JPS61233522A - Preparation of molded product with skin - Google Patents

Abstract

PURPOSE:To enhance working efficiency by dispensing with a core body and skin material bonding treatment process, by applying heat treatment to a core sheet made of a thermoplastic resin and a skin sheet and arranging both sheets on a mold in a laminated state and contacting the laminated body with the mold side under pressure to perform molding. CONSTITUTION:A core sheet 1 is heated to raise the surface temp. thereof to 140-170 deg.C and a composite skin sheet 2 and the core sheet 1 are successively laminated from the end parts of both sheets. The composite laminated body 6 is again heated to hold the surface temp. thereof to 140-170 deg.C to promote thermal plasticizing and placed on a heated mold 7 in a softened state. A large number of suction holes 9 communicated with a manifold part 8 are provided to the mold 7 by drilling and, when the air in the manifold 8 is sucked to evacu ate the same, the laminated body 6 held to a softened state is sucked to be chemically contacted and integrated with the inner surface of the mold 7 under pressure while easily deformed. After vacuum molding, the mold 7 is cooled to 50-60 deg.C and a molded product is demolded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a molded article with a skin. Examples of molded products with skins include automobile interior parts such as instrument panel butts, door trims, console boxes, etc. The skins are made of a solid single layer such as vinyl chloride or ABS resin, and a foam layer is integrated inside the solid layer. Laminated composite skins have developed, and laminates made of rigid polyurethane foam, etc., have been used as a lightweight and highly rigid core material as a backing layer to reinforce and retain the shape of this composite skin. Indeed, automobile interior parts using such a composite skin provide a soft and luxurious feel to passengers.

The present invention relates to a method for producing a molded product with a skin covering the surface of a core material with a skin.

(Prior art) As a manufacturing method for a molded product with a skin, when joining a composite skin consisting of a solid layer and a foam layer to a core, an adhesive layer is provided on the surface of the core, and the composite skin and core are bonded together. For example, a method of vacuum forming a composite skin and a core into a desired shape and then press-molding the composite skin and core is disclosed in, for example, Japanese Patent Application Laid-Open No. 52-134670.
It is disclosed in the publication No. Further, a manufacturing device in which a pre-formed core body is set in a vacuum molding mold, and then a composite skin is brought into pressure contact with the core body and bonded with an adhesive is disclosed in, for example, Japanese Patent Laid-Open No. 152066/1983. ing.

(Problems to be Solved by the Invention) As mentioned above, the conventional method for producing a molded product with a skin includes shading the skin and the core and applying an adhesive to at least one of the skin and the core. Since pre-treatment steps are required, the number of steps and work time required for these treatment steps poses a problem of inefficiency that cannot be ignored from the perspective of improving work efficiency.

(Means for Solving the Problems) The method for producing a molded article with a skin according to the present invention includes heating a thermoplastic resin core sheet and a skin sheet until the core sheet approaches a melted state. Then, both seals are arranged in a layered manner on a mold under the heat retention conditions described above, and the laminate is pressure-molded on the mold side using air pressure to deform and mold the laminate and form the gap between the sheets. With the aim of achieving bonding and bonding at the same time and improving work efficiency, we sought to simplify the work by actively utilizing the thermoplasticity of the core material and the heat-melting properties of the composite sheets that make up the laminate. It is something that

(Example) Next, a specific method for manufacturing a molded article with a skin according to the present invention will be explained using reference drawings.

FIGS. 1 to 4 are cross-sectional views showing the stepwise molding process when the present invention is carried out, and FIG. 5 is a cross-sectional view of a molded product obtained according to the present invention.

First, as a first embodiment, a molded article will be described in which the surface of a core is integrally coated with a composite skin consisting of a solid layer and a foam layer as a skin.

The core [1] used in the present invention is a thermoplastic resin sheet having a thickness of 1 to 8 mm, such as polypropylene.

It is composed of a sheet made of polyethylene, nylon, etc., and the most preferred material among these is a sheet made of polypropylene. On the other hand, the composite skin sheet (2) is made of a solid layer forming sheet (3) with a thickness of 0.3 to 1.5 fl made of polyvinyl chloride or ABS resin, and a polypropylene foam, polyethylene foam, especially cross-linked polyethylene foam. , a sheet for forming a foam layer (4) having a thickness of 2 to 4 mm and having an expansion ratio of 20 to 50 times that of a soft polyurethane and ethylene-vinyl acetate copolymer foam.

The method of forming this composite skin (2) varies depending on the material of the sheet (3) for forming a solid layer and the sheet for forming a foam layer (4). In the case of lamination of (3) and a foam layer (4) made of polypropylene foam, a composite skin sheet (2) is obtained by pressure contact with a roll via an adhesive layer.

First, as a first step, a core sheet (1) cut to a certain size is heated to a surface temperature of 140 to 170°C.

The second step is to combine the composite skin sheet (2) and the core sheet (1).
) are stacked one on top of the other in order from the ends of both sheets so as not to create an air pocket between them (see Figure 1). The composite laminate (6) consisting of the core sheet [11] and the composite skin sheet (2) obtained in this state was heated again to bring the surface temperature of the core sheet Nil side to 140 to 170°C. The temperature is maintained to promote thermoplasticization of the composite laminate (6).

The next third step is to create a core sheet (1) and a composite skin sheet.
140' to 170 described above in order to achieve good bonding and integration of f21 and to soften the solid layer (3) of the composite skin sheet (2) in the next step to facilitate its deformation.
Maintain the heating operation at ℃, thereby the core body sea) (1
1 is thermoplasticized to form a foam layer (4) of a composite skin sheet (2)
The material is thermally fused to activate the bonding of each component. Note that if the materials of the folding members (11 (21) are the same), a stronger laminate (6) will be formed by joining them (see FIG. 2).

Furthermore, in the fourth step, the laminate (6) was heated to solidify its integration, and while it was still in a softened state,
This laminate (6) is placed with its outer skin side on a mold (7) which is placed on the parting surface (country side) of a mold (7) and heated to preferably around 100°C.The mold ( 7).

is a plurality of intake holes (9) communicating with the manifold (8).
), and seven manifolds (8) are connected to a vacuum pump (not shown) via a vacuum pipe (IO) (see Figure 3). When the air in the manifold (8) is suctioned and evacuated, it is placed on the mold (7), and the softened laminate (6) is sucked and easily deformed onto the inner surface of the mold (7) while being chemically (See Figure 4). After vacuum forming, the mold (7) is heated to 50° to 60'
The molded product (12) is removed from the mold (7).

Note that instead of the vacuum forming described above, it is also possible to adopt a means of pressure forming, in which pressurized air of 4 to 5 Ky/ctd is similarly jetted onto the mold surface.

The second embodiment shown below describes a molded product formed by integrally covering the surface of a core body with cloth as a skin body.

The cloth used for the skin at this time was polypropylene,
The fabric may be made of woven or knitted fabrics such as polyester, nylon, or acrylic, and blended yarn or crimped yarn is used as the constituent yarn of these fabrics. It is desirable that this cloth has sufficient flexibility (7) and stretchability, and one of the most suitable cloths is, for example, tricot knitted from semi-stretched polyester yarn.

As the core, the thermoplastic resin sheet described in detail in the first embodiment is used.The fabric sheet and the resin sheet are each cut to a predetermined size, and each material is heated with an oven heater or the like to form the core. The body sheet is heated until it approaches a melt state. More specifically, in the case of a core made of polypropylene, its surface temperature is heated to around 160°C, and in the case of cloth, it is heated to 100' to 110'C.

To activate the bonding of each member of the heat-treated image material, first place the cloth just after heating on the parting surface of the molding mold.
Lay the core on top of it. The cloth and core body to be placed on the mold may be stacked in advance to form a laminate before being placed on the mold, and this may be placed integrally with the right side facing the parting surface of the mold. After placing the laminate on the mold, the manifold inside the mold is evacuated, and the laminate is brought into suction deformation and pressure contact with the mold surface. As a result, a part of the melted core sheet is bitten into the woven structure of the cloth, and physical integration is realized. The mold is then cooled to 50' to 60°C, and the molded product is removed from the mold. Of course, instead of the vacuum forming described in the first embodiment, pressure forming by blowing out pressurized air is also possible.

(Effects of the Invention) The present invention uses a thermoplastic resin sheet as a constituent material of the core body, and a flexible sheet as a constituent material of the skin body, and actively utilizes the melting tendency generated by heat treatment of these two sheets. In addition, by using the thermoplasticity of the core material, the melting of the art material by heat treatment of the skin material and the core material, and the easy deformability, it is possible to apply vacuum suction or air pressure to the surface of the mold. By synchronously achieving the adhesion of both materials and the deformability centered on the core, there is no need for any special bonding process between the core and skin as in the past, and the thermoplasticity of the core By utilizing deformation and subsequent shape retention, work efficiency can be further improved.

[Brief explanation of the drawing]

1 to 4 are longitudinal cross-sectional views showing the stepwise molding process when the present invention is carried out, and FIG. 5 is a cross-sectional view of a molded product obtained according to the present invention. In the figure, (1) is the core body skin), (21 is the composite skin, (3
) is a sheet for forming a solid layer, (4) is a sheet for forming a foam layer, (6) is a laminate, (7) is a mold for vacuum forming, (9)
indicates an intake hole, and (12) indicates a molded product.

Claims (3)

[Claims] (1) The thermoplastic resin core sheet and the skin sheet are each heat-treated until the core sheet approaches a melting state, and both sheets under the heat retention condition are laminated on a molding mold. A method for manufacturing a molded product with a skin, in which the laminate is placed on the side of a mold and pressure-molded using air pressure. (2) The method for producing a molded article with a skin according to claim 1, wherein the skin sheet is constituted by a composite laminate of a solid layer and a foam layer. (3) The method for producing a molded article with a skin according to claim 1, wherein the skin sheet is made of a highly elastic woven or knitted fabric.