robot hand 29 was used to mount the film 5. The robot hand 29 moved with the four sides of the film 5 fixed by the suction cups 30. When mounting, the positioning pin 32 formed in the frame-shaped clamp was inserted into the positioning hole formed in two places of the film 5 (refer FIG. 1). The film 5 is made of acrylic resin and has a thickness of 350 μm.
A m-thick base material on which a picture layer and an adhesive layer were sequentially formed was used. The softening temperature of the film 5 was 90 ° C.

Next, the film 5 was sandwiched between the edge of the compressed air means 1 and the frame-shaped clamp (see FIGS. 2 and 9). Figure 1
4 and FIG. 15, the frame-shaped crank 2 is replaced by the pneumatic means 1.
Approach. By this sandwiching, the film 5 is formed into a predetermined ring shape by the opening edge portion 31 of the compressed air means 1 and the frame-shaped clamp.
Are sandwiched (see FIG. 9). The portion of the film 5 that covers the preform mother die 3 is not sandwiched, and the state is like that of a drum. As the frame-shaped clamp, one having a size that can enclose the patterns of four mobile phones arranged in 2 rows and 2 columns formed on the film 5 was used.
At this time, since the discharge hole 60 of the compressed air means 1 was in a sealed state, the film did not sag under its own weight.

Next, the heating portion of the heating means is introduced between the frame-shaped clamp and the preform mother die 3. The entire lower surface of the film was heated by the heating unit (see FIGS. 2 and 10).
This heating was performed above the softening temperature of the film. In this example, since a substrate having a thickness of 350 μm, which was formed by sticking an acrylic resin film and an ABS resin film together, was used, the film was heated with a ceramic heater until the surface temperature of the film reached 120 to 130 ° C. The heating time was 4 to 7 seconds. The distance between the film and the heating part (heater panel) was set to 60 to 40 mm. The film 5 is easily softened because it is heated above its softening temperature, and at the same time, the air in the space 9 sealed by the concave portion of the compressed air means 1 and the film 5 expands so that the film 5 bulges into a convex shape. And However, in order to stop this swelling and keep the film flat, the discharge hole 6 in the sealed state is used.
0 is opened and exhaust is performed. For this exhaust, the valve provided in the exhaust hole 60 is opened, and a device such as a vacuum ejector is used to perform forced exhaust while adjusting the amount of suction to bring the space 9 to a state close to atmospheric pressure. By.

Next, the heating means 10 was retracted from between the frame-shaped clamp and the preform mother die 3 (see FIG. 3). This is to prevent an obstacle when the compressed air means 1 / frame-shaped clamp / preform mother die 3 / exhaust means 4 contact in this order. In order to prevent convection accompanying the movement of the heating means 10 and the wind from hitting the heated film 5 to reduce the temperature of the film 5, the moving speed when the heating means 10 retracts is about 250 cm / Seconds

Next, the compressed air means 1 and the exhaust means 4 are brought close to each other, and the compressed air by the compressed air means 1 is used to form the preform mother die 3.
The film was brought into close contact with the unevenness 7 and the film having a shape along the unevenness 7 of the preform mother die 3 was obtained from the film 5 kept flat (see FIGS. 4, 11, and 12). Even while the compressed air means 1 is close to the exhaust means 4,
By continuing the discharge from the discharge hole 60 of the compressed air means 1, it is possible to prevent the film 5 from bulging in a convex shape,
Film 5 was kept flat. The convex portion of the preform mother die 3 has a three-dimensional shape of the upper lid of the mobile phone and is formed side by side in two rows and two columns (see FIG. 8A). Film 5
After the heating means 10 is retracted after heating the lower surface of the preform, the film 5 can be immediately brought into close contact with the convex portion of the preform mother die 3 without a gap, so that the film 5 can be kept in a sufficiently soft state. I was able to form. The temperature of the film 5 immediately before introducing the compressed air is 13
It was 0 ° C and was sufficiently soft. Therefore, the pneumatic means 1
Compressed air pressure from 2.5MPa, compressed air time is about 4
It took only seconds.

Next, after introducing the compressed air, the compressed air means 1 was started to rise after waiting for about 2 seconds (see FIG. 5). The robot hand 29 described above was used to remove the preformed film 5 from between the air pressure means 1 and the frame-shaped clamp (see FIG. 5). When removing the preformed film 5 with the robot hand 29, the non-preformed film 5 fixed to the suction cup 30 on the surface opposite to the surface to which the preformed film 5 is fixed is placed on the frame-shaped clamp. It was placed.

[0040]

Since the present invention employs the above-mentioned structure, it has the following effects. In the present invention, by discharging the air in the space formed by the concave portion of the compressed air means and the film, a film having a shape along the unevenness of the preforming mother die is obtained from the film in a flat state. Even when the film is heated, it is possible to control the swelling of the film due to the expansion of air in the sealed space, the expansion of the film itself, and the generation of waviness and sagging of the film due to expansion and contraction. Therefore, even if the film is kept at a high temperature, the film and the mold can be accurately aligned. Further, in the present invention, since the film can be heated to the softening temperature or higher, the film can be preformed without any stress remaining inside the film. For this reason, even if an external thermal or physical impact is applied to the film after preform or it is subjected to a change over time, the film is less likely to crack and the film loss is small. Especially in places where the film is bent sharply, it is difficult for the film to have unnecessary broken lines,
Little film loss. Further, a high-voltage generator is not required, there is no danger in handling the high-voltage generator, and there is no cost in terms of safety measures.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a film forming apparatus of the present invention.

FIG. 2 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 3 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 4 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 5 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 6 is a plan view showing an example of heating means of the film forming apparatus of the present invention.

FIG. 7 is a plan view and a cross-sectional view showing an example of a frame-shaped clamp of the film molding apparatus of the present invention.

FIG. 8 is a perspective view and a sectional view showing an example of a preform mother die of the film forming apparatus of the present invention.

FIG. 9 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 10 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 11 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 12 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 13 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 14 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

FIG. 15 is a partial cross-sectional view showing an example of the film forming apparatus of the present invention.

[Explanation of symbols]

1 Pneumatic means 2 Film clamp means 3 Preform parent mold 4 exhaust means 5 films 6 compressed air holes 60 discharge holes 7 convex 8 Air compressor 9 space 90 recess 10 Heating means 11 heater panel 12 Taper pin 13 bush 14 Exhaust hole 15 Frame-shaped clamp support 16 Pneumatic means support 17 heating section 19 hydraulic cylinder 20 posts 22 Drive 23 split heating section 24 Heating means mounting table 25 rails 29 robot hand 30 suckers 31 Opening edge 32 Film positioning pin 33 slits 34 Sheath heater

Claims (7)

[Claims] 1. A heating method in which a film sandwiched by a pneumatic clamping means having a concave portion facing the film and having a pneumatic hole and a discharge hole and a film clamping means is introduced between the film clamping means and the preform mother die. While heating the film above its softening temperature by means, the film was kept flat by discharging the air in the space formed between the concave portion of the compressed air means and the film, and the heating means was retracted. After that, the compressed air means is brought close to the preform mother die, and the space formed between the concave portion of the compressed air means and the film is compressed, so that the film in a flat state is uneven in the preform mother die. A method for producing a preform film, which comprises obtaining a film having a shape according to. 2. The preform film according to claim 1, wherein the space formed between the recess of the air pressure means and the film is kept at the same atmospheric pressure as the atmospheric pressure to keep the film flat. Manufacturing method. 3. A space formed between the recess of the air pressure means and the film is a closed space, and air is forcibly discharged from a discharge hole of the air pressure means to keep the film flat. Item 2. A method for producing a preform film according to item 1. 4. A preform mother die having unevenness placed on the exhaust means, a film clamp means having a frame-shaped clamp capable of approaching and separating from the preform mother die, and facing the film. Pneumatic means having a concave portion and having a pneumatic hole and a discharge hole and capable of approaching and separating from the preform mother die via the film clamping means,
An apparatus for producing a preform film, comprising: a heating means capable of being introduced and retracted between the film clamping means and the preform mother die. 5. The preform film manufacturing apparatus according to claim 4, wherein the exhaust means, the film clamp means, and the compressed air means are arranged in a vertical direction. 6. The apparatus for producing a preform film according to claim 4, wherein the heating means is composed of an assembly of heaters whose temperature can be individually controlled. 7. A robot hand in which a film holding portion for removing a preformed film and a film holding portion for mounting an unpreformed film on a frame-shaped clamp are arranged back to back. The preform film manufacturing apparatus according to any one of claims 4 to 6.