JPS61233513A - Preparation of cushion material - Google Patents

Abstract

PURPOSE:To enhance productivity by preventing the generation of a cavity, a reduced wall thickness or a crack, by fixing a soft or semi-hard polyurethane foam slab processed so as to have the shape of a seat part in a seat part molding space by a weir member before injecting an expandable polyurethane stock solution to expand the same. CONSTITUTION:A polyurethane foam slab 7 processed so as to have a shape corresponding to the seat part of a cushion material is arranged and fixed to the seat part molding surface of a lower mold 3 by a weir member 6. The polyurethane slab 7 has air permeability of 80cc/cm<2>/sec or more, the number of cells of 30/25mm and hardness of 7kg/JIS. Subsequently, an expandable polyurethane stock solution 5 is injected in a side part molding space and an upper mold 4 is closed to expand said stock solution. After expansion and curing were finished, the expanded polyurethane is demolded to obtain a cushion material wherein a seat part 7 and a side part 8 are integrated by an impregnated layer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in the method of manufacturing a cushioning material, particularly a cushioning material having a seat portion and a side portion.

[Conventional technology]

As shown in Figure 2 (A), polyurethane foam cushioning material consisting of a seating part l and side parts 2 has been widely used in automobile seats etc. because the presence of the side parts 2 provides a good holding feeling. has been done.

This cushion material is applied to the lower mold 3 as shown in Figure 2 CB).
It is manufactured by foam molding using a mold consisting of an upper mold 4 and a molding chamber corresponding to the outer shape of the cushion material.

That is, a polyurethane foaming stock solution 5 containing necessary components such as an organic incyanate component, a polyol component, and a tin catalyst is injected into the molding chamber of the lower mold 3, and the mold is closed with the upper mold 4 and foamed. The foam expands and fills the molding chamber, and is molded into the shape of the cushion material shown in FIG. 2(A).

Note that the upper mold 4 is provided with a large number of gas vent holes (not shown) in order to release a large amount of foaming gas generated during one foaming process to the outside of the mold.

[Problem that the invention seeks to solve]

When using conventional manufacturing methods, even when gas vent holes are provided as described above, the shape and thickness of the molded product
Alternatively, depending on the foaming conditions, etc., it is not possible to completely prevent the formation of cavities due to gas accumulation, and the foaming stock solution along with the foaming gas is ejected from the gas vent hole, resulting in frequent problems of underfilling and cracks.

When such a problem occurs, it is necessary to repair the missing parts, and the extra labor involved is actually seriously hindering productivity.

[Means for solving problems]

The method for manufacturing a cushion material according to the present invention uses a cushion material mold having a front seat molding space and a side molding space, and a weir member is erected on the molding surface at the boundary between the two molding spaces, and a predetermined seating position. After fixing a soft or semi-rigid polyurethane foam slab processed into a shape into the seating part molding space by the ridge member, a polyurethane foam stock solution is injected into the side molding space and foamed to form the side part. It is characterized by forming a polyurethane foam layer filling the molding space and impregnating the polyurethane foam installed in the front seat molding space with a polyurethane foam stock solution to obtain a molded product in which the seating part and the side parts are integrated. It is something.

The key point of the present invention is that a polyurethane foam slab that has been previously processed into the shape of the seat is placed in the front seat molding space of the mold and molded.

This polyurethane foam slab has 1 breathability and 8
It is desirable to use a material with an air permeability of 0 cc/am2/sec or more, more preferably an air permeability of 120 cc/am2/sec.
ta 2/sac or more and the number of cells is 50 (Il/25m
It is desirable to use one with a diameter of m or less.

[Effect]

In the case of the manufacturing method of the present invention, the gas generated by foaming the polyurethane foaming stock solution is not only dispersed outside the mold through the gas vent hole, but also absorbed into the bubbles of the urethane foam installed in the seat molding space in advance. It is possible to prevent the formation of cavities due to gas accumulation.

Further, since the expanded foaming stock solution comes into contact with the polyurethane foam and is impregnated into the bubbles, it is suppressed from ejecting out of the mold along with the gas, and the occurrence of underfilling and cracks is also prevented.

As a result of impregnation with this foaming stock solution, the pre-installed polyurethane foam and the polyurethane foam formed by foam molding are integrated.In addition, in the present invention, the hardness of the seating part and the side parts can be easily changed. I can do it. Therefore, it is possible to obtain the optimum hardness required for each part in terms of function.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1(A) and 1(B).

In this example, a mold similar to that shown in FIG. 2(B) was used, but as shown in the figure, a dam member 6 protruded on the lower mold surface at the boundary between the front seat molding space and the side molding space. They are different in how they are set up.

First, a polyurethane foam slab 7 processed into a shape corresponding to the intended seating part of the cushion material is installed and fixed on the seating part molding surface of the lower mold 3 using the dam member 6 . The polyurethane foam slab 7 has an air permeability of 120
cc/cm2/sea, number of cells 30/25
■■ A hardness of 7 kg/JIS was used.

Then, in the side molding space of the lower mold 3, a polyurethane foam according to the following formulation was added.

The mold was closed with upper mold 4 and foamed.

H2O3,5// Tolylenediamine 0.1 //N-
Nithylmorpholine 1.0 Dibutyltin dilaurate 0.09 //Silicone oil
! , 5〃Tolylene diisocyanate)
44.0 /1 When the mold was removed after foaming and curing, the seating part 7 and side part 8 were removed as shown in Figure 1 (B).
The hardness of the seating part 7 is 7 kg/JIS as mentioned above, and the desired cushioning material is obtained in which the cushioning material is integrated with the impregnated layer 9.
In contrast, the hardness of the side portion 9 was 13 kg/JTS. In addition, a groove 10, which is a trace of the weir member 6, was formed between the seating part 7 and the side part 9 in this cushion material.

In the above embodiments, the occurrence of cavities, cracks, lack of thickness, etc. was significantly less than in conventional manufacturing methods, and almost no repair process was required.

In addition, the cushion material obtained in the above example has a seating part 7.
A groove 10 is formed at the boundary between the side portion 9 and the side portion 9, and the existence of this groove provides the ability to follow displacement in the lateral direction, resulting in the effect of improving cushioning properties.

In addition, there is a method for fixing the polyurethane foam step 7, which has been previously processed into the shape of the seating part, on a predetermined position on the lower mold surface. A method such as inserting it into a planted bottle can be used.

〔Effect of the invention〕

As detailed above, according to the present invention, when manufacturing a cushion material with a seating portion and side portions by molding, it is possible to prevent the occurrence of cavities, lack of thickness, or cracks, and to improve productivity by eliminating the need for repair processes. It is possible to obtain remarkable effects such as being able to improve

[Brief explanation of the drawing]

Figures 1 (A) and (B) are cross-sectional views for explaining the manufacturing method of a rare resin material, which is an embodiment of the present invention, and Figure 2 (A) is an object to which the present invention is applied. 1 is a cross-sectional view of a cushioning material, and FIG. 2B is a cross-sectional view for explaining a conventional manufacturing method thereof. 1... Seating part, 2, 9... Side part, 3... Lower mold, 4
...Top mold, 5...Polyurethane foam stock solution, 6...
Weir member, 7... Polyurethane foam slab, 8...
・Impregnated layer, 10... Patent attorney Takehiko Suzue, attorney for the applicant, Riku C.

Claims (3)

[Claims] (1) After fixing a soft or semi-rigid polyurethane foam slab processed into a predetermined seating shape into the seating molding space using a cushion material mold having a seating molding space and a side molding space, A polyurethane foam stock solution is injected into the side molding space and foamed to form a polyurethane foam layer filling the side molding space, and the polyurethane foam disposed in the seating molding space is impregnated with the polyurethane foam stock solution. A method for producing a cushioning material, comprising obtaining a molded body in which a seating portion and a side portion are integrated. (2) The method for manufacturing a cushioning material according to claim (1), wherein the soft or semi-rigid polyurethane foam slab has an air permeability of 80 cc/cm^2/sec or more. (3) Using a mold for cushioning material with a weir member erected on the molding surface at the boundary of both molding spaces, a soft or semi-hard polyurethane foam slab processed into the predetermined seating shape is placed on the seat by means of the weir member. A method for manufacturing a cushion material according to claim 1 or claim 2, wherein the cushion material is fixed within a molding space.