JP3916983B2 - Method for producing preform film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention integrates a film on the surface of a three-dimensional molded product that rises, such as buttons, knobs, shift lever housings, etc. used in mobile phone cases, automotive instrument panels, heat-con panels, center panels, and those panels. The present invention relates to a preform film manufacturing method and a preform film manufacturing apparatus. In addition, a preform means shape | molding a film in the solid | 3D shape substantially matched with the shape of the cavity formation surface of an injection mold.
[0002]
[Prior art]
Conventionally, a preform film manufacturing method has been as follows.
(1) The film is sandwiched in the opening edge of the concave portion of the air pressure means, the film is heated in advance to its softening temperature, and the film is brought into close contact with the mold for preforming by pressure forming to deform the film into a predetermined three-dimensional shape. There is a method of forming by cooling the film and maintaining its three-dimensional shape.
(2) The film is sandwiched in the opening edge of the recess of the compressed air means, and the film is brought into close contact with the preform mold by high-pressure compressed air molding without preheating the film to its softening temperature, and the film has a predetermined three-dimensional shape. There is a method in which the film is formed by cooling the film and maintaining its three-dimensional shape.
[0003]
[Problems to be solved by the invention]
However, in the method (1), since the film is heated after the opening edge of the concave portion of the compressed air means having the concave portion is sandwiched, the air in the space sealed by the concave portion of the compressed air means and the film expands. As a result, the film swells, and the film itself swells and the film undulates and sags due to expansion and contraction. As a result, alignment between the film and the preform mold cannot be performed with high accuracy.
In the method (2), since the film is not heated, the film is deformed into a three-dimensional shape while the stress remains in the film. As a result, a thermal and physical impact from the outside is applied after the deformation, or a change with time is easily caused, so that a crack is easily generated in the film and a film loss is large. In addition, the surface of the film is easily damaged at the corners of the preform mold when compressed. Particularly in places where the film is bent sharply, useless broken lines are attached to the film, resulting in a large film loss. In addition, a high-pressure generator is required, the danger of handling the high-pressure generator increases, and the cost of the apparatus is high in terms of safety measures.
The present invention overcomes the drawbacks of these prior arts, enables highly accurate alignment between the film and the preform mold, and reduces the film loss and the like. An object is to provide a manufacturing apparatus.
[0004]
[Means for Solving the Problems]
The method for producing a preform film according to the present invention includes a film clamp means, a preform mold, and a film sandwiched between a pressure air means having a concave portion facing the film and a pressure air hole and a discharge hole, and a film clamp means. While heating the film above its softening temperature by the heating means introduced during the period, the film was kept 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 matrix, 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 from the pre-formed film. A film having a shape along the irregularities of the matrix for foam is obtained. In the preform film manufacturing method of the present invention, the space formed between the concave portion of the compressed air means and the film is always kept the same as the external air pressure so that the film is kept flat. You can also. In the preform film manufacturing method of the present invention, the space formed between the concave portion of the compressed air means and the film is set as a sealed space, and air is forcibly discharged from the discharge hole of the compressed air means. It can also be kept flat.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
For convenience of explanation, first, the preform film manufacturing apparatus of the present invention will be described.
The preform film manufacturing apparatus according to the present invention comprises a preform mold having projections and depressions placed on an exhaust means, and a film clamp means having a frame-like clamp capable of approaching and separating from the preform mold. A pressure air means having a concave portion facing the film, a pressure air hole and a discharge hole, and capable of approaching / separating from the preform die via the film clamp means, a film clamp means and a preform mother And a heating means that can be introduced into and withdrawn from the mold.
[0006]
For convenience of explanation, the compressed air means 1 will be described.
The compressed air means 1 presses air against the film 5 to bring the film 5 into close contact with the irregularities 7 of the preform matrix 3 without any gaps, thereby obtaining a film 5 having a shape along the irregularities 7 of the preform matrix 3. Is for. The compressed air means 1 has a recessed portion 90 facing the film 5, and has a compressed air hole 6 and a discharge hole 60, and can be approached and separated from the preform mother die 3 through the film clamp means 2. . The compressed air means 1 has a function of sandwiching the film 5 in the opening edge 31 of the recess 90 in cooperation with the film clamp means 2. The compressed air means 1 has a function of introducing compressed air from the compressed air holes 6 into the recesses 90 of the compressed air means 1 after contacting the exhaust means 4 with the film clamp means 2 interposed therebetween. As the compressed air means 1, there is a device generally used for air blow molding.
[0007]
The compressed air means 1 has a compressed air hole 6 on the wall surface forming the recess 90. The pressure 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 compressor 8, the space 9 formed by the concave portion 90 of the compressed air means 1 and the film becomes high pressure. The pressure for creating compressed air is preferably 1 Mpa to 5 Mpa. In this invention, since the film 5 can be stretched while the film 5 is heated to a high temperature, the film 5 can be brought into close contact with the preform matrix 3 even at a relatively low pressure. As a set value of pressure for generating compressed air, when using a laminated film of an ABS resin film and an acrylic resin film and having a total thickness of 500 μm, a set value of 2 MPa at a heating temperature of 250 ° C. is preferable. In the case of a polycarbonate resin film having a thickness of 200 μm, a setting value of 4.5 MPa is preferable at a heating temperature of 250 ° C.
[0008]
The compressed air means 1 has a discharge hole 60 in the wall surface forming the recess 90. The discharge hole 60 kept the film 5 flat by discharging the air in the space 9 when the film sandwiched in the opening edge portion 31 of the concave portion 90 of the compressed air means 1 was heated above its softening temperature. It is a hole for making a state. When the space 9 is at or above atmospheric pressure, the space 9 can be reduced to atmospheric pressure by opening the valve of the discharge hole 60. When 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 greatly exceeds the atmospheric pressure, not only the valve of the discharge hole 60 is opened but also the air can be forcibly discharged.
[0009]
Examples of the material of the main body constituting the compressed air means 1 include iron, aluminum, copper, nickel and alloys based on them, or epoxy resin containing metal powder. The reason for selecting these materials is that the main body constituting the compressed air means 1 needs to be strong enough to withstand the pressure caused by the introduction of compressed air.
[0010]
As the film clamping means 2, there is a frame-shaped clamp. The frame-shaped clamp sandwiches the film 5 in cooperation with the pneumatic unit 1 and moves toward the preform matrix 3 (see FIG. 7).
[0011]
The frame-shaped clamp includes 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, and the film 5 may be sandwiched between the two clamps (not shown). In this case, since the predetermined annular portion of the film 5 is sandwiched, even when the film 5 is misaligned, contracted, or stretched due to the heating of the heating means 10, it can be minimized.
[0012]
The frame clamp may be separable (not shown). For example, there is a square frame-shaped clamp without a cut before division, and two clamp pieces having a U-shape after division. The frame-shaped clamp may be attached with a heater device for clamping or a temperature control circuit (not shown) using a heated fluid medium. The reason for this is that the temperature distribution of the film 5 becomes non-uniform due to the heat of the film 5 being taken away by the frame-shaped clamp, and the film 5 is stretched when closely contacting the irregularities of the preform matrix 3 without gaps. This is to prevent the portions having a low degree of stretching from being broken and the portions having a high degree of stretching from becoming wrinkles. Moreover, only the part where the temperature of the film 5 tends to decrease can be preheated strongly. As the heater for the clamp, there is a rod-shaped sheathed heater 34 or the like, which is preferably embedded in four pieces of the frame-shaped clamp (FIGS. 7A and 7B). The temperature control circuit has a structure in which heated water is drawn into the frame clamp from an external device that can control the temperature by heating a fluid medium such as water or oil, and circulates in the frame clamp. There are things.
[0013]
The frame clamp may have a bush 13 that matches the taper pin 12 formed on the upper surface of the exhaust means 4 (see FIGS. 7A and 7B and FIGS. 9 to 13). This is to prevent the unevenness 7 of the preform matrix 3 and the film 5 from being misaligned when the frame clamp, preform preform 3 and exhaust means 4 come into contact with each other. The bush 13 is preferably formed at least in the center of two opposing sides of the frame-shaped clamp.
[0014]
The frame-shaped clamp may have two or more film positioning pins 32 on its upper surface (see FIG. 7B and FIGS. 9 to 13). This is to prevent the frame clamp and the film 5 from being misaligned. The taper pin 12, the bush 13, and the film positioning pin 32 can prevent the unevenness of the preform matrix 3 and the film 5 from being misaligned. The number of film positioning pins 32 is 2 or more, preferably 4-8. This is to minimize the positional deviation in the left / right, up / down, and rotational directions. The location where the film positioning pin 32 is formed is preferably the center or corner of each side of the frame clamp. The length of the film positioning pin 32 is preferably 5 to 10 mm. The diameter of the film positioning pin 32 is preferably 2 to 8 mm.
[0015]
The preform mold 3 is for pre-forming the film 5 into a three-dimensional shape that matches the shape of the cavity forming surface of an injection mold described later by closely contacting the film 5 to the surface thereof. (See FIG. 8). The preform matrix 3 may be provided with a small hole in the vicinity of the convex portion or connected to the exhaust hole 14 or may be formed with a slit 33 (see FIG. 8), or a fine passage through which air passes. The protrusions themselves may have pores. Examples of the projection itself having a fine ventilation hole through which air passes include a porous metal and a porous ceramic. Examples of the material for the preform matrix 3 include iron, aluminum, copper, nickel, alloys based on these, and epoxy resins containing metal powder. The surface of the preform matrix 3 may be coated with a fluorine resin, a silicone resin, or the like.
[0016]
The preform matrix 3 may have a plurality of convex portions (see FIG. 8). For example, a plurality of convex portions have a three-dimensional shape of an upper lid of a mobile phone, and are formed in two rows and two columns (see FIG. 8A). Further, in order to prevent air leakage and to ensure exhaust from the exhaust hole 14, there is one having a rise at the edge of the preform mother die 3 (see FIGS. 8B, 14 and 15). . Each convex part may exhibit the three-dimensional shape of the upper lid of the same mobile phone. The plurality of convex portions may have different three-dimensional shapes.
[0017]
The evacuation unit 4 is configured such that the compressed air unit 1 comes into contact with the evacuation unit 4 and the film 5 covers the unevenness 7 of the preform mother die 3, and then the gap between the unevenness 7 of the preform mother die 3 and the film 5 is reduced. The air is exhausted from the exhaust holes 14 to obtain the film 5 having a shape along the irregularities 7 of the preform matrix 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 to prevent the unevenness 7 of the preform matrix 3 and the film 5 from being misaligned when the frame clamp, preform preform 3 and exhaust means 4 come into contact with each other.
[0018]
The relationship of each component other than the heating means 10 in this embodiment is as follows (see FIGS. 1 to 5 and FIGS. 9 to 13).
The preform matrix 3 is fixed on the exhaust means 4 with bolts or the like. A frame-like clamp is installed above the preform matrix 3. The frame-shaped clamp is supported by a frame-shaped clamp support portion 15 and can be moved between the compressed air means 1 and the exhaust means 4 in a mold open state by a hydraulic cylinder or an air cylinder. Further, the compressed air means 1 is attached to the compressed air means support portion 16 and is on standby with a certain distance from the exhaust means 4. This interval may be an interval at which the robot hand can enter when a robot hand to be described later enters. The compressed air means 1 opens and closes with the exhaust means 4 by a hydraulic cylinder 19 attached to the compressed air means support 16.
[0019]
The heating means 10 enters between the frame-shaped clamp and the preform mold 3 and heats from the lower surface of the film 5 sandwiched between the compressed air means 1 and the film clamp means 2, and then the frame-shaped clamp and the preform. It is possible to retreat from the mother die 3 (see FIGS. 1 to 6). An example of the heating means 10 includes a heating unit 17 and a driving unit 22. The heating unit 17 has 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 the heater is cast in a ceramic plate, or a pipe heater. The heating unit 17 can simultaneously heat the film 5 and the preform matrix 3. The heating unit 17 may include a plurality of divided heating units 23 (a heater panel is divided into four) that can be individually controlled in temperature (see FIG. 6). In the case where the preform matrix 3 described above has a plurality of convex portions, one divided heating unit 23 can correspond to one convex portion. Moreover, the temperature setting of the division | segmentation heating part 23 corresponding to the convex part with a big rise of a solid shape can be made high, and the temperature setting of the division | segmentation heating part 23 corresponding to the convex part with a small rise of a solid shape can be made low. Moreover, while setting the temperature setting of the division heating part 23 corresponding to the part of the film in which the picture layer having a large film thickness is formed, the division heating corresponding to the part of the film such as the extraction window part where the picture is not formed. The temperature setting of the part 23 can be lowered. The driving unit 22 introduces the heating unit 17 between the compressed air means 1 and the preform mother die 3 or retracts 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. Examples of the drive unit 22 include a rodless cylinder or the like that uses a driving force of an actuator by air. Alternatively, a 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 a rail 25 on which the drive unit 22 moves.
[0020]
The injection mold having a cavity forming surface that matches the three-dimensional shape of the convex portion of the preform 3 is formed by closing a male mold and a female mold to form a desired three-dimensional molded product. For forming a cavity (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 the three-dimensional shape of the cavity forming surface, there is a three-dimensional shape of the upper lid of the mobile phone.
[0021]
The film forming apparatus according to the present invention also includes a film holder for removing the preformed film 5 from the gap between the compressed air means 1 and the frame-shaped clamp, and a film 5 that is not preformed placed on the frame-shaped clamp. You may have the robot hand 29 arrange | positioned back and back with the film holding part for placing (refer FIG.1, FIG.5, FIG.14).
[0022]
Hereafter, the manufacturing method of the preform film of this invention is demonstrated.
The method for producing a preform film according to the present invention includes a film clamp means, a preform mold, and a film sandwiched between a pressure air means having a concave portion facing the film and a pressure air hole and a discharge hole, and a film clamp means. While the film is heated above its softening temperature by the heating means introduced during the period, air in the space formed between the recess of the compressed air means and the film is discharged to keep the film flat. After the heating means is retracted, the compressed air means is brought close to the preform mold, and the space formed between the concave portion of the compressed air means and the film is compressed to remove the pressure from the film in a flat state. A film having a shape along the irregularities of the preform matrix is obtained.
[0023]
First, the film is sandwiched between the compressed air means and the film clamp means 2.
That is, after the film is placed on the frame-shaped clamp (see FIGS. 1 and 14), the frame-shaped clamp is pushed up by a hydraulic cylinder or the like, and the frame-shaped clamp comes into contact with the opening edge portion 31 of the compressed air means. The film 5 is sandwiched between 1 and the frame-shaped clamp (see FIGS. 1, 2, 9, and 15). In order to place the film on the film clamping means 2, a film may be fed one by one using a robot (see FIG. 1), or a long film wound in a roll shape. May be continuously fed using the rotational force of the roll. The compressed air means 1 moves along the posts 20 provided in four directions via the compressed air means support portion 16.
[0024]
Next, a heating means is introduced between the film clamp means 2 and the preform matrix 3 (see FIGS. 2 and 15). That is, the heating unit 17 of the heating unit is introduced into a position that covers the film 5 sandwiched between the compressed air unit 1 and the frame-shaped clamp. The distance between the heating unit 17 and the film 5 can be expanded or contracted by pushing down the compressed air means 1 with a hydraulic cylinder. The heating unit 17 of the heating unit may enter the frame of the frame-shaped clamp so as not to 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 matrix 3. Alternatively, before the heating means 10 is introduced between the film clamping means 2 and the preform mother die 3, the discharge hole 60 of the compressed air means 1 is sealed and opened during heating. Good. When the discharge hole 60 is in a sealed state, it is effective because the film 5 is unlikely to hang down due to its own weight.
[0025]
Next, while heating the film 5 to the softening temperature or higher by the heating means 10, the film 5 is kept flat by discharging the air in the space 9 formed by the concave portion of the compressed air means and the film 5. (See FIG. 3). The softening temperature of the film 5 is a value measured according to JIS K7206 and ISO306. When the film 5 is heated, the air in the space 9 formed by the concave portion 90 of the compressed air means 1 and the film 5 is also heated, and the volume in the space tends to expand. For this reason, the film 5 sandwiched between the compressed air means 1 and the film clamp means 2 tends to swell into a convex shape. In the present invention, in order to prevent the film 5 from bulging into a convex shape even when the film 5 is heated above the softening temperature, or to return to a flat state even if the film 5 bulges once into the convex shape, the space 9 The air inside is exhausted. Specifically, by keeping the inside of the space 9 always the same as the outside air pressure, the air to be expanded in the space 9 is discharged from the discharge hole 60 of the compressed air means 1 and the film 5 is kept flat. You may make it do. Alternatively, the space 9 may be a sealed space, and the air to be expanded 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 compressed air means 1 is opened, the atmospheric pressure in the space 9 can be reduced to atmospheric pressure. After the heating means is retracted, 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 brought close to the preform mother die 3, so that the degree of opening of the valve In addition, the strength of forced discharge can be reduced to balance the pressure in the sealed space 9 and the wind pressure. While the film 5 sandwiched between the pressure air means 1 and the frame-shaped clamp is being brought close to the preform mother die 3, wind pressure is applied to the film 5, so that the film 5 is unlikely to be convex. Because.
[0026]
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 to make the preform 5 from the film 5 kept flat. A film having a shape along the unevenness is obtained.
That is, after the heating means is retracted from between the compressed air means and the preform mother die 3 (see FIG. 3), the compressed air means 1 is further pushed down by the hydraulic cylinder 19 so that the frame clamp is lowered 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 means 1 is further pushed down by the hydraulic cylinder 19, the pneumatic means 1 / film 5 / frame clamp / preform preform 3 / exhaust means 4 are arranged and contacted in this order (see FIGS. 4 and 12). . The film 5 may be in a state in which a so-called tent is stretched by covering the convex portion of the preform mother die 3, or as shown in FIG. 8 (b), the convex portion of the preform mother die 3 and the film 5 There may be a state in which there is an interval between them.
[0027]
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, the film 5 may be heated to a temperature 5 to 10 ° C. higher than the softening temperature before the heating means is retracted. In this way, even when the rise 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, and the irregularities 7 of the preform mother die 3 are aligned. A film 5 having a shape can be obtained. In addition, the film 5 can be brought into close contact with the preform matrix 3 without any gap in a state where no stress remains in the film 5. Further, no cracks or cloudiness occur on the surface of the film 5. Furthermore, the quality of the film 5 after molding becomes stable.
[0028]
Next, compressed air is introduced into the space 9 from the compressed air hole 6 of the compressed air means 1 to press the film 5 against the convex portion of the preform mother die 3, and the film 5 and the preform are pressed from the exhaust hole 14 of the exhausted means 4. The air in the gap with the mother die 3 is pushed out, and the film 5 is brought into close contact with the preform mother die 3 without any gap (see FIGS. 4 and 12). Air may be forcibly exhausted from the exhaust hole 14 of the exhaust means 4.
[0029]
Next, the compressed air state is maintained until the film 5 is pressed against the irregularities 7 of the preform mother die 3 and the deformation is completed, and then the air in the space 9 is exhausted.
[0030]
Next, the pneumatic means 1 is raised by the hydraulic cylinder 19 to a fixed position of the frame clamp. When the compressed air means 1 is further raised, the frame-shaped clamp is stopped at a fixed position, and only the compressed air means 1 can be further raised (see FIGS. 5 and 13). The compressed air means 1 / frame clamp / preform mold 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 to raise only the compressed air means 1 so that 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-shaped clamp while the frame-shaped clamp is in contact with the exhaust means 4 are performed. (See FIG. 14).
[0031]
There are the following methods for removing the preformed film 5 from between the compressed air means 1 and the frame-shaped clamp. As shown in FIG. 5, there is a method of removing the preformed film 5 with a robot hand or the like after the frame clamp is pulled away from the exhaust means 4. 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 clamp is in contact with the exhaust means 4. When the surface of the preform matrix 3 is coated with a fluorine-based resin, a silicone resin, or the like, the film that is in close contact with the surface of the preform matrix 3 is peeled off from the surface of the preform matrix 3. Because it is easy, it is effective.
[0032]
In addition, as the film 5 used for carrying out the present invention, there is a film (not shown) in which a picture layer on which a picture is formed, an adhesive layer, and the like are sequentially formed on a base material. The base material is a laminated film obtained by laminating a simple substance such as acrylic resin, polypropylene resin, polystyrene resin, ABS resin, polycarbonate resin, polyester resin or a film composed of two or more of these, or a polymer of polycarbonate resin and polybutylene terephthalate resin. There are alloys and polymer alloys of polycarbonate resin and ABS resin.
[0033]
The softening temperatures of the various substrates are as follows.
The acrylic resin is about 110 ° C., the polypropylene resin is about 80 ° C., the polystyrene resin is about 70 ° C., the ABS resin is about 80 ° C., and the polycarbonate resin is about 140 ° C. The softening temperature in the case of a laminated film obtained by laminating two or more kinds of 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 polycarbonate resin and polybutylene terephthalate resin is about 120 ° C. The softening temperature of the polymer alloy of polycarbonate resin and ABS resin is about 100 ° C. In addition, you may think that the softening temperature of the film in which the pattern layer etc. were formed is the same as the softening temperature of the said base material. The reason is that the thickness of the ink film such as the picture layer is extremely thin compared with the thickness of the base material, and the ink film such as the picture layer follows the behavior of the base material. The substrate has a thickness of 100 to 1000 [mu] m, but particularly frequently used is 150 to 500 [mu] m. The pattern layer is formed by a normal forming method such as printing using translucent ink or light-shielding ink to form patterns, paintings, logos, letters, letters, symbols, symbols, etc. on the surface of the three-dimensional molded product. Is done. The picture layer may have a metal layer formed by vacuum deposition. An adhesive layer may be formed as necessary.
[0034]
【Example】
Examples of the preform film manufacturing apparatus and preform film manufacturing method of the present invention will be described.
First, a film 5 was placed on a frame clamp in the gap between the compressed air means 1 and the exhaust means 4 (see FIG. 1). A robot hand 29 was used to place the film 5. The robot hand 29 moved with the suction cup 30 fixing the four sides of the film 5. When mounting, the positioning pin 32 formed in the frame clamp was inserted in the positioning hole formed in two places of the film 5 (refer FIG. 1).
As the film 5, a film in which a picture layer and an adhesive layer were sequentially formed on a 350 μm-thick base material made of an acrylic resin was used. The softening temperature of the film 5 was 90 ° C.
[0035]
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). In the case of FIGS. 14 and 15, the frame-like crank 2 is brought closer to the compressed air means 1. By this sandwiching, the film 5 is sandwiched between the opening edge 31 of the compressed air means 1 and the frame-shaped clamp in a predetermined annular shape (see FIG. 9). The portion of the film 5 that covers the preform matrix 3 is not sandwiched, and the drum 5 is in a state of being covered with a drum. As the frame-shaped clamp, one having a size that encloses the pattern of four mobile phones arranged in two rows and two 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 hang down due to its own weight.
[0036]
Next, a heating part of a heating means is introduced between the frame 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 base material having a thickness of 350 μm made of a laminate of an acrylic resin film and an ABS resin film was used, heating was performed using a ceramic heater until the surface temperature of the film reached 120 to 130 ° C. The heating time was 4-7 seconds. The distance between the film and the heating part (heater panel) was 60 to 40 mm. Since the film 5 is heated above its softening temperature, the film 5 is easily softened, and 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 expands into a convex shape. And However, in order to stop the swelling and keep the film flat, the exhausted hole 60 in the sealed state is opened to perform exhaust. For this exhaust, the valve provided in the exhaust hole 60 is opened, and a vacuum ejector or the like is used to forcibly exhaust the air while adjusting the suction amount so that the space 9 is close to atmospheric pressure. To do.
[0037]
Next, the heating means 10 was retracted from between the frame-shaped clamp and the preform matrix 3 (see FIG. 3). This is to prevent an obstacle when the compressed air means 1 / frame clamp / preform mold 3 / exhaust means 4 contact in this order. In order not to cause convection with the movement of the heating means 10 and wind to hit the heated film 5 to cause a temperature drop of the film 5, the moving speed when the heating means 10 is retracted is about 250 cm / second. Seconds.
[0038]
Next, the compressed air means 1 and the exhaust means 4 are brought close to each other, and the film is brought into close contact with the unevenness 7 of the preform mother die 3 by the compressed air by the compressed air means 1, and the preform mother die is changed from the film 5 in a flat state. The film of the shape along 3 unevenness | corrugations 7 was obtained (refer FIG.4, FIG.11, FIG.12). Even while the compressed air means 1 is approaching the exhaust means 4, by continuing the discharge from the discharge hole 60 of the compressed air means 1, the film 5 is stopped from expanding into a convex shape, and the film 5 is flattened. Kept. The convex portion of the preform mother die 3 is a three-dimensional shape of the upper lid of the mobile phone, and is formed in two rows and two columns (see FIG. 8A). After heating the lower surface of the film 5, as soon as the heating means 10 is retracted, the film 5 can be brought into close contact with the convex portion of the preform mold 3 without any gaps, so that the film 5 is kept sufficiently soft. I was able to preform. The temperature of the film 5 immediately before introducing the compressed air was 130 ° C. and was sufficiently soft. For this reason, the pressure of the compressed air from the compressed air means 1 was 2.5 MPa, and the compressed air time was about 4 seconds.
[0039]
Next, after the introduction of the compressed air, about 2 seconds were waited, and then the pressure means 1 started to rise (see FIG. 5). In order to remove the preformed film 5 from between the compressed air means 1 and the frame-shaped clamp, the robot hand 29 described above was used (see FIG. 5). When the film 5 preformed by the robot hand 29 is removed, the non-preformed film 5 fixed to the suction cup 30 opposite to the surface on which the preformed film 5 is fixed is placed on the frame clamp. It was placed.
[0040]
【The invention's effect】
In this invention, since the above configuration is adopted, the following effects can be obtained. In this 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 irregularities of the preform matrix is obtained from the film in a flat state. Even when the film is heated, it is possible to control the occurrence of swelling of the film due to the expansion of air in the sealed space, the swelling of the film itself, the waviness of the film due to expansion and contraction, and the sag. For this reason, even if the film is kept at a high temperature, the film and the mold can be aligned with high accuracy.
Moreover, in this invention, since a film can be heated more than softening temperature, a film can be preformed, without a stress remaining in a film inside. For this reason, even if a thermal or physical impact from the outside is applied after the preform or a change with the passage of time is not caused, the film is hardly cracked, and the film loss is small. In particular, even when the film is bent sharply, it is difficult for the film to have an unnecessary broken line, so there is little film loss. In addition, no high pressure generator is required, there is no danger in handling the high pressure generator, and there is no equipment cost in terms of safety measures.
[Brief description of the 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.
7A and 7B are a plan view and a cross-sectional view showing an example of a frame-shaped clamp of the film forming apparatus of the present invention.
FIGS. 8A and 8B are a perspective view and a cross-sectional view showing an example of a preform die for the film forming apparatus of the present invention. FIGS.
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 clamping means
3 Preform matrix
4 Exhaust means
5 films
6 Pressure hole
60 discharge hole
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 clamp support
16 Pneumatic means support part
17 Heating part
19 Hydraulic cylinder
20 posts
22 Drive unit
23 Division heating unit
24 Heating means mounting table
25 rails
29 Robot Hand
30 sucker
31 Opening edge
32 Film positioning pins
33 slit
34 Seeds heater

Claims (3)

  The film sandwiched between the pressure clamping means and the film clamping means having a concave portion facing the film and having a pressure hole and a discharge hole and the film clamping means are heated by a heating means introduced between the film clamping means and the preform mold. While heating above the softening temperature, the film is kept flat by discharging the air in the space formed between the concave portion of the compressed air means and the film. By approaching the preform matrix and compressing the inside of the space formed between the concave portion of the compressed air means and the film, the shape of the preform along the irregularities of the preform matrix is maintained from the flat film. A method for producing a preform film, comprising obtaining a film.   The method for producing a preform film according to claim 1, wherein the space formed between the concave portion of the compressed air means and the film is always the same as the external air pressure so that the film is kept flat.   The space formed between the concave portion of the compressed air means and the film is set as a sealed space, and air is forcibly discharged from the discharge hole of the compressed air means to keep the film flat. A method for producing a preform film.

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