JPH05329884A - Production of decorative molded object - Google Patents

Abstract

PURPOSE:To provide a decorative layer having no wrinkle on a thick corner part of a molded object and to prevent an occurrence of a sink mark. CONSTITUTION:A decorative sheet 2 provided with a decorative layer on a substrate sheet is fixed to a mold A 11 having a cavity 13. A mold B 12 is provided with a projected part 3 having round corner parts 31 and an injection port 14. The decorative sheet 2 is pressed into the cavity 13 of the mold A 11 by the projected part 3. In a mold touch state, a melt resin is injected into the cavity 13 to be fully charged therein. After that, the mold is completely closed. The obtained molded object having thick corner parts formed by the corner parts 31 of the projected part 3 of the mold B 12 is cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative molded product, which is capable of forming a wrinkle-free decorative layer by preventing warping and sink marks at the corners of a thick molded product.

[0002]

2. Description of the Related Art As a conventional method for producing a decorative molded article,
The decorative sheet having the decorative layer formed on the base sheet is fixed to the mold A having the cavity, and the decorative sheet is pushed into the cavity of the mold A by the convex portion of the mold B having the injection port. There is a method of closing and forming a decorative sheet on the surface of the molded product simultaneously with injection molding.

As another manufacturing method, a decorative sheet which has been heated and easily deformed is vacuum-sucked into close contact with the inner surface of the cavity of the mold A, and at the same time when the molten resin is injected, the decorative sheet is formed on the surface of the molded product. There is a method of forming.

[0004]

However, in the former method, when the convex portion of the mold B has a large rise and the distance for pushing the decorative sheet into the cavity is long, the mold B is pushed when pushing the decorative sheet into the cavity. The corners of the convex portions of are strongly pressed against the decorative sheet. Therefore, the decorative sheet is damaged or wrinkled, and a beautiful decorative molded product cannot be obtained.

In the latter method, the number of manufacturing steps such as the step of heating the decorative sheet and the step of vacuum suction is large, resulting in poor production efficiency.

In both methods, a molded product having a thick wall portion suffers sink marks, distortion, and warp due to the volumetric shrinkage of the resin, so that the surface of the molded product is dented or the formation position of the decoration is displaced, resulting in a clean appearance. No decorative molded product can be obtained.

[0007]

The present invention is configured as follows in order to solve the above problems. That is, a decorative sheet in which a decorative layer is formed on the base sheet,
The cavity is fixed to the mold A having a cavity, the decorative sheet is pushed into the cavity of the mold A by the convex portion of the mold B having the injection port, the molten resin is injected from the injection port, and the cavity of the mold A is caused by the resin pressure. In a method for producing a decorative molded product, which comprises forming a decorative sheet on the surface at the same time as forming a molded product by closely adhering a decorative sheet to the surface, the decorative sheet is a mold B in which a corner of a convex portion does not show an acute angle. Is pressed into the cavity of the mold A to make the mold touch, the molten resin is injected into the cavity to fill it, and then the mold is closed, and the thick wall formed by the corners of the protrusions of the mold B is formed. The molded product having the corner portion was configured to be cooled.

According to the present invention, a decorative sheet is obtained by forming a transfer layer composed of a release layer, a decorative layer and an adhesive layer on a base sheet, and the transfer layer alone is formed on the surface of a molded article. The sheet may be peeled off.

[0009]

Embodiments will be described below in detail with reference to the drawings. 1 to 4 are cross-sectional views of one step of the method for manufacturing a decorative molded product of the present invention. 5 and 6 are cross-sectional views of an example of a mold used in the manufacturing method of the present invention. Figure 7
FIG. 3 is a cross-sectional view of a decorative molded product obtained by the manufacturing method of the present invention. FIG. 8 is a perspective view of a decorative molded product obtained by the manufacturing method of the present invention.

The present invention will be described in the order of steps. First, the following decorative molding device is prepared. The decorative molding device includes a mold A11 having a cavity 13, a mold B12 having an injection port 14, a clamp device 21 for fixing the decorative sheet 2 to the surface of the mold A11, and a mold closing mold opening process. The mold driving device 5 for performing the above, and the injection device 6 for injecting the molten resin 61 into the cavity portion 7.

The mold B12 is a cavity 1 of the mold A11.
3 has a convex portion 3 into which the decorative sheet 2 is pushed, and a corner portion 31 of the convex portion 3 has a shape that does not exhibit an acute angle. The shape that does not exhibit an acute angle means that the convex portion 3 forms the decorative sheet 2 in the cavity 13
The decorative sheet 2 does not have scratches or wrinkles when pushed in, for example, the corners 31 of the protrusions 3 are rounded (see FIGS. 5 and 6), and the cross section does not exhibit an acute angle. There are polygonal shapes (see FIG. 1) and the like.

The decorative sheet 2 is a sheet for decorating the surface of the molded product 4, and a transfer layer comprising a release layer, a decorative layer, an adhesive layer, etc. is formed on a long base sheet. It is a thing. The base sheet is a film-shaped material such as polyethylene terephthalate, polypropylene, or polybutylene terephthalate. The release layer is a resin layer that imparts releasability between the base sheet and the decorative layer. The decorative layer is a layer that imparts decorativeness and functionality to the surface of the molded product. The decorative layer has a pattern, a pattern made of printing ink such as characters and symbols, and a conductive pattern formed of a conductive material. You may have a metal vapor deposition layer if needed. The adhesive layer is a resin layer that adheres the decorative layer and the molded product 4 together. This decorative sheet 2 is a molded product 4
After adhering to the surface, the base sheet is peeled off, and only the transfer layer is transferred to the surface of the molded product 4.

The decorative sheet 2 may include a base sheet on which a decorative layer and an adhesive layer are formed. In this case, the base sheet is also provided on the surface of the molded product 4 together with the decorative layer and the adhesive layer (see FIGS. 7 and 8).

The decorative sheet 2 having the decorative layer transferred to the molded product 4 is transferred to the mold A11 by using the above-described decorative molding device.
After being positioned at a predetermined position with respect to the cavity 13 of FIG. 1, the decorative sheet 2 is sandwiched and fixed to the parting surface of the mold A11 by the clamp device 21 or the like (see FIG. 1).

The decorative sheet 2 may be wound around a roll and fed at a predetermined pitch between molds to form a transfer layer on the molded product, and may be wound around another roll again. Alternatively, the necessary parts may be separated from the beginning and placed one by one.

Next, the decorative sheet 2 is pushed into the cavity 13 of the mold A11 by the convex portion 3 of the mold B12 having the injection port 14 so that the mold is touched.

When the decoration sheet 2 is pushed in, the driving rod 51 of the mold driving device 5 is operated to move the convex portion 3 of the mold B12.
1 is made to plunge into the cavity 13 of the mold A11.
The corner portion 31 of the convex portion 3 of the mold B12 is pressed against the decorative sheet 2, but scratches and wrinkles do not occur.

The mold touch state is a state in which the mold closing is not completed completely. By setting the mold touch state, the cavity portion 7 is formed by the surface of the cavity 13 of the mold A11 and the surface of the mold B12 protruding into the cavity 13. The cavity portion 7 has a volume larger than the volume of the desired shape of the molded product, and is a closed space that does not flow out even if the molten resin is filled.

Next, with the mold being touched, the molten resin 61 is injected from the injection port 14 of the mold B12 to fill the cavity 7 and the injection is completed. Molten resin 61
In response to the injection pressure of the
It is pressed against and closely adheres to the surface of the cavity 13 of 11 (see FIG. 3).

Next, the mold closing is completed, and the cavity portion 7 has a desired volume of the shape of the molded product. The molten resin in the cavity 7 in the state of touching the mold is compressed into a desired shape of the molded product. If necessary, before completing the mold closing, mold B1
The two injection ports 14 may be sealed. The portion of the cavity portion 7 that is molded by the corner portion 31 of the convex portion 3 of the mold A11 corresponds to the thick corner portion 41 of the molded product (see FIGS. 7 and 8).

As the molten resin 61, ABS resin, polycarbonate resin, polyacrylic resin, polystyrene resin, polyether sulfone, polyetherimide, polyether ether ketone, polysulfone, polyacrylate, polybutylene terephthalate, polyethylene terephthalate, etc. is there.

Next, the decorated molded product 4 is cooled, the mold is opened, and the decorated molded product 4 having thick-walled molded product corners 41 is formed.
Is removed from the mold (see FIG. 8).

According to the present invention, the cavity formed in the state of touching the mold is filled with the molten resin, and then the mold is further closed. Therefore, the injection pressure of the molten resin can be small. Therefore, there is little friction between the decorative sheet and the molten resin, and the decorative sheet 2 is not wrinkled or damaged. Further, the formation position of the decoration does not shift.

Further, according to the present invention, the molten resin can be uniformly pressed without uneven filling. Therefore, the volumetric shrinkage of the molded product due to cooling after molding is suppressed, and the decorative molded product corner portion 4
No sink marks occur in the thick part of 1.

Further, according to the present invention, the temperature of the molten resin can be controlled sufficiently. Therefore, even when molding a large decorative molded product, the cooling time is short.

[0026]

According to the method for producing a decorative molded product of the present invention, the decorative sheet is pushed into the cavity by the mold B in which the corners of the protrusions do not exhibit an acute angle, and the mold is touched. The molten resin is injected and filled, the decorative sheet is brought into close contact with the mold, and the mold is closed to obtain a thick molded product formed by the corners of the convex portion of the mold B. Is configured.

Therefore, a transfer layer or a decorative sheet without wrinkles or damage can be provided on the corners of the molded product, and a beautiful decorated molded product can be obtained in which the thick corners of the molded product are not sinked.

Further, since there is no need for a step or a device for bringing the decorative sheet into close contact with the inner surface of the cavity, the production efficiency is good and the cost is low.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of one step of a method for manufacturing a decorative molded product and a decorative molding device according to the present invention.

FIG. 2 is a cross-sectional view of one step of the method for manufacturing a decorative molded product and the decorative molding device of the present invention.

FIG. 3 is a cross-sectional view of one step of the method for manufacturing a decorative molded product and the decorative molding device of the present invention.

FIG. 4 is a cross-sectional view of one step of the method for manufacturing a decorative molded product and the decorative molding device of the present invention.

FIG. 5 is a cross-sectional view of a mold of the manufacturing method of the present invention.

FIG. 6 is a cross-sectional view of a mold of the manufacturing method of the present invention.

FIG. 7 is a cross-sectional view of a decorative molded product obtained by the manufacturing method of the present invention.

FIG. 8 is a perspective view of a decorative molded product obtained by the manufacturing method of the present invention.

[Explanation of Codes] 11 Mold A 12 Mold B 13 Cavity 14 Injection Port 2 Decorative Sheet 21 Clamping Device 3 Convex Part 31 Corner 4 Molded Product 41 Molded Product Corner 5 Mold Drive Device 51 Drive Rod 6 Injection Device 61 Molten resin 7 Cavity

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display area B29K 105: 24 B29L 9:00 4F

Claims (2)

[Claims] 1. A decorative sheet in which a decorative layer is formed on a base sheet is fixed to a mold A having a cavity, and the decorative sheet is fixed to the mold A by a convex portion of a mold B having an injection port. Of a decorated molded product in which a decorative sheet is pushed into a cavity, a molten resin is injected from an injection port, and a decorative sheet is brought into close contact with the cavity surface of a mold A by a resin pressure to form a molded sheet at the same time as molding of the molded product. In the manufacturing method, after the decorative sheet is pushed into the cavity of the mold A by the mold B in which the corners of the convex portions do not show an acute angle, the mold is touched, and the molten resin is injected into the cavity to fill the mold. A method for producing a decorative molded article, characterized by completing the closing and cooling the molded article having a thick corner portion formed by the corner portion of the convex portion of the mold B. 2. A decorative sheet comprising a base sheet and a transfer layer comprising a release layer, a decorative layer and an adhesive layer formed on the base sheet, wherein the transfer layer alone is formed on the surface of the molded article to form a base sheet. The method for producing a decorated molded product according to claim 1, wherein the decorated molded product is peeled off.