JP2000052416A - Film insert molding method and preforming mold used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film insert molding method high in the non-defective ratio of a molded product and excellent in productivity and economical efficiency. SOLUTION: In a film insert molding method wherein a preformed insert film cut into a predetermined shape is fed into an injection mold to be fixed and the injection mold is closed to fill the cavity of the mold with a molten resin, the electric heater 3 coming into contact with the insert film 2 along the cutting scheduled line thereof at a time of the completion of preforming is preliminarily provided to a preforming mold 1 and, by supplying a current to the electric heater 3 in such a state that the insert film 2 is preformed on the preforming mold 1, the insert film 2 is burnt off at the part coming into contact with the electric heater 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automobile interior parts such as console panels, center clusters and switch bases, automobile exterior parts such as wheel caps and malls, building materials such as walls and pillars, rice cookers and washing machines, and the like. The present invention relates to a film insert molding method applied to the manufacture of home electric appliance parts such as display panels, and a preforming mold used for the method.

[0002]

2. Description of the Related Art Conventionally, as a method of painting a surface of a resin molded article, an insert film 2 having a pattern layer or the like formed on a base film is preformed and cut into a predetermined shape (FIG. 6). ), Transported and fixed in the mold for injection molding, closed the mold, filled the molten resin in the cavity of the mold for injection molding, and attached an insert film to the surface of the molded product at the same time as molding. If the insert film 2 is a transfer film, only the base film of the insert film 2 integrated with the surface of the molded product after the mold opening or simultaneously with the mold opening is peeled off. There has been a method in which a transfer layer such as a layer is left on the molded product side.

[0003] In order to cut the preformed insert film, means such as punching, NC cutting, and laser cutting have been used.

[0004]

However, the above-mentioned cutting means has the following problems 1) to 3).

[0005] 1) In the punching, since the entire tip of the punching blade 7 is pressed against the surface of the insert film to be cut, when cutting along the cut line of the preformed insert film, the cut position is set. The punching blade 7 must be manufactured in consideration of the film shape (see FIG. 7). That is, it is necessary to manufacture the punching blade 7 while cutting the tip of the blade by trial and error, but this is not easy, and the obtained punching blade 7 is expensive.

[0006] 2) In punching and NC cutting, since chips are generated from the cut surface at the time of cutting, the chips adhere to the cut insert film, and as a result, defective products in which the chips are attached to the surface of the molded product are generated. I do.

[0007] 3) In the NC cut and the laser cut, cutting is performed by moving a cutter which contacts a part of the preformed insert film or a laser beam which is focused and irradiated at one point along a predetermined shape. It takes time according to the total length to be cut. In addition, equipment such as a computer for numerically controlling the position, a robot for precisely moving the cutter and the laser irradiating unit, and the like are required, and the cost is high.

[0008] Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a film insert molding method which has a high yield rate of molded articles, and is excellent in productivity and economy.

[0009]

In order to achieve the above-mentioned object, the present invention provides an insert film which is preformed and cut into a predetermined shape, is conveyed and fixed in an injection mold, and then closed. In the film insert molding method in which the molten resin is filled in the cavity of the injection molding die, an electric heating element that comes into contact with the preforming completion along the cut line of the insert film is provided in the preforming mold,
By supplying electricity to the electric heating element in a state where the insert film is preformed on the preforming mold, the portion of the insert film that is in contact with the electric heating element is burned off.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the film insert molding method of the present invention will be described in detail with reference to the drawings.

FIGS. 1, 4 and 5 are sectional views showing an embodiment of a means for preforming and cutting an insert film according to the present invention, and FIG. 2 is a preforming mold provided with an electric heating element according to the present invention. FIG. 3 is a view showing one embodiment of the present invention, and FIG. 3 is a view showing one embodiment of an installation state of an electric heating element according to the present invention in a preforming mold. In the drawing, 1 is a preforming mold, 2 is an insert film, 3 is an electric heating element, 4 is a clamp, 5 is a heater, 6 is a vacuum pump, and 7 is an electric insulating material.

The cutting means of the present invention is the electric heating element 3 provided on the preforming mold 1, and the electric heating element 3 is energized while the insert film 2 is preformed on the preforming mold 1. Thus, the portion of the insert film 2 that comes into contact with the electric heating element 3 is burned off.

Here, the preforming mold 1 has a shape that substantially matches the portion of the cavity forming surface of the injection molding die on which the insert film 2 is disposed, or has a shape in which the irregularities are opposite to the shape. It is a mold having a molding surface and also a support for the insert film 2 in the cutting process. As a material of the preforming mold 1, a metal such as iron, chromium, nickel, or an alloy thereof is preferable because heat resistance is required. Further, in the preforming mold 1, it is preferable to bury a heat insulating material 7 such as mica at a position where the electric heating element 3 is arranged (see FIG. 1).

As a material of the electric heating element 3, a material which has electric resistance, generates Joule heat when a voltage is applied, and can be easily arranged along the three-dimensional shape of the molding surface of the preforming mold 1, For example, a material such as metal such as nichrome or stainless steel, rubber or resin mixed with carbon, or carbon fiber can be used. These are provided on the molding surface along the cut line of the insert film 2 so as to be in contact with the preform when the preform is completed (see FIG. 2). At this time, the electric heating element 3 does not need to be linear like a nichrome wire, for example, and it is sufficient that the portion in contact with the insert film 2 is linearly exposed on the surface of the molded product (see FIG. 3). Further, as the electric heating element 3, an ink having the above-mentioned heat-generating properties may be applied and printed linearly on the molding surface of the preforming mold 1. Further, the contact surface of the electric heating element 3 with the insert film 2 may be covered with a heat conductive electric insulating material. The temperature of the electric heating element 3 is appropriately set in accordance with the material of the insert film 2 so that the cut portion of the insert film 2 is heated to a temperature higher than its melting temperature by contact with the electric heating element 3. The exposed width of the electric heating element 3 is not particularly limited. However, if the width is too small, the durability is inferior. On the contrary, if the width is too wide, the resistance generally decreases in inverse proportion to the width of the resistance. In order to generate the electric current, a large amount of current must be supplied, and the efficiency is low.

Hereinafter, the film insert molding method of the present invention using the preforming mold 1 having the above cutting means will be described.

First, the insert film 2 is positioned at an accurate position with respect to the preforming mold 1. At this time, the single-piece insert film 2 may be fed one by one, or a necessary portion of the long insert film 2 may be sent intermittently.

The insert film 2 is obtained by forming a pattern layer, an adhesive layer, and the like on a base film. Examples of the material of the base film include a base material of a normal insert film 2 such as a resin film such as a polyethylene resin, a polycarbonate resin, a polyester resin, an acrylic resin, and a polyvinyl chloride resin, or a composite of the above films. What is used as a film can be used. The picture layer is usually formed as a printing layer on the base film. As the material of the printing layer, polyvinyl resin, polyamide resin, polyester resin,
Using a resin such as an acrylic resin, a polyurethane resin, a polyvinyl acetal resin, a polyester urethane resin, a cellulose ester resin, an alkyd resin as a binder, and using a coloring ink containing a pigment or dye of an appropriate color as a coloring agent, There are translucent coloring, translucent colorless or shading coloring. The printing layer may be provided entirely or partially depending on the picture to be expressed. The picture layer may be composed of a metal thin film layer or a combination of a printing layer and a metal thin film layer. The metal thin film layer is for expressing metallic luster as a picture layer, and is formed by a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, or the like.
In this case, metals such as aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, and zinc, and alloys or compounds thereof are used according to a desired metallic gloss color. The adhesive layer is for bonding each of the above layers to the surface of the molded article. As the adhesive layer, a heat-sensitive or pressure-sensitive resin suitable for a molding resin material described later is appropriately used. For example, when the material of the molding resin is an acrylic resin, an acrylic resin may be used. When the material of the molding resin is a polyphenylene oxide / polystyrene resin, a polycarbonate resin, a styrene copolymer resin, or a polystyrene blend resin, an acrylic resin, a polystyrene resin, or a polyamide resin having an affinity for these resins. Resin or the like may be used.

When the insert film 2 is a transfer film from which the base film is peeled after molding, a release layer or a release layer may be provided on the base film. The release layer releases the mold release from the transfer layer together with the base film when the base film is peeled off. The release layer includes a melamine resin-based release agent, a silicone resin-based release agent, a fluororesin-based release agent, a cellulose derivative-based release agent, a urea resin-based release agent, a polyolefin resin-based release agent, and a paraffin-based release agent. A release agent and a composite release agent thereof can be used. The release layer is formed entirely or partially on the base film or the release layer, and when the base film is separated,
This is the layer which is peeled off from the base film or the release layer and becomes the outermost surface of the transferred material. The release layer may be a polyacrylic resin, a polyester resin, a polyvinyl chloride resin, a cellulose resin, a rubber resin, a polyurethane resin, a polyvinyl acetate resin, or a vinyl chloride-vinyl acetate copolymer resin. And a copolymer such as ethylene-vinyl acetate copolymer resin. When the release layer requires hardness, a photocurable resin such as an ultraviolet curable resin, a radiation curable resin such as an electron beam curable resin, or a thermosetting resin may be selected and used.

The structure of the insert film 2 is not limited to the above-described embodiment. For example, when a material having excellent adhesiveness to a molded product is used as the material of the picture layer, the adhesive layer is not formed. Can be omitted.

Next, the insert film 2 is preformed along the forming surface of the preforming die 1. As the preforming means, there are vacuum forming, pressure forming, press working and the like.

In the case of vacuum forming (see FIG. 1), after the insert film 2 is fixed to the preforming mold 1 by the clamp 4 or the like, the vacuum suction means such as the vacuum pump 6 attached to the preforming mold 1 is operated. Then, the preforming mold 1 is passed through the molding surface of the preforming mold 1 and the vacuum suction port provided therearound.
The air in the space between the molding surface and the insert film 2 is evacuated. As a result, the insert film 2 comes into close contact with the molding surface of the preforming mold 1, and the preforming is completed (see FIG. 4). Before or simultaneously with the start of evacuation, the insert film 2 may be heated and softened by a heating device such as a heater 5 as shown in FIG. 1 so that the insert film 2 can be easily formed.

In the case of air pressure molding (not shown), the insert film is fixed to a preforming mold by a clamp or the like, and then a pneumatic means such as a compressor attached to the preforming mold is operated to insert the insert film. Apply pressure greater than atmospheric pressure from the side opposite to the preforming mold side of
The air in the space between the molding surface of the preforming mold and the insert film is expelled. As a result, the insert film adheres along the molding surface of the preforming mold, and the preforming is completed. Before or simultaneously with the start of the compressed air, the insert film may be heated and softened so that the insert film can be easily formed. Moreover, you may use together with said vacuum forming.

In the case of press molding (not shown), a pressing means provided on the preforming die is operated to press a pressing die corresponding to a reversal die of the preforming die from the upper surface of the insert film, and press the preforming die. The air in the space between the molding surface of the molding die and the insert film is expelled. As a result, the insert film adheres along the molding surface of the preforming mold, and the preforming is completed. Before or simultaneously with the pressing, the insert film may be heated and softened so that the insert film is easily formed. In order to heat simultaneously with the pressing, the pressing mold may be heated.

Next, the insert film 2 is cut along the predetermined shape by the cutting means. That is,
By causing the electric heating element 3 to generate heat in a state where the insert film 2 is preformed on the preforming mold 1, the insert film 2 is burned off by the electric heating element 3 that contacts along a predetermined shape (see FIG. 5). .

Next, the preformed insert film 2 cut into a predetermined shape is taken out of the preforming die 1 and
The preforming and cutting steps are completed.

Thereafter, using the insert film 2 preformed and cut into a predetermined shape, painting is performed on the surface of the resin molded product as follows.

First, the cut insert film 2 is mounted by a robot or the like on a portion of the cavity forming surface of one mold of the injection mold where the insert film 2 is arranged.

Next, the injection mold is closed.

Next, molten resin is injected and filled into the cavity of the injection mold. In other words, by the pressure of the molten resin injected into the cavity from the injection port of the other mold,
The insert film 2 is pressed against the inner wall of the mold and securely adheres. The resin to be filled may be colored or uncolored. Examples of the resin material include a general-purpose resin such as a polystyrene resin, a polyolefin resin, an ABS resin, an AS resin, and an AN resin. In addition, general-purpose engineering resins such as polyphenylene oxide / polystyrene resin, polycarbonate resin, polyacetal resin, acrylic resin, polycarbonate modified polyphenylene ether resin, polybutylene terephthalate resin, polybutylene terephthalate resin, ultra-high molecular weight polyethylene resin, and polysulfone resin Super engineering resins such as polyphenylene sulfide resin, polyphenylene oxide resin, polyarylate resin, polyetherimide resin, polyimide resin, liquid crystal polyester resin, and polyallyl heat resistant resin can also be used.

Finally, the mold for injection molding is opened, and the molded product having the insert film 2 adhered to the surface is taken out. Here, when the insert film 2 is a laminate film, the painting is performed as it is, and all the layers of the insert film 2 are bonded and integrated with the surface of the molded product to form a decorative layer. On the other hand, when the insert film 2 is a transfer film, only the base film of the insert film 2 integrated on the surface of the molded product is peeled off after opening or simultaneously with opening the mold, and a transfer layer such as a picture layer is removed. Painting is completed by remaining on the molded article side to form a decorative layer.

[0031]

EXAMPLE An electric heating element made of a nichrome wire having a diameter of 0.5 mm was fixed to a heat insulating electric insulating material made of mica, and they were fixed to a preforming mold. At this time, the nichrome wire
It was set so as to be in contact at the time of completion of preforming along the cut line of the insert film. The fixing method of the nichrome wire and the mica was intermittently embedding the nichrome wire in the mica and fixing it. At this time, it was installed so that the nichrome wire was not interrupted when viewed from above.

As the base film of the insert film, polymethyl methacrylate (PMM) having a thickness of 125 μm was used.
A) A film was used. A pattern layer and an adhesive layer were formed on the base film. The picture layer was formed by a gravure printing method using an ink composed of an acrylic resin containing a coloring pigment. The adhesive layer was formed by a gravure printing method using an ink composed of a chlorinated vinyl-vinyl acetate copolymer resin.

After fixing the insert film to the above-mentioned preforming mold using a clamp, heating the insert film with an infrared heater set at 300 ° C. at a position 20 mm away from the insert film for 10 seconds, From the vacuum suction port installed in, using the attached vacuum pump,
Air was removed between the insert film and the molding surface of the preforming mold, and the insert film was brought into close contact with the molding surface of the preforming mold.

When the molding is completed and the electric heating element is in contact with the film along the cut line of the insert film, a voltage of 24 V is applied to the electric heating element for 2 seconds to generate heat and come into contact with the electric heating element. The part of the insert film was burned off.

The insert film cut into the predetermined shape was inserted between injection molds, and the cut insert film was mounted at a predetermined position on the cavity forming surface of one of the molds. After the mold is closed, acrylonitrile-butadiene-styrene copolymer resin (AB) is formed in the cavity at a molding temperature of 220 to 240 ° C and a mold temperature of 50 ° C.
Injection molding was performed using S) as a molding resin. After the resin was cooled and solidified, the mold was opened, and a molded product having an insert film adhered to the surface was taken out.

The molded product thus obtained had a high yield rate and the molding process was excellent in productivity and economic efficiency.

[0037]

The film insert molding method of the present invention and the preforming mold used therein have the above-described structure and operation, and all the following effects 1) to 3) can be obtained.

1) According to the present invention, since the electric heating element is provided in the preforming mold and the insert film is cut, even when cutting along the three-dimensional shape of the preformed insert film, the cutting is performed. The film shape at the position does not matter. And because I do not make a blade,
It doesn't require much labor and cost like punching.

2) In the present invention, since the insert film is burned off by the heat of the electric heating element, the cut surface is melted and no cutting waste is generated, and the cutting waste adheres to the cut out cut film like punching or NC cutting. Without
There is no defective product in which cutting chips adhere to the surface of the molded product.

3) In the present invention, an electric heating element that comes into contact with the preform is completed along the cut line of the insert film in the preforming mold, and the portion of the insert film that comes into contact with the electric heating element is burned off. Unlike the NC cut and the laser cut, the total length to be cut does not matter, and it does not take much time. In addition, a computer for numerically controlling the position such as NC cut or laser cut,
Equipment such as a cutter and a robot for precisely moving the laser irradiation unit is not required, and cost is not required.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a preforming and cutting means for an insert film according to the present invention.

FIG. 2 is a view showing one embodiment of a preforming mold provided with an electric heating element according to the present invention.

FIG. 3 is a view showing one embodiment of an installation state of an electric heating element according to the present invention in a preforming mold.

FIG. 4 is a cross-sectional view showing one embodiment of a means for preforming and cutting an insert film according to the present invention.

FIG. 5 is a cross-sectional view showing one embodiment of a means for preforming and cutting an insert film according to the present invention.

FIG. 6 is a view showing an example of cutting of a preformed insert film.

FIG. 7 is a view showing an example of a punching blade used for cutting means of a preformed insert film in a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pre-molding die 2 Insert film 3 Electric heating element 4 Clamp 5 Heater 6 Vacuum pump 7 Electric insulating material 8 Punching blade

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshikazu Kobe 3 Nibu Hanaicho, Nakagyo-ku, Kyoto-shi, Kyoto Inside Nihon Photo Printing Co., Ltd. Address Nihon Photo Printing Co., Ltd. F term (reference) 4F202 AA13 AA21 AA28 AA29 AH23 AH26 AH42 AH48 AH51 AK05 AK09 CA17 CB01 CN01 CN18 CN21 4F206 AA13 AA21 AA28 AA29 AH23 AH26 AH42 AH48 JH09 J05J05 J05JF12 AA13 AA21 AA28 AA29 AH23 AH26 AH42 AH48 AH51 AK05 AK09 MA01 MB01 MC02 MH07 MH19 MJ22 MW01 MW23

Claims (2)

[Claims] 1. A film insert in which a preformed insert film cut into a predetermined shape is conveyed and fixed in an injection mold, and then closed to fill a molten resin into a cavity of the injection mold. In the molding method, an electric heating element to be contacted at the time of completion of preforming along the cut line of the insert film is provided in the preforming mold,
A film insert molding method, characterized in that a portion of the insert film that is in contact with the electric heating element is burned off by applying a current to the electric heating element in a state where the insert film is preformed on the preforming mold. 2. A preforming mold for use in the film insert molding method according to claim 1, wherein an electric heating element which comes into contact with the cut line of the insert film when preforming is completed is provided in the preforming mold. A preforming mold.