Method of shaping film

Abstract

The present invention provides a method for shaping a film that prevents the formation of air pockets between the film and the substrate while suppressing the occurrence of defects in appearance. [Solution] The method for shaping a film comprises a through-hole forming step S1 in which a resin film having a coating layer and an adhesive layer has multiple through-holes with a diameter of 10 to 50 μm in the thickness direction of the layer; a film heating step S2 in which the film with the through-holes formed is heated; a substrate placement step S3 in which a substrate is placed in a compressed air device; a film placement step S4 in which the heated film is placed on the substrate so that its adhesive layer faces the substrate placed in the compressed air device; and a compressed air forming step S5 in which the film is pressed tightly to the substrate by compressed air forming without vacuuming or heating the film.

Description

Technical Field

[0001] The present invention relates to a method for shaping a film.

Background Art

[0002] Conventionally, in such a technical field, it is known to shape a film made of a thermoplastic resin into a predetermined shape by vacuum forming or pressure-air forming. For example, the film shaping method described in Patent Document 1 includes a step of placing a first substrate (transfer object) on a mounting table having a plurality of suction holes, a step of sequentially covering the first substrate with a second substrate (transfer material) and a film (flexible sheet), sucking air from the suction holes of the mounting table to bring the second substrate into close contact with the first substrate, and a step of heating the second substrate by heat conduction from the film and adhering it to the first substrate. A plurality of fine holes are formed in the second substrate, and when sucking air, the air between the second substrate and the film and the air between the second substrate and the first substrate are excluded through the fine holes formed in the second substrate, preventing the occurrence of incomplete transfer due to air accumulation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the shaping method described in Patent Document 1 above, since it is necessary to form fine holes in the second substrate, it becomes difficult to process the fine holes when the substrate is thick. Also, when sucking air, the film may enter the fine holes of the second substrate, which may cause defects in the appearance of the product.

[0005] The present invention was made to solve these technical problems, and aims to provide a method for shaping a film that can prevent the occurrence of air pockets between the film and the substrate while suppressing the occurrence of defects in appearance. [Means for solving the problem]

[0006] The present invention provides a method for shaping a film, comprising: a through-hole forming step of forming a plurality of through-holes with a diameter of 10 to 50 μm in the thickness direction of a resin film having a coating layer and an adhesive layer; a film heating step of heating the film in which the through-holes have been formed; a film placement step of placing the heated film on a substrate such that the adhesive layer faces the substrate placed in a compressed air device; and a compressed air forming step of pressing the film to the substrate by compressed air forming without vacuuming or heating the film.

[0007] The film shaping method according to the present invention includes a through-hole forming step in which multiple through-holes with a diameter of 10 to 50 μm are formed in the resin film in the thickness direction. This allows air between the film and the substrate to escape using the through-holes, preventing the formation of air pockets between the film and the substrate. In addition, because the diameter of the through-holes is 10 to 50 μm, air between the film and the substrate can escape sufficiently through the through-holes while suppressing the occurrence of appearance defects caused by the formation of the through-holes.

[0008] Furthermore, since it is no longer necessary to form micropores in the substrate as in conventional methods, the phenomenon of the film becoming lodged in the micropores of the substrate, as seen in conventional methods, can be reliably prevented. As a result, it is possible to prevent the formation of air pockets between the film and the substrate while suppressing the occurrence of defects in appearance. Therefore, an improvement in quality can be expected. In addition, since vacuuming and heating of the film are not performed during pressure forming, the cycle time can be shortened, and productivity can be improved.

[0009] Furthermore, since vacuuming and heating of the film are not performed during pressure forming, vacuuming and heating equipment are unnecessary. This makes the structure of the pressure equipment used in the pressure forming process relatively simpler, thus reducing capital investment and lowering manufacturing costs. In addition, since heating of the film is performed in a separate process from the pressure forming process, it becomes possible to optimize the distance between the heating element and the film. As a result, energy loss related to heating can be suppressed. [Effects of the Invention]

[0010] According to the present invention, it is possible to prevent the formation of air pockets between the film and the substrate while suppressing the occurrence of defects in appearance. [Brief explanation of the drawing]

[0011] [Figure 1] This is a flowchart showing the method for shaping the film according to the embodiment. [Figure 2] This is a schematic diagram illustrating the method for shaping the film according to the embodiment. [Figure 3] This is a schematic diagram illustrating the method for shaping the film according to the embodiment. [Figure 4] This is a schematic diagram illustrating the method for shaping the film according to the embodiment. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the film shaping method according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and their redundant descriptions are omitted.

[0013] The film 10 described in this embodiment is also called a sheet and is a multilayer resin film having a coating layer and an adhesive layer. The film 10 is used, for example, as a decorative film and is applied to the surface of products such as automobile parts and personal computers to improve the design and weather resistance of the products.

[0014] The coating layer of film 10 is a layer located on the surface side of film 10, and is coated with a design such as color or pattern. This coating layer is formed in the form of a thin sheet using, for example, polyvinyl chloride resin, amorphous, low-crystalline or crystalline polyester, polyolefins such as polypropylene and polyethylene, styrene-based resins such as acrylonitrile-butadiene-styrene copolymer resin (ABS resin), styrene-ethylene-butadiene-styrene copolymer, acrylonitrile-styrene-acrylic copolymer resin, acrylonitrile-ethylene-propylene-diene-styrene copolymer resin and its hydrogenated products, thermoplastic resins such as polyamide, acrylic, polycarbonate, and polyurethane, and resin compositions containing two or more of these thermoplastic resins.

[0015] On the other hand, the adhesive layer of the film 10 is a layer located on the back side of the film 10 and is formed by applying an adhesive. Examples of adhesives here include acrylic, ethylene vinyl acetate, vinyl acetate, polyester, polyurethane, natural rubber, epoxy resin, polyisobutylene, chloroprene rubber, and styrene-butadiene rubber.

[0016] Figure 1 is a flowchart showing a method for shaping a film according to this embodiment. The method for shaping a film according to this embodiment mainly comprises a through-hole formation step S1, a film heating step S2, a substrate placement step S3, a film placement step S4, a pressure molding step S5, and a product removal step S6.

[0017] In the through-hole formation step S1, multiple through-holes 11 with a diameter of 10 to 50 μm are formed in the film 10 in the direction of its layer thickness. Specifically, as shown in Figure 2(a), fine through-holes 11 are formed in the film 10 using a film hole-punching device 20. The film hole-punching device 20 is, for example, a device having a laser, and by irradiating the strip-shaped film 10, which is conveyed along the direction of the arrow in Figure 2(a), with the laser, multiple through-holes 11 are formed in the film 10 at predetermined intervals.

[0018] The diameter of the through-hole 11 is set to 10 to 50 μm as described above. This is the result of considering that in the subsequent compressed air forming step S5, the air between the film 10 and the base material 50 can sufficiently escape through the through-hole 11 and to prevent the occurrence of appearance defects caused by the formation of the through-hole 11. That is, when the diameter of the through-hole 11 is smaller than 10 μm, the air escape between the film 10 and the base material 50 becomes insufficient, and an air pocket will occur. On the other hand, when the diameter of the through-hole 11 exceeds 50 μm, the through-hole 11 becomes visible, leading to a problem that affects the appearance of the product.

[0019] The cross-section of the through-hole 11 may be circular, polygonal such as square, or elliptical. In the case of a polygon, the distance on the longest diagonal line, and in the case of an ellipse, the major axis thereof, need to be within the range of 10 to 50 μm, respectively.

[0020] In addition, when the film originally has micropores, the through-hole forming step S1 is omitted.

[0021] In the film heating step S2, the film 10 in which the through-hole 11 is formed is heated to a predetermined temperature. Specifically, as shown in FIG. 2(b), while passing the strip-shaped film 10 through the inside of the film heating device 30, the film 10 is heated and plasticized (or softened) by the heater 31 provided inside the film heating device 30.

[0022] The film heating device 30 has, for example, a box shape. There are a plurality of heaters 31, which are attached to the ceiling of the film heating device 30 at a predetermined interval. In the film heating device 30, openings for passing the film 10 are provided in a pair of left and right side wall portions 32 facing each other in the longitudinal direction thereof. Further, outside each side wall portion 32 and near the opening, a plurality of pairs (here, two pairs) of left and right conveying rollers 33 for conveying the film 10 are arranged. Each pair of conveying rollers 33 is a pair of upper and lower ones, and by rotating while applying a predetermined pressure to the film 10 disposed therebetween, the film 10 is conveyed, for example, from the left side to the right side of the drawing.

[0023] In the base material placement step S3, the base material 50 is placed inside the compressed air device 40. As shown in FIG. 2(c), the compressed air device 40 has a lower housing 41 and an upper housing 42 that are relatively movable in the vertical direction. In the present embodiment, the lower housing 41 is the fixed side and the upper housing 42 is the movable side. That is, the upper housing 42 is configured to approach or separate from the lower housing 41 by a driving device (not shown). When the upper housing 42 is brought close to the lower housing 41 and the two are closed (so-called mold clamping), a sealed space is formed inside the compressed air device 40. On the other hand, when the upper housing 42 is separated from the lower housing 41 (so-called mold opening), the base material 50 can be carried into and placed inside the lower housing 41, or the shaped base material 50 (that is, the product) can be taken out.

[0024] Further, the compressed air device 40 is disposed below the lower housing 41 and has a lifting device 44 for lifting and lowering a mounting table 43 provided on the lower housing 41 in the vertical direction. Further, outside the compressed air device 40, a plurality of pairs (here, two pairs) of left and right conveying rollers 45 for conveying the film 10 across the lower housing 41 are disposed. Each pair of conveying rollers 45 is a pair of upper and lower ones, and by rotating while applying a predetermined pressure to the film 10 disposed between them, the film 10 is conveyed, for example, from the left side to the right side of the drawing.

[0025] Then, as shown by the arrow in FIG. 2(c), in the base material placement step S3, with the upper housing 42 separated from the lower housing 41, for example, the base material 50 is carried in from the right side of the lower housing 41, placed on the mounting table 43, and fixed.

[0026] The base material 50 is, for example, an automotive part having a predetermined shape. The base material 50 may be formed of a metal material such as an aluminum alloy or steel, or a resin material. Examples of the resin material include polystyrene-based resins, acrylic-based resins, acrylic-styrene-based resins, polycarbonate-based resins, polyester-based resins, polyamide-based resins, polypropylene-based resins, and polyethylene-based resins.

[0027] In the film placement step S4, the film 10 heated in the film heating step S2 is placed on the substrate 50 located inside the compressed air device 40. Specifically, as shown in Figure 3(a), the heated strip-shaped film 10 is set on the left and right transport rollers 45 so that it crosses over the substrate 50. At this time, the film 10 is set so that its adhesive layer faces the substrate 50.

[0028] In the compressed air forming process S5, first, as shown in Figure 3(b), the upper housing 42 is brought close to the lower housing 41 and closed together. This creates a sealed space inside the compressed air device 40.

[0029] Next, the film 10 is pressed tightly against the base material 50 by pressure forming without vacuuming or heating the film. Specifically, as shown in Figure 4(a), first, the mounting table 43 is raised to push up the base material 50 placed on the mounting table 43 so that the upper surface of the base material 50 is in close contact with the adhesive layer of the film 10. Next, compressed air from the compressed air tank 46 is sent into the compressed air device 40, and pressure is applied to the film 10 from above, further pressing the film 10 tightly against the base material 50. At this time, the air between the film 10 and the base material 50 is vented through the through holes 11 formed in the film 10. As a result, the film 10 adheres tightly to the upper surface of the base material 50 while conforming to the shape of the upper surface of the base material 50.

[0030] In the product removal process S6, the film 10, which is in close contact with the base material 50, is cooled to solidify. After the film 10 has solidified, the upper housing 42 is separated from the lower housing 41, the film 10 in close contact with the base material 50 is cut from the strip-shaped film 10, and the base material 50 (product) after pressure molding is removed from the lower housing 41.

[0031] The film shaping method according to this embodiment includes a through-hole forming step S1 in which a plurality of through-holes 11 with a diameter of 10 to 50 μm are formed in the resin film 10 in the thickness direction of the layer. Therefore, in the pressure forming step S5, the through-holes 11 can be used to release the air between the film 10 and the substrate 50, preventing the formation of air pockets between the film 10 and the substrate 50. In addition, since the diameter of the through-holes 11 is 10 to 50 μm, the air between the film 10 and the substrate 50 can be sufficiently released through the through-holes 11, while preventing the occurrence of appearance defects caused by the formation of the through-holes 11.

[0032] Furthermore, since it is no longer necessary to form micropores in the substrate as in the conventional method, the phenomenon of the film becoming lodged in the micropores of the substrate can be reliably prevented. As a result, it is possible to prevent the formation of air pockets between the film 10 and the substrate 50 while suppressing the occurrence of defects in appearance. Therefore, an improvement in quality can be expected. In addition, since vacuuming and heating of the film are not performed in the pressure forming process S5, the cycle time can be shortened, and productivity can be improved.

[0033] Furthermore, since vacuuming and heating of the film are not performed in the pressure forming process S5, vacuuming equipment and heating equipment become unnecessary. As a result, the structure of the pressure device 40 used in the pressure forming process S5 becomes relatively simple, which reduces capital investment and lowers manufacturing costs. In particular, when vacuuming is required, the equipment becomes larger in order to ensure the rigidity of the pressure device that can withstand the vacuum. Eliminating the need for vacuuming allows for simplification of the equipment.

[0034] Furthermore, when a heating device (heater) is attached to a compressed air device, it is necessary to secure space to push up the substrate, which increases the distance between the heater and the film, leading to a problem of increased energy loss related to heating. In this embodiment, heating of the film 10 is performed by a dedicated film heating device 30 rather than the compressed air device 40, making it possible to optimize the distance between the heater 31 and the film 10. As a result, energy loss related to heating can be suppressed.

[0035] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. [Explanation of Symbols]

[0036] 10: Film, 11: Through hole, 20: Film punching device, 30: Film heating device, 31: Heater, 32: Side wall, 33: Conveyor roller, 40: Compression device, 41: Lower housing, 42: Upper housing, 43: Mounting platform, 44: Lifting device, 45: Conveyor roller, 46: Compression tank, 50: Substrate

Claims

[Claim 1] A method for shaping a film, A through-hole forming step is performed on a resin film having a coating layer and an adhesive layer, in which multiple through-holes with a diameter of 10 to 50 μm are formed in the thickness direction of the layer, A film heating step in which the film in which the through holes are formed is heated, A film placement step involves placing the heated film on the substrate such that the adhesive layer faces the substrate placed inside the compressed air device, A pressure forming process in which the film is pressed tightly against the substrate by pressure forming without vacuuming or heating the film, A method for shaping a film, characterized by comprising the following:

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