JPH0428523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing sheets used in vehicles such as automobiles and trains, aircraft, ships, furniture sofas, and the like.

<Prior Art> The above-mentioned sheets are manufactured by covering a cushion body, such as a foamed polyurethane foam, with a skin. This sheet is manufactured by injecting a foaming solution into a foaming mold to form a sheet-shaped cushion body, and after removing the molded cushion body from the mold, a skin is adhered to the outer surface of the cushion body. (Special Publication No. 59-40037).
This method allows the skin to firmly adhere and integrate with the cushion body, making it possible to mold even shapes with complex uneven surfaces, expanding the degree of freedom in the design of the seat, and preventing wrinkles from forming on the skin. It is a useful method that improves aesthetic appearance.

<Problems to be Solved by the Invention> In the above method, a release agent for demolding is applied to the inner surface of the foam mold before the cushion body is taken out from the foam mold. There is. Therefore, as shown in FIG. 4, a certain amount of mold release agent 8 adheres to the outer surface of the cushion body 7 taken out from the mold. However, since the release agent 8 has the opposite properties to that of the adhesive, it has an adverse effect on the adhesion of the skin. For this reason, a step of removing the mold release agent adhering to the cushion body is required before adhering the skin, which increases the number of steps. Moreover, when the cushion body has a complicated shape, it is difficult to remove the mold release agent, reducing workability, and if parts remain that cannot be completely removed, there is a problem in that poor adhesion of the skin will occur.

An object of the present invention is to provide a method for manufacturing a sheet that solves the above problems and eliminates the adverse effects of a mold release agent.

<Means for Solving the Problems> In order to achieve the above object, the present invention uses a hot melt adhesive that is deactivated during foam molding as a substitute for a mold release agent, and also utilizes this hot melt adhesive. The outer skin and the cushion body are bonded together. That is, the sheet manufacturing method according to the present invention includes forming an adhesive layer made of a hot melt adhesive that is inactivated during foam molding on the inner surface of a foam mold, and then foaming a foaming stock solution in the foam mold. The invention is characterized in that a cushion body with the adhesive layer integrated on its outer surface is molded, a skin is coated on the cushion body, and the adhesive layer is heated and melted to adhere the cushion body and the skin.

<Function> Hot melt adhesive loses its adhesive strength during foam molding. Therefore, the hot melt adhesive set in the form of a film or web on the inner surface of the foam mold is
It does not have any adhesive force and is interposed between the cushion body and the mold and performs the same function as a mold release agent. on the other hand,
When hot melt adhesive is heated, it melts and functions as an adhesive. Therefore, when the skin is applied to the cushion body and heated, the skin and the cushion body are bonded together.

<Examples> The present invention will be specifically described below based on illustrated examples.

In the present invention, prior to foam molding of the cushion body,
An adhesive layer made of a hot melt adhesive that is inactivated during foam molding is formed on the inner surface of the foam mold. FIG. 1 shows a cross-sectional view of this process. The foam mold 1 consists of a lower mold 2 and an upper mold 3.
A foaming chamber 4 that matches the shape of the top surface of the sheet is formed in the upper die 3, and an uneven portion that matches the shape of the back surface of the sheet is formed in the upper mold 3. Therefore, when the upper mold 3 is assembled to the lower mold 2, a cavity corresponding to the outer shape of the sheet is formed. An adhesive layer 5 made of a hot melt adhesive is formed on the inner surface of the foaming chamber 4 of the lower mold 2. The adhesive layer 5 is formed by forming a hot-melt adhesive into a film or web, and setting the adhesive on the inner surface of the foaming chamber 4. here,
In the case of a web shape, since the contact area between the adhesive layer 5 and the foaming mold is small, the foamed cushion body can be easily removed from the mold. Further, the adhesive layer 5 may be formed by cutting a hot melt film and setting it.
The hot-melt adhesive may be dissolved or dispersed in a suitable solvent, sprayed onto a foam mold, or applied with a brush, and then the solvent may be evaporated. In the case of spray coating, etc., time is required for the solvent to volatilize, but the adhesive layer 5
It has the advantage that it can be formed uniformly over the entire surface of the foam mold. In addition, in the case shown in the first figure, the adhesive layer 5
is formed only on the upper surface of the lower mold 2, i.e., the seating portion of the cushion body to be foam-molded, but is not limited to this, and may be formed on the entire inner surface of the lower mold 2 or the lower surface of the upper mold 3. .

A foaming solution is injected into the foaming mold 1 on which the adhesive layer 5 has been formed in this manner, and a cushion body 6 having a predetermined shape is formed. As the foaming stock solution, an appropriate resin such as polyurethane resin is selected. FIG. 2 is a cross-sectional view during foam molding, and an adhesive layer 5 made of a hot melt adhesive is interposed between the molded cushion body 6 and the foam mold 1.
Moreover, since the adhesive force of the adhesive layer 5 is deactivated during foam molding, it acts like a so-called mold release agent, and the cushion body 6 can be easily demolded. After such demolding, as shown in FIG. 3, the adhesive layer 5 is integrated with the seating portion of the cushion body 6, and the state is the same as when an adhesive is applied to the cushion body 6. Therefore, when the cushion body 6 after demolding is coated with a skin (not shown) and then the adhesive layer 5 portion is heated, the adhesive layer 5 is melted and adhesive force is imparted to the skin and the cushion body 6. Good and reliable adhesion is achieved. As a result, the cushion body and the skin can be reliably joined even if the sheet has a complicated shape, increasing the degree of freedom in design.

In addition, when foam molding the cushion body 6, the foaming mold may be heated to shorten the foaming time, but in this case, the heating temperature is below the temperature at which the adhesive force of the adhesive layer 5 is imparted. It will be held in Further, when adhering the outer skin and the cushion, pressing may be performed to promote adhesion.

<Effects of the Invention> As described above, according to the present invention, an adhesive layer made of a hot-melt adhesive is formed on the inner surface of a foam mold as a substitute for a mold release agent, and the mold release agent is omitted, thereby eliminating the adverse effects of the mold release agent. There is no need to remove the mold release agent. In addition, since the adhesive layer was heated to bond the cushion body and the skin, it was easier to form the sheet.
The degree of freedom in shape selection is also expanded. Furthermore, since the hot melt adhesive of the present invention uses a high melting point adhesive that is inactivated during foam molding, the heat resistance of the sheet after molding is improved and there is no problem of the adhesive oozing out during use.

[Brief explanation of drawings]

1 and 2 are sectional views of the manufacturing process of the present invention, FIG. 3 is a perspective view of the cushion body after demolding, and FIG. 4 is a sectional view of the cushion body obtained by the conventional method. 1... Foaming mold, 5... Adhesive layer, 6... Cushion body.

Claims (1)

[Claims] 1. After forming an adhesive layer made of a hot-melt adhesive that is deactivated during foam molding on the inner surface of a foam mold, a foaming stock solution is foamed in the foam mold to integrate the adhesive layer on the outer surface. 1. A method for producing a sheet, which comprises forming a cushion body, coating the cushion body with a skin, and heating and melting an adhesive layer to adhere the cushion body and the skin.