JPS6235810A - Manufacture of expansion molded part - Google Patents

Abstract

PURPOSE:To manufacture an expansion molded part with no flow of raw material into openings by a method wherein the openings of a core material are partitioned by air-permeable foams which are pasted along the peripheries of the openings of the core material. CONSTITUTION:An air-permeable foam 14 consists of a string-shaped matter mainly made of open cell foam such as soft urethane foam and is pasted along the peripheries of the openings 18 of a core material 12 by means of adhesive 20 such as double-coated tape so as to partition the openings from a cavity made between a core material 12 and a skin material 16 when foaming molds 10 are closed. In this case, the thickness of the air-permeable foam 14 is selected so as to be sligtly compressed by the core material 12 and the skin material 16. Liquid expandable raw material such as urethane foam raw material is poured in the cavity between the core material 12 and the skin material 16 through a pouring nozzle 22 in order to be expanded. The air in the cavity passes through the foam 14 on account of the air-permeability of the air-permeable foam 14 which partitions the openings 18, so as to easily escape through the openings 18. The liquid expandable raw material turns into cream-like viscous fluid during expansion and can not pass through the air-permeable foam 14 and finally turns into cushioning foam 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of manufacturing a foam molded product having an opening such as an automobile instrument panel, a door trim, or the like.

(Prior Art) Automotive interior parts such as instrument panels, door trims, console boxes, etc. are generally composed of a skin material, a cushioning foam, and a core material. and a core material are set, and a liquid foaming raw material such as urethane foam is injected between the two and foamed to form an integrated structure.

By the way, as shown in Fig. 4, the door trim requires an opening to secure the armrest or handle, and the instrument panel (not shown) requires an opening to secure the meters. In some cases, integral molding was performed as described above using a core material with an opening in advance. However, the opening was closed due to the foaming of the liquid foaming raw material, or the back side of the core material was formed from the opening. The raw materials were passed around, and it took a lot of man-hours to finish them. Further, the raw material flowing into such an opening results in a loss, and it cannot be said to be economically preferable.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a method for producing a foamed molded product without the raw material flowing into the opening.

(Means for Solving the Problems) The gist of the present invention is to inject a liquid foaming raw material between a core material having an opening and a skin material, and foaming the liquid raw material. In the method of manufacturing a foam molded product that is integrated with a skin material, a breathable foam is adhered around the core opening, and the core opening is defined by the foam.

(Function) Breathable foam is made up of fine pores inside and on the surface that are mostly interconnected, and while it allows air to flow freely, it hardly allows the flow of cream-like viscous liquid. It does not allow it and only allows for slight impregnation.

Therefore, in the cavity of the foaming mold in which the core material and the skin material are set and the liquid foaming material is injected, the air that must be expelled during foaming of the liquid foaming material passes through the breathable foam around the opening of the core material. It is easy to convert base numbers. On the other hand, the liquid foaming raw material becomes a cream-like viscous liquid during the foaming process, so although it impregnates the breathable foam, it hardly flows out into the openings. In addition, as the air permeable foam and the skin material are bonded together by the hardening of the liquid foaming material impregnated into the air permeable foam, the finished molded product with the skin material at the opening removed will have a large area around the opening. There is no risk of lifting of the skin material.

(Example) FIG. 1 is a sectional view of a foaming mold before injection of a liquid foaming material in an example of this invention. In the figure, 10 is a foam type, 12 is a core material, 14 is a breathable foam, and 16 is a skin material.

The foaming mold 10 has a product-shaped cavity, and a core material 12 and a skin material 16 are set on the cavity surface.

The core material 12 is made of a shape-retainable material such as a metal plate, hardboard, particle board, etc., and has an opening 18 at a predetermined position.

The breathable foam 14 is made of a string-like foam material mainly having continuous air holes, such as a soft urethane foam, and is pasted around the opening 18 of the core material 12 with an adhesive such as double-sided tape. When the mold 10 is closed, the core material 12 is removed as shown in FIG.
A cavity and an opening are defined between the surface material 16 and the skin material 16. At this time, the thickness of the breathable foam 14 is selected so that it is slightly compressed by the core material 12 and the skin material 16. Note that 20 in the figure indicates an adhesive.

The skin material 16 is made of a single plastic sheet, a laminate of a plastic film and a fabric, a laminate of a plastic sheet and a foam, or the like.

The foam mold 10 is closed after the core material 12 and the like are set. Then, using the injection nozzle 22, a liquid foaming raw material such as a urethane foam raw material is injected into the cavity between the core material 12 and the skin material 16, and foaming is performed.

Air within the cavity that must be expelled by the foaming of the liquid foam stock passes through the foam 14 and out of the opening 18 due to the permeability of the breathable foam 140 that defines the opening 18 . On the other hand, since the liquid foaming material becomes a cream-like viscous liquid during the foaming process, although it is impregnated into the air permeable foam 14, it cannot pass through the air permeable foam 14 and enters the opening. Almost no outflow occurs, resulting in a cushioning foam 24 as shown in FIG. Then, due to the self-adhesive property of the liquid foaming raw material during foaming and curing, the skin material 16 and the core material 12 become integrated, and at the same time, the opening 18
The surrounding air-permeable foam 14 and skin material 16 adhere at the impregnated portion.

After demolding the foamed molded product thus formed, the skin material is removed along line A-A in FIG. 3 to finish the product.

(Effects of the Invention) As described above, the present invention makes it possible to manufacture a foam molded product having an opening, such as a door trim, without causing liquid foaming raw material to flow out into the opening.

Therefore, according to the present invention, there is no need for a finishing operation to remove the particles formed from the raw material flowing out from the opening of the foam molded product, and almost no raw material is wasted.
It has excellent effects in terms of workability and economy.

[Brief explanation of the drawing]

Figures 1 to 3 relate to an embodiment of the present invention. Figure 1 is a cross-sectional view of a foaming mold before injection of liquid foaming raw material. Figure 2 is an enlarged cross-sectional view of the main part when the mold is closed. Figure 3 is a foaming mold. FIG. 4 is an enlarged sectional view of the main part at the time, and FIG. 4 is a perspective view of the door trim. 12 core material, 14-breathable foam, 16 skin material,
18 Opening Patent Applicant: Inoue MCP Co., Ltd. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a method for manufacturing a foam molded product in which a core material and a skin material are integrated by injecting a liquid foaming raw material between a core material and a skin material having an opening and foaming the liquid foaming material, the core material 1. A method for manufacturing a foam molded article, comprising: adhering a breathable foam around the opening, and defining the core opening by the foam.