JPS6012205B2 - Manufacturing method of cushion body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a cushion body used in seats, furniture, etc.

FIG. 9 is an explanatory diagram of a general manufacturing method for this type of cushion body.

In the figure, a cushion body 21 made of polyurethane resin
The foaming mold 22 consists of a lower mold 23 and an upper mold 25 having an air/gas vent hole 24 on the lower mold 23 for opening the warply mold. When the cushion body 21 is foam-molded using the mold 22, the excessively injected polyurethane resin foam stock solution flows out through the holes 24 to the outside. The cushion body obtained in this way has the following characteristics:
Physical properties, economic efficiency, etc. are related to the number, position, and shape of the holes 24. That is, as the number and diameter of the holes 24 are increased, the quality of the cushion body improves, but excessive use of the undiluted solution deteriorates product quality. If the number and diameter of the holes 24 are reversed, the yield will be improved, but air pockets will remain in the cushion body, resulting in a decrease in quality. Cushion portion 21 around the outflow 26 of the cushion body 21
A becomes harder than other parts and deteriorates various properties. Further, the gushing portion 26 must be removed in a subsequent process, which is uneconomical. The present invention was made in view of the above-mentioned drawbacks, and its purpose is to provide a method for manufacturing a cushion body with excellent physical properties and various characteristics. Another object of the present invention is to provide a method for manufacturing a cushion body that improves product yield, and a method for manufacturing a cushion body that simplifies post-processing and improves productivity.

The gist of the present invention is to provide a foaming mold comprising a lower mold and an upper mold which is closed on the lower mold and having a molding space of a required volume, and a recess for an air reservoir in the main part of the upper mold surface of the mold. A foaming mold for the cushion body is formed by providing a foaming mold for the cushion body, and the necessary amount of synthetic resin foam stock solution is injected into the lower mold of the mold, and the upper mold is closed as a layered mold. It is characterized in that it is sequentially filled and foamed, and the air pressure in the recess and the pressure of the cushion molded body in the space are balanced at the boundary between the recess and the space.

Hereinafter, embodiments of the present invention will be described in detail with reference to the illustrative diagrams of FIGS. 1 to 8.

In the figure, 1 is a foam molding mold 2 for a cushion body (made of polyurethane foam) for seats, furniture, etc., used in the method of the present invention. The mold 1 consists of a lower mold 3 and an upper mold 4 that is closed over the lower mold 3, and the required volume V0 (approximately 20,000 in this example) formed by the upper and lower molds 3 and 4 is molded. The cushion body 2 is foam-molded by foaming the polyurethane resin foam stock solution 2a within the space 5. Then, the mold 1 transfers its total volume V to the space 6 on the mold surface 6a of the upper mold 4, which faces the substantially horizontal final foaming rising surface 2c of the cushion molded body 2b during the rising process due to foaming of the stock solution 2a. An air reservoir recess 7 having a volume of 1 to 10% (approximately 780 in this embodiment) of the volume VO of the portion 5 is provided. As shown in the figure, the mold surface 6 of the upper mold is suitably fan-flat, concave, convex, inclined, or the like.

The air reservoir recess 7 is made up of individual recesses 7a, grooves 7b, or a combination thereof, and the volume V of the recess 7 is the sum of the volumes Vi of the recesses 7a, grooves 7b, etc. Although the shapes of the recesses 7a and the grooves 7b are not particularly limited, for example, the recesses 7a are suitably trigonal, quadrangular pyramids, polygonal pyramids, hemispheres, columns, and other conical shapes. It is desirable that the grooves 7b and 7b are adjacent to each other.The recess 7a in FIG. It is.

The groove 7b in FIG. 5 is a groove with a triangular cross section. This cross section may be square, semicircular, etc. Next, a method for manufacturing the cushion body 2 using the mold 1 will be described.

A necessary amount of the foam stock solution 2a (formulation example of the stock solution and injection amount will be described later) prepared to foam and fill the space 5 at the required density is injected into the lower mold 3 of the mold 1. The upper mold 4 is closed on the lower mold 3 in a sealed manner, and the space 5 is sequentially filled with the substantially horizontal foaming rise of the stock solution 2a, resulting in foam molding.
In addition, the air pressure P driven into the recess 7 and the foaming pressure PO of the cushion molded body 2d in the space 6 are balanced at the boundary L' between the recess and the space, and the cushion molded body 2d is forced into the recess 7. The cushion body 2 for the seat is obtained by foaming and maturing while preventing the foam from being introduced into the cellar. In this invention, the portion of the cushion body 2 corresponding to the boundary L is a substantially smooth surface and is equivalent to other molded surfaces.

The cushion body 2 is sealed by the recess 7a and the groove 7b.
The more you place, the better. In the present invention, an auxiliary material such as a Hessian cloth may be interposed along the boundary L' before forming. The foam stock solution 2 used in this invention
Examples of the formulation of a are shown in the table below.

In addition, 640 groups of the above-mentioned formulations were injected.

The weight of the cushion body 2 after foam molding is 6008.
Met. That is, according to the present invention, the product yield is 93%. This is due to the fact that foam molding is performed with the upper and lower molds 3 and 4 sealed and that the stock solution does not gush out. In the conventional method, the product yield is poor at 88 to 89% due to burrs generated between the upper and lower molds, seepage of the stock solution, etc. According to this invention, the whisker phenomenon that sometimes occurs in the subordinate method,
There is no hard cushion portion 21a around the outflow 26, no air pockets, etc., and the physical properties and various characteristic values of the cushion body 2 are extremely good. In this invention, unlike the conventional method, there is no need to remove the 26 portions of the effect in a post-process, so the number of steps is simplified and productivity is improved. As described above, according to the present invention, problems such as poor product quality, product quality, and productivity, which are disadvantages of the conventional method, can be solved all at once, and its utility value is great.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the mold with the stock solution injected, Figure 2
The figure is a diagram of the state during foam molding, Figures 3 and 4 are enlarged perspective views of the main parts showing the air reservoir recesses, Figure 5 is a sectional view of another mold, and Figure 6 is the main part of Figure 2. Fig. 7 is an enlarged view of the circular part in Fig. 6, Fig. 8 is a perspective view of the cushion body, Fig. 9
The figure is an explanatory diagram of the subordinate method. 1... Foaming mold, 3... Lower mold, 4...
... Upper mold, 7 ... Air reservoir recess, V.
...Volume of the recess, VO...Volume of the molding space, V
i...Volume of depression and groove, P...Air pressure, P0...Pressure of space cushion molded body, L
······boundary. Leopard 1 Kyoren 2 Hato Tsutomu 3 Mother * Mu Mother 5 Evil * 6 Mother Tsutomu 7 Mother * 8 Spot * 9 Crab

Claims (1)

[Claims] 1 A mold for molding a cushion body by foaming a synthetic resin foam stock solution in a molding space of a required volume formed by the lower mold and the upper mold placed on the lower mold, An air reservoir whose total volume is 1 to 10% of the space in the upper die surface of the mold corresponding to the substantially horizontal final foaming rising surface of the cushion molded body during the rising process due to foaming of the stock solution. A concave portion is provided to form a foam molding mold for the cushion body, and the necessary amount of the stock solution prepared to foam and fill the space at the desired density is poured into the lower mold of the mold, and the upper mold is sealed on the lower mold. The mold is placed in a shape and the mold is closed, and the space is sequentially filled with the substantially horizontal foaming rise of the stock solution to form foam molding, and the air pressure in the recess and the pressure of the cushion molded product in the space are balanced at the boundary between the recess and the space. A method for producing a cushion body, characterized in that aging is carried out by equilibrating and preventing the cushion molded body from being press-fitted into a recess.