JPH0255111A - Preparation of skin integrated foamed molded product - Google Patents

Abstract

PURPOSE:To prevent the partial generation of a cavity on the surface of a skin without widening the interval between the skin and a core material by forming a non-foamed or low-foamed resin layer to the inner surface of the skin and subsequently placing the core material on the resin layer in such a state that the resin layer is yet foamed and integrating the skin and the core material by the foaming of the resin layer. CONSTITUTION:A skin 10 is placed on a predetermined lower mold 12 and a core material 14 is applied to an upper mold 16 and, in such a state that the upper mold 16 is opened, a foamable raw material 18 such as a polyurethane foam raw material is sprayed to the whole of the inner surface of the skin 10 of the lower mold 12 to form a non-foamed or low-foamed resin layer 20 to the inner surface of the skin. If necessary, an adhesive is preliminarily applied to the inner surface of the skin 10 or core material 14. Next, when the resin layer 20 is in a yet foamed state, the lower mold 12 is covered with the upper mold 16. By this method, the core material 14 is placed on the resin layer 12 formed to the inner surface of the skin 10. The resin 20 form a foam body by foaming to integrate the skin 10 and the core body 14 through the foam body.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention provides a method for manufacturing a skin-integrated foam molded product, which integrally manufactures a foam molded product in which a foam layer is sandwiched between a skin and a core material. Regarding.

(Prior Art) In consideration of safety, automobile instrument panel pads and the like usually have a foam layer such as V-urethane foam sandwiched between a core material and an outer skin.

The following method is used for manufacturing it.

One method is to set the skin, which has been shaped or molded in advance by vacuum forming or slush molding, into a specified foam mold (lower mold), place the core material into the upper mold, and then 120421, a predetermined amount of a liquid foaming material such as polyurethane is injected into a predetermined position on the skin, the upper mold is closed, and the foam is expanded into the gap between the skin and the core material by foaming the foaming material. This is a method (oven injection system) in which the skin and core material are formed and integrated.

Another method, as disclosed in JP-A No. 56-115232, is to install a core material in an upper mold, close the mold, and then inject liquid foaming raw material between the skin and the core material to lock them together. method (closed injection system).

In this way, in the above two methods, the foaming material is injected with the mold open, but although the foaming material is injected with the mold closed, in both methods, the foaming material injected is
What they have in common is that they form a foam by filling the gap (space) between the skin and core material as if it were flowing.

(Problem to be Solved by the Invention) By the way, even if a foaming raw material such as polyurethane is initially liquid, it increases in viscosity through a subsequent reaction, and the viscosity increases due to the increased viscosity of the liquid polymer. It becomes a foam by sealing in the foaming gas mixed into the foam.

Therefore, in the above two methods in which the foaming material flows through the gap between the skin and the core material to fill the gap, the foaming material flows in the narrow part between the skin and the core material. There is a tendency for the foam to become difficult, to partially lack the foam, or to entrap air. Particularly in the case of skins made by slush molding, powdered or liquid raw materials are poured into a heated mold and melted and molded using heat.
The surface that is molded by adhering to the mold surface is molded into a predetermined grained surface, etc., but the back surface is not regulated and becomes a continuous surface with minute irregularities, making the above problems more likely to occur. There is.

This lack of foam or the entrainment of air creates a cavity under the skin, resulting in a defect in the molded product where the skin is partially depressed. Therefore, a design is usually made to maintain a constant distance between the skin and the core material so that the raw material can flow even when the viscosity of the raw material increases.

However, it is undeniable that this increases the volume between the skin and the core material, and since foaming raw materials such as polyurethane are generally expensive, the unit price of the product tends to be high as well.

Therefore, the present invention aims to provide a method for manufacturing a skin-integrated foam molded product that can prevent the occurrence of partial depressions on the skin surface without increasing the distance between the skin and the core material.

(Means for Solving the Problems) The gist of the present invention to achieve the above object is to spray a foaming raw material onto the inner surface of the skin that has been shaped or molded into a predetermined shape, and to form an unfoamed or low-foamed resin layer on the inner surface of the skin. After formation, a core material is placed on the resin layer while the resin layer is still in a foamed state, and the skin and the core material are integrated by foaming the resin layer. It is in the manufacturing method.

(Function) In this invention, a foaming raw material is first sprayed onto the inner surface of the skin, and an unfoamed or low-foamed resin layer is formed on the inner surface of the skin at the sprayed portion. That is, the resin layer is formed on the inner surface of the skin without the foaming raw material flowing. As a result, there is no risk of air being trapped or cavities being created between the resin layer and the skin.

The unfoamed or low-foamed resin layer thus formed on the inner surface of the skin then begins to foam or foams further. Since the core material is placed on the resin layer while the resin layer is still in a foamed state, the foamed resin layer and the core material are in close contact with each other, and the resin layer is foamed and hardened to form a bond between the skin and the core material. become unified. That is, a skin-integrated foam molded product is formed in which the foam is sandwiched between the skin and the core material.

(Example) Examples of the present invention will be described below.

FIGS. 1 to 4 are process diagrams for manufacturing a skin-integrated foam molded product according to an embodiment of the present invention.

First, a skin of a predetermined shape is formed by vacuum forming, slush forming, or the like. Next, as shown in FIG. 1, the skin 10 is placed on a predetermined lower mold 12, and a core material 14 made of metal, plastic, etc. is placed on an upper mold 16.

Then, with the upper mold 16 opened, the lower mold 1
A foaming raw material 18 such as a polyurethane foam raw material is sprayed onto the entire inner surface of the skin 10 of No. 2 to form an unfoamed or low-foamed resin layer 20 on the inner surface of the skin. At that time, if necessary,
Adhesive is applied to the inner surface of the skin 10 or the core material 14 in advance.6 The resin layer 20 formed on the inner surface of the skin 10 starts foaming if it is in an unfoamed state, and further foams if it is in a low foaming state.

Next, while the resin N20 is still in a foamed state, the upper mold 16 is placed over the lower mold 12 as shown in FIG. As a result, the core material 14 is placed on the resin layer 20 on the inner surface of the skin 10. Then, the resin layer 20 becomes a foam by foaming, and the skin 10 and the core material 14 are integrated through the foam. After that, if the molded product is removed from the mold, the fourth
A desired skin-integrated foam molded product 22 as shown in the figure is obtained. 24 in the figure is a foam.

(Effects) This invention forms a resin layer by spraying a foaming raw material on the inner surface of the skin, and when the resin layer is still in a foamed state, a core material is placed on the resin layer to produce a skin-integrated foam molded product. It manufactures.

Therefore, since the resin layer does not need to flow through the gap between the skin and the core material, there is no risk of foam loss or air entrainment that would otherwise occur due to difficulty in flow. As a result, no voids or voids were generated inside the skin of the resulting skin-integrated foam molded product, and it was possible to prevent the skin from sinking.

In addition, since there is no need to widen the gap between the skin and the core material to improve the fluidity of the foaming material, the capacity between the skin and the core material does not increase, and the amount of expensive foaming material used can be reduced. There are also effects that can be reduced.

[Brief explanation of the drawing]

1 to 4 are process diagrams for one embodiment of the present invention.

Claims (1)

[Claims] A foaming raw material is sprayed onto the inner surface of the skin that has been shaped or molded into a predetermined shape to form an unfoamed or low-foamed resin layer on the inner surface of the skin, and then, while the resin layer is still in a foamed state, the foaming material is sprayed onto the inner surface of the skin. 1. A method for manufacturing a skin-integrated foam molded product, which comprises placing a core material and integrating the skin and the core material by foaming the resin layer.