JPS61293837A - Molding of instrument pad - Google Patents

Abstract

PURPOSE:To improve the moldability of a pad and at the same time enable to prevent the deformation due to heating and the burst of expanded layer by a method wherein composite foam sheets are vacuum-molded by laminating one another so as to abut a surface, onto which non-expanded layer does not be formed, against the rear surface of fabric. CONSTITUTION:In composite foam sheets consisting of polyvinyl chloride foam, onto one surface of which non-expanded layer is formed, the non-expanded layer is located on the surface opposite to the surface contacting with fabric. The 10% modulus of the non-expanded layer is 1-50kg/cm<2>. The skin formed by laminating the fabric skin to the composite foam sheet is shaped with a vacuum molding tool into the desired form, heated up to a slightly higher temperature and vacuum-molded so as to integrally foam-mold said vacuum-molded laminated skin, expandable urethane stock liquid and core material. Consequently, the penetration of expanding liquid into the fabric layer during integral molding and its curing can be prevented. In addition, the deformation due to heating and the burst of the expanded layer can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a method of molding an automobile instrument pad having a fabric skin.

(Prior Art) A method for manufacturing a safety pad for an instrument panel having a fabric skin is known from Japanese Patent Laid-Open No. 59-156748. however.

When integral foam molding is performed using a liquid polyurethane foaming stock solution that has poor moisture content, the polyurethane foaming stock solution penetrates into the fabric tissue under the foaming pressure and hardens the fabric. Because of the grass, there is the problem that the polyurethane foaming solution can enter the surface of the skin through the small gap between the foam mold and the skin and contaminate it, so a base pre-foamed with foamed urethane is used as the instrument pad base material. There was a problem in that it could not be applied to any method other than manufacturing an instrument pad by forming the material and pasting it.

(The main problem to be solved by the invention) This invention involves bonding a polyvinyl chloride foam, which has excellent shape retention and elasticity of the skin after vacuum forming, to the back side of a fabric skin, and vacuum forming it into a desired shape. By forming a non-foamed layer of low modulus polyvinyl chloride with a 10% modulus of 50% or less only on the surface of the polyvinyl chloride foam opposite to the surface in contact with the fabric skin, the vacuum Along with the composite foam sheet laminated fabritta skin, which has a high degree of molding freedom.

The excellent elasticity and shape retention of the skin after vacuum forming not only adheres tightly to the foaming mold when set in the foaming mold and prevents the polyurethane foaming stock solution from going around to the fabric surface side, but also prevents the non-foaming polychloride. The present invention aims to provide a method for molding an instrument pad made of a fabric skin that is beautiful and rich in soft feeling by preventing the presence of a vinyl layer from penetrating the polyurethane foaming stock solution into the fabric skin tissue.

(Means for solving the problem) The fabritta skin material used in this invention is a fabric made of synthetic fibers that can be stretched under low loads and softens at relatively low temperatures, such as woven fabrics, knitted fabrics, or non-woven fabrics. used. Typical examples of such fabrics include Kanekalon (acrylic) manufactured by Kanegafuchi Kagaku and Seiren (acrylic).
Cerito Tricot KKT315 (polyester type) manufactured by Co., Ltd.

Alternatively, commercially available fabrics made of polyurethane elastic fibers interwoven with spandex may be used.

The composite foam sheet used in this application, in which a non-foamed layer of polyvinyl chloride is formed on one side of a polyvinyl chloride foam, has an expansion ratio of 2 to 6 times and a thickness of 0.5 to 2 times.
．． 0ml11, and the thickness of the non-foamed layer is 0.1 to 1.
It is desirable that the length be 5 mm. In particular, in the present application, the presence of the non-foamed polyvinyl chloride sheet layer, the fact that this layer is located on the side opposite to the contact surface with the fabric, and the 10% modulus of the non-foamed layer being 1 to 50%. It is essential that Of course, the 10% modulus of the composite foam sheet as a whole may be in the range of 1 to 50 mm.

The 10% modulus of this unfoamed PVC layer is 5
If the number of glances exceeds 0, the soft feel of the molded instrument pad will be impaired. Also, the lower the 10% modulus, the better, but it is actually limited by the modulus of the fabric skin and the polyvinyl chloride foam.
There is no point in making only the non-foaming layer one hair or less. Furthermore, the polyvinylchloride commonly used for molding instrument pads has a 10% modulus of around 150, and the use of polyvinylchloride with such a high modulus would significantly impair the soft feel, making it unsuitable. .

As a means of obtaining the composite foam sheet as described above,
One side of a 0.5-2.0 mm thick sheet of polyvinyl chloride foam has a 10% modulus of 1-50 (with a thickness of 0
．． It can be made by bonding non-foamed polyvinyl chloride sheets of 1 to 1.5 mm with an adhesive or heat-sealing them. It can also be made by coating one side of a polyvinyl chloride foam sheet with a vinyl chloride sol that forms a non-foaming film with a 10% modulus of 1 to 501 after gelling. Or,
A metal hot plate is pressed onto one or both sides of a commercially available polyvinyl chloride foam sheet to crush the air bubbles on the surface and form a substantially non-foamed layer. You may use it by straining it into 172 pieces. The reason why this application uses a foam sheet in which a non-foamed polyvinyl chloride layer is formed on only one side is because the foaming agent and gas remaining in the bubbles expand due to heating when bonded to the fabric skin and vacuum formed. This is because rupture may occur if the material is deformed or severely damaged.

Any known adhesive can be used for bonding the composite foam sheet and the fabritta skin, as long as the adhesive strength does not significantly decrease due to heating during vacuum forming. In terms of flexibility and heat resistance, polyurethane adhesives are most suitable.

A known method can be used to vacuum form the laminated skin of the fabric skin and the composite foam sheet into the desired shape using a vacuum mold, but since it is laminated with the fabric skin layer, it is possible to vacuum form the skin into the desired shape using a vacuum mold. Compared to the case of a vinyl skin layer, it is necessary to heat and vacuum form at a higher temperature. In this case, the non-foamed polyvinyl chloride layer is arranged so that the heating heat of the polyvinyl chloride foam does not directly hit the cell surface, so even if softening occurs due to high temperatures, the bubbles will not collapse. Because the amount is small, smooth vacuum forming can be performed even by heating at a high temperature.

In addition, PVC foam has insulation properties.

If the thickness is too thick, vacuum forming will be difficult, so it is better to avoid a thickness of 2.0 am or more. Once vacuum-formed, a material with a relatively low expansion ratio of about 2 to 6 times is used, so a molded product with excellent shape retention and elasticity can be obtained.

The core material used for integral foam molding with the thus obtained vacuum-formed laminated skin and the foamable urethane stock solution may be a known material such as metal or ABS (acrylonitrile, butadiene styrene).

ppo (polyphenylene oxide), AS-G (glass fiber reinforced acrylonitrile styrene).

A rigid material made by molding a synthetic resin such as PP-G (glass fiber reinforced polypropylene) into a desired shape is used.

A method for integrally foam-molding an instrument pad using a vacuum-formed laminated skin, a foamable urethane stock solution, and a core material is as follows: 1. For example, the vacuum-formed laminated skin is placed in the lower mold of a polyurethane foam molding mold so that the fabric surface is in contact with the inner surface of the mold. A rigid core material is attached to the inner surface of the upper mold so as to match the shape of the molded skin, and a foaming polyurethane stock solution is injected onto the non-foamed polyvinyl chloride layer surface of the molded skin.
The upper mold may be closed and integral foam molding may be performed.

(Example) Example 1 As a composite foam sheet, a polyvinyl chloride non-foam sheet with a thickness of 0.7 mm was placed on one side of a 1.1 m thick heel quadruple foamed polyvinyl chloride foam sheet manufactured by Konishi Co., Ltd. They were bonded together using KUIO's two-component urethane adhesive, Liquid A and Liquid B. The 10% modulus of the resulting composite foam sheet was 15% as measured using a conventional Schopper type tensile tester. On the side of this composite foam sheet to which the soft non-foamed polyvinyl chloride sheet is not attached, Cerito Tricot KKT315 (polyester fiber) manufactured by Seiren Co., Ltd. is laminated and adhered using the same urethane adhesive as above. A laminated skin material was obtained. Next, set the laminated skin material obtained in - in a vacuum forming machine, set the infrared heater at 320'C, and heat it for 65 seconds at a position 25ca + Ii from the front and back sides of the skin material to adjust the temperature of the fabricator part. After raising the temperature to 150°C, it was brought into contact with a convex vacuum forming mold and vacuum suctioned to perform molding.

The obtained vacuum-formed skin is placed in the lower mold of a polyurethane foam mold.
A rigid core material molded from AS-G resin was set in the upper mold, and a foaming urethane stock solution was injected onto the vacuum-formed skin of the lower mold to perform integral foam molding, and foam was formed on the fabric skin side. An instrument pad with a good fabric skin rich in soft feel was obtained, with no leakage of the urethane stock solution or hardening due to penetration into the fabric tissue.

(Effects of the invention) - The presence of the polyvinyl chloride non-foaming layer formed on one side of the polyvinyl chloride foam prevents the foaming liquid from permeating and hardening into the fabric layer when it is integrally foamed with the foaming polyurethane stock solution. Therefore, the appearance and texture of the fabric will not be damaged.

■ By specifying the 10% modulus of the non-foamed polyvinyl chloride layer in the range of 1 to 50, it has excellent formability when vacuum forming the laminated skin material laminated with fabritta, and the polyvinyl chloride foam By providing a non-foamed layer on only one side of the layer, it is not only possible to prevent deformation due to heating and rupture of the foamed layer, but also to further improve the soft feel of the instrument pad after molding. Ta.

■By combining this foamed layer and non-foamed layer, it is possible to improve shape retention after vacuum forming.

When set in a polyurethane foam mold, it easily adheres to the foam mold (9), so it has the effect of preventing the liquid urethane foam stock solution from going around to the surface side of the 7) blistering skin.

Since it has the following effects, it can be said that this technique is extremely useful in practice.

Claims (1)

[Claims] One side of the PVC foam has a 10% modulus of 1
A composite foam sheet on which a ~50 kg/cm^2 low modulus polyvinyl chloride non-foamed layer has been formed is bonded together with the side on which the non-foamed layer is not formed in contact with the back side of the fabric, and vacuum formed into the desired shape. A molding method for an instrument pad, which comprises setting a shaped skin in a foam mold, and performing three-part foam molding with a core material made of a rigid material.