JPH03286835A - Method of decorating molded object - Google Patents

Abstract

PURPOSE:To prevent the air from being entrapped between a core and a skin by a method in which the space between a receiving holder and the skin is closed in the state where the skin is not brought in contact with the core, and said closed space therebetween is kept in vacuum condition. CONSTITUTION:In the state where the top force 33 which vacuum-molds sheet material 42 is held in the vacuum condition as it is, the bottom force 22b on which the surface of the bace plate 23 is coated with an adhesive layer is raised by the cylinder 21 for raising and lowering, and the raising process is stopped immediately before the rear surface of the sheet material 42 is brought in contact with the base plate 23. Then, a closed space (air tight chamber) is formed around the bottom force 22b by an elastic seal member 44, a box 22a, a keeping holder 41 and a seal member 42. While the vacuum condition of a top force 33 is kept, inner space 24 is allowed to communicate with vacuum source, whereby the air tight chamber of the bottom force is also kept in vacuum condition. The bottom force 22b is further raised, whereby the rear surface of the sheet material 42 is caused to adhere to the upper surface of the base plate 23. Further, the vacuum condition of the top force 33 is switched to pressurized state by a switching valve 36, and while the adhesion of the sheet 42 to the base plate 23 is heightened by air pressure, the mold release from the top force 33 is contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for decorating a molded article, in which a skin material is attached to the surface of a core material via an adhesive layer.

(Prior art) Conventionally, when attaching a skin material (hereinafter referred to as sheet material) to the surface of a core material (hereinafter referred to as substrate) via an adhesive layer, a downward molding mold (hereinafter referred to as upper mold) is used. The sheet material is formed using a holder (hereinafter referred to as the "lower mold") that faces the upper mold.
is raised, and the substrate on this lower die is pressed onto the back surface of the sheet material.

(Problem to be Solved by the Invention) This conventional method does not allow air trapped between the sheet material and the substrate to escape when the sheet material is brought into close contact with the surface of the substrate, especially when the substrate is a solid type. , there is a problem that bulges occur on the surface of the molded product. In order to eliminate this bulge, there is a method to remove the entrained air by providing a large number of ventilation holes in the solid board, but unless the interval between each ventilation hole is set very small, the expansion will occur between the ventilation holes. The problem occurs.

The present invention has been made in view of these points, and it is possible to prevent the risk of air being trapped between the core material and the skin material even if it is a solid type core material, and to form a surface material that is well coated on the surface of the core material. The purpose of this invention is to provide a method for decorating molded products that can be closely attached to molded products.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a method for attaching a skin material 42 to a surface of a core material 23 via an adhesive layer.
In the method for decorating a molded product, a core material 23 is set on a pedestal 22, and a heated and softened skin is placed between the core material 23 and a molding die 33 placed opposite to the pedestal 22. Material 4
2, a step of adsorbing the skin material 42 to the molding mold 33 by bringing the skin material 42 and the molding mold 33 into contact and applying vacuum suction, and a step of adsorbing the skin material 42 and the core material 23 to the molding mold 33. It consists of a step of sealing the space between the pedestal 22 and the skin material 42 in a state where they are not in contact with each other and creating a vacuum state in the sealed space between them, and a step of releasing the adsorption of the skin material 42 to the mold 33. It is a decoration method.

(Function) In the present invention, a skin material 42 is arranged between the mold 33 and the core material 23 of the pedestal 22, and the skin material 42 is heated and softened.
After creating a shape by sucking it into the mold 33, the core material 23 and the skin material 42 are brought close to touching each other, and the air in the sealed space provided between the skin material 42 and the holder 22 is removed. By eliminating air between the core material 23 and the skin material 42 and bringing the core material 23 and the skin material 42 into close contact, the core material 2
3 and the skin material 42 is eliminated.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples shown in the drawings.

As shown in FIG. 1, an upper machine frame 13 is integrally provided with a lower machine frame 11 via a support 12. As shown in FIG.

A box 22 that constitutes the lower side of a cradle 22 is attached to the lower machine frame 11 via a vertical movement cylinder 21! is provided, and this box 22! A lower mold 22b constituting the upper side of the pedestal 22 is provided on the upper surface using a porous material, and a solid substrate 23 as a core material is placed on the upper surface of the lower mold 22b. This substrate 23 may be either a metal plate or a resin plate, and is used, for example, as a pillar garnish for automobile interior parts. box 22
The inner cavity 24 of 2 is communicated with a vacuum source via a valve 26 in a conduit 25.

Further, a ventilation hole 27 is provided in the upper surface of the box 22M to allow ventilation to the outside through the inner hole of the porous material of the lower die 22b.

A mold 32 is provided on the upper machine frame 13 via a vertically moving cylinder 31, and an upper mold 33 as a molding mold is provided in the lower part of the mold 32 using a porous material. An inner space 34 is formed in the upper part of the formwork 32, and this inner space 34 is selectively communicated with a vacuum source and an air pressure source via a conduit 35, a switching valve 36, and the like. Further, a vent hole 37 is provided below the inner cavity 34 to allow ventilation to the outside through the inner hole of the porous material of the upper die 33.

Further, between the lower mold 22b and the upper mold 33, a holding table 4 is provided.
1 is arranged, and a sheet material 42 with a foam layer as a skin material is held on the upper surface of this holding table 41.

This sheet material 42 is made of PVC or foamed PVC.

Non-breathable resin such as PP, foamed PP, PE, ABS, etc., or a foamed layer 43 laminated on the back side of these sheet materials 42 is used. This foam layer 43 may be omitted. Further, an elastic sealing material 44 is integrally fitted to the lower surface of the holding base 41.

Next, a molding method using the apparatus shown in FIG. 1 will be explained with reference to FIGS. 2 to 4.

As shown in FIG. 2, the heated and softened sheet material 4
In contrast to 2, the upper mold 33 is lowered by the vertical movement cylinder 31 and fixed with the sheet material 42 sandwiched between it and the holding table 41, and then the inner space 34 is communicated with a vacuum source to evacuate the upper mold 33. , the sheet material 42 is sucked up and molded into the shape of the upper die 33.

Then, as shown in FIG. 3, while keeping the upper mold 33 in which the sheet material 42 has been vacuum-formed in the same vacuum state, the lower mold 22b on which the substrate 23 with the adhesive layer coated on the surface is placed is placed.
is raised by the vertical movement cylinder 21, and the sheet material 42
The rise is stopped immediately before the back surface of the substrate 23 comes into contact with the substrate 23. At this time, the upper surface of the box 22a that constitutes the pedestal 22 together with the lower die 22b compresses the elastic sealing material 44 provided on the lower surface of the sheet material holding pedestal 41, and this elastic sealing material 4
4, the box 22a, the holding table 41, and the sheet material 42 form a sealed space (airtight chamber) around the lower mold 22b. The airtight chamber of this lower mold part is also brought into a vacuum state by communicating with a vacuum source. Then, the lower mold 22b is further raised in this vacuum, and the back surface of the sheet material 42 and the upper surface of the substrate 23 are brought into close contact with each other and bonded by the intervening adhesive layer. in this case,
The sheet material 42 and the substrate 23 can be brought into close contact with each other without air being a cause of "bulge".

Furthermore, as shown in FIG. 4, the vacuum state of the upper mold 33 is switched to a pressurized state by the switching valve 36, and the air pressure increases the adhesion of the sheet material 42 to the substrate 23, and also separates it from the upper mold 33. Plan the pattern. Due to this pressure switching and the shape of the lower die 22b that is slightly smaller than the substrate 23, the f-type 22b
It is possible to easily wind the sheet material 42 onto the back side of the more protruding peripheral edge of the substrate 23. Further, instead of actively pressurizing as described above, it is sufficient to simply return to the atmospheric pressure state.

It goes without saying that the above embodiments show only examples of the present invention, and that the present invention is not limited to these embodiments. Modifications different from the illustrated embodiment will be described below.

In the illustrated embodiment, the upper mold 33 and the lower mold 22b are moved up and down, but the upper mold 33 is fixed at a fixed position and the holding base 4
1 can be moved up and down, and the sheet material 42 can be sandwiched between the holding stand 41 and the upper mold 33. Alternatively, the lower mold 22b can be fixed and the upper mold 33 and the holding stand 41 can be moved up and down. By providing it movably, the same effect can be obtained by lowering the holding table 41 together with the upper mold 33 toward the lower mold after the upper mold 33 has been lowered to form a sheet.

In addition, a heating means is embedded in the upper mold 33 and the sheet material 42 is
It may also be possible to prevent the cooling of the

Furthermore, the lower mold 22b and the upper mold 33 may be made of not only a porous material but also a solid material provided with a large number of ventilation holes.

The lower mold box 22a may also be configured to be able to selectively communicate with a vacuum source and an air pressure source via a switching valve. In that case, the lower mold 22b is raised as shown in FIG.
Before making the airtight chamber around the lower mold 22b into a vacuum state,
- By temporarily communicating the inner space 24 with an air pressure source to pressurize the space around the lower mold 22b and pressing the sheet material 42 against the upper mold 33, the grains etc. provided on the upper mold 33 can be removed. may be copied onto the sheet material 42.

Finally, the sheet material 42 may not only be held on the holding base 41 at a position facing the upper die 33, but may also be held by a sheet holding mechanism independent from the upper die 33.

〔Effect of the invention〕

As described above, according to the present invention, the space between the pedestal and the skin material is sealed without the skin material and the core material being in contact with each other, and the sealed space therebetween is made into a vacuum state. , even when covering a solid type core material with a skin material,
Air entrainment between the core material and the skin material can be prevented without providing ventilation holes in the core material. Furthermore, even if the surface of the core material is uneven, since the core material and the skin material are brought into close contact with each other in a vacuum state, the skin material can be brought into close contact with the surface shape of the core material. Further, the skin material can be easily wrapped around the back side of the edge of the core material.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an apparatus used in the molded product decorating method of the present invention, and FIGS. 2, 3, and 4 are cross-sectional views showing the steps of the method. 22... cradle, 23... substrate as a core material, 33. upper die as a mold for molding, 412... sheet material as a skin material. ”-mouth”

Claims (1)

[Claims] (1) In a method for decorating molded products in which a skin material is attached to the surface of a core material via an adhesive layer, the core material is set on a pedestal, and a mold and core are placed opposite the pedestal. a step of stretching a heat-softened skin material between the skin material and the mold, a step of adsorbing the skin material to the mold by bringing the skin material into contact with the mold and applying vacuum suction; The process consists of a process of sealing the space between the pedestal and the skin material without contacting the core material, and creating a vacuum state in the sealed space between them, and a process of releasing the adsorption of the skin material to the mold. A method for decorating a molded product characterized by: