JPH02233219A - Molding method for powder molten skin material - Google Patents

Abstract

PURPOSE:To emphasize the contrast of luster by applying a coating material to the surface of a skin material wherein the contrast of luster has been deteriorated by molding due to a molding mold having small unevennesses formed on the surface by sand blasting, etc. CONSTITUTION:The surface of a molding mold 3 is formed of both the large uneven parts 4b... having the small unevennesses 6a... and the smooth parts 5b by sand blasting treatment. Therefore on the surface of a skin material 1 molded by this molding mold 3, the small unevennesses 6 are generated to the large uneven parts 4a... and the smooth parts 5a respectively. When coating material 2 is applied to the surface of this skin material 1, the small unevennesses 6 are buried and both the large uneven parts 4... and the smooth parts 5... are formed. Especially the small unevennesses 6 in the smooth parts 5a are buried and made nearly smooth. Therefore luster is deteriorated in the large uneven parts 4 and also expression having lustre can be shown in the smooth parts 5 and thereby the contrast of luster is strengthened. Further as the skin material, thermoplastic resin such as polyvinyl chloride system is ordinarily utilized. Further as the coating material, urethane-based resin which is good in the contrast of luster and hand-feeling is suitable and viscosity is preferably regulated to 500cps or below.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to an improvement in a molding method for interior materials for automobiles, such as instrument pads and door trims.

[Conventional technology]

Currently, as automotive interior materials move toward higher quality, there is an increasing demand for surface grain patterns (embossed) from traditional single-pattern etched grains to delicate patterns that can express natural leather grains with a realistic feel. .

This is because the grain of natural leather is delicate, and the peaks and valleys of the grain have a glossy contrast, giving it a visually three-dimensional effect.

Currently, one of the methods that is effective in transferring delicate grains to molded products is the powder melt molding method.

To explain an example of this based on a drawing, 3 in Figure 4 is an electroformed skin made by attaching natural leather to a master model. It is a cross-sectional view of the main parts of the material mold at the initial stage of production, and the surface has large uneven parts 4d... and smooth parts 5d.
... is formed.

Note that the mold 3 is generally a Nisokel electroforming mold made by the silver bell method.

1 in FIG. 5 is a skin material that is powder-melted and molded using, for example, PVC powder, using the mold 3 shown in FIG.
・A surface with a strong contrast of luster is obtained, which is composed of the matte large uneven areas 4C and the glossy smooth areas 5C transferred from the surface.

[Problem to be solved by the invention]

In the case of the above molding method using powder melting, there are the following problems.

That is, during molding, thermal decomposition products such as PVC powder, plasticizer, metal stabilizer, etc., which are powder-molten molding materials, are melted into the mold 3.
In order to adhere to the surface of the mold, it is usually necessary to remove the adhered substances adhering to the surface of the mold by dry and wet sand blasting.

However, since the mold 3 usually uses a two-layer electroforming mold, its surface hardness (visocurse hardness) is about 250, which is soft. Therefore, after several times of sandblasting, the fourth
The large uneven portion 4d of the mold 3 in the figure and the smooth portion 5
As shown in FIG. 3, d... is a large uneven portion 4b having small unevenness 6a caused by the sandblasting process and a smooth portion 5b. Therefore, as shown in FIG. 2, on the surface of the skin material 1 molded by this mold 3, small irregularities 6 are generated in the large uneven parts 4a... and in the smooth parts 5a, but especially in the smooth parts 5a. Due to the small irregularities 6 generated on the surface, the luster of this part is lost, and the contrast of the luster expressed on the surface is significantly lower than that of the skin material 1 molded using the mold shown in Figure 5 at the initial stage of production. Therefore, it becomes impossible to obtain a skin material 1 with a strong gloss contrast.

In order to eliminate this drawback, a new mold must be used, which ultimately shortens the life of the mold and is extremely uneconomical.

The present invention has been made in view of the above problems, and
The purpose of the present invention is to provide a method for molding a powder-fused skin material that does not easily reduce gloss contrast.

[Means to solve the problem]

In order to achieve the above object, the method for molding the powder fused skin material of the present invention is to create a powder fused skin material that expresses glossy contrast by the large embossed uneven areas and smooth areas on the surface of the skin material by transfer from the mold. In the molding method for skin materials, the gloss contrast is strengthened by applying a coating material to the surface of the skin material whose gloss contrast has decreased due to molding from a mold that has small irregularities on the surface due to sandblasting etc. .

As the skin material in the present invention, thermoplastic resin such as PVC is usually used, and as the coating material, urethane resin is suitable because it has good gloss contrast and texture, and the viscosity is It is preferably 500 cps (centivoids) or less, particularly about 50 to 100 cps.

In addition, the depth of the roughness of the dull and large uneven portion in the state of the skin material is preferably 5 microns or more, preferably 10 microns or more.

[For production]

As a result of molding using a mold with small irregularities on the surface using Sandplus 1, etc., the small irregularities formed in particularly smooth areas of the skin material are filled with the coating material applied to the surface and become almost smooth. As the gloss is reproduced, the contrast of the gloss is enhanced, similar to the surface of the skin material formed by the initial mold.

〔Example〕

The present invention will be explained below based on the drawings. 3 in Fig. 3 is:
Areas with large irregularities are glossy (areas with few irregularities and almost smooth are glossy) This is a cross-sectional view of a mold that was manufactured by attaching natural leather to the master model, and then the surface was changed by sandblasting cleaning. That is, 4b..., 5b... are each made of small irregularities 6a... by sandblasting cleaning.
These are large uneven areas and smooth areas.

The mesh size of the cleaning sandblast is 44 microns. FIG. 2 is a cross-sectional view of the skin material 1 made of PVC thermoplastic resin that has been powder-melted and molded using the mold 3 shown in FIG. 3, and shows the surface transferred from the mold shown in FIG.
It has large uneven portions 4a with a depth of 20 to 30 microns having small unevenness 6 due to sandblasting cleaning, and smooth portions 5a.

FIG. 1 is a cross-sectional view of the skin material 1 shown in FIG. 2, whose surface is coated;
5 to 2 0cps (centiboise) urethane resin
The coating material 2 is formed by spray coating to a thickness of 0 microns, and the coating material 2 fills in the small irregularities 6 in FIG. 2, forming large irregularities 4 and smooth parts 5. In particular, the small unevenness 6 in the smooth part 5a in FIG. 2 is filled with the coating material 2 and becomes almost smooth, so the large uneven part 4 is almost as dull as in FIG. 5, and the smooth part 5 is It is possible to create a glossy expression similar to Figure 5 and Baba, and the contrast of the gloss is strengthened.

〔Effect of the invention〕

According to the present invention, it has been possible to extend the life of a mold that can form a skin material with contrasting gloss.

In other words, it has become possible to extend the conventional mold life of 2,000 to 10,000 shots several times.

Furthermore, by applying a coating material to the surface, we were able to improve not only the visual contrast of gloss but also the moist feel to the touch, bringing it closer to the real thing.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a skin material whose surface has been coated as an embodiment of the present invention, Figure 2 is a cross-sectional view of the skin material before coating, and Figure 3 is a mold for the skin material shown in Figure 2. FIG. 4 is a cross-sectional view of the main part of the mold during manufacture, and FIG. 5 is a cross-sectional view of the skin material molded by the mold of FIG. 4. Explanation of symbols 1--Skin material 2-Coating material 3-Molding mold

Claims (1)

[Scope of Claims] 1. In a method for molding a powder-fused skin material that expresses glossy contrast between large embossed uneven areas and smooth areas on the surface of the skin material by transfer from a mold, the surface is coated by sandblasting, etc. A method for forming a powder-fused skin material, which is characterized by applying a coating material to the surface of the skin material whose gloss contrast has been reduced due to molding from a mold with small irregularities, thereby enhancing the gloss contrast. 2. The method for molding a powder-fused skin material according to claim 1, wherein the viscosity of the coating material is 500 cps or less. 3. The method for molding a powder-fused skin material according to claim 1 or 2, wherein the material of the coating material is a urethane resin.