JPS61125816A - Manufacture of urethane foam molded product - Google Patents

Abstract

PURPOSE:To obtain the product having comfortable use feeling even in the case of a thin cushion, while preventing the occurrence of voids due to accumulated gas by coverting the molding surface into which the vent holes of a mold are drilled, with the polyurethane foam sheet of specified porocity and by foam- molding said polyurethane foam. CONSTITUTION:While covering the molding surface into which the vent holes 3 of a mold are drilled, the polyurethane foam sheet 11 with continuous foam is set thereon, and the spouting of foam stock solution is prevented and thus polyurethane foam is molded integrally with said porous sheet. In this process as said polyurethane foam sheet 11 with continuous foam, the sheet having the porocity about equal to 80cc/cm<2>/sec or more and the cell number about equal to 50/25mm or less, is used. This polyurethane foam sheet has the excellent porocity relatively to the sheet having been used up to now, and the foam size larger than that of a conventional sheet by about three times. Accordingly, because the foamed gas is exhaused from the mold, while causing said gas to flow through the total polyurethane foam sheet smoothly, the occurrence of the voids due to accumulated gas is surely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement in the method of manufacturing molded bodies of urethane foam.

[Technical foreground of invention]

0 as a manufacturing method for urethane foam, which is widely used as a seat for imperial tanks or as a seal for furniture.
Conventionally, a method has been used in which polyurethane foam sheets covering conventional foam are integrally molded and corrugated.

For example, as shown in FIG. 1(A), a lower mold 1 and an upper mold 2
When manufacturing an automobile cushion body using a mold having a molding chamber of a desired shape, a polyurethane foam seam for controlling air bubbles is applied to the molding surface of the upper mold 2. :
Covering is applied and 91 foam molding is performed, in this case,
! When the urethane foam stock solution 23 is sprayed and injected into the R-shaped chamber, the mold is closed, and foaming occurs. !
! Gas pigeon! ! ! Gas vent 3 hole 3 provided in 2...
- The liquid 12 escapes from the mold, expands in the urethane foam by foaming, and fills the inside of the molding chamber. At that time, the ridged urethane foam original jl! 12 is a polyurethane foam sheet) After coming into contact with 11, the bubbles are impregnated to form the polyurethane foam sheet shown in FIG.
An impregnated layer 11' is formed as shown in B). Note that the impregnated layer 11' is usually formed over the entire thickness of the polyurethane foam sheet 11, and the above manufacturing method has the following advantages.

First, in normal molding that does not use the polyurethane foam sheet 11, the foaming stock solution 12 is ejected from the gas vent S holes 3 along with the foaming gas, forming so-called "balls" on the upper mold 2, and However, there is a problem that some parts of the molded body are lacking in thickness.

In the method shown in FIG. 1, the foaming stock solution is impregnated inside the polyurethane foam sheet 11 and is prevented from blowing out, so that such a problem does not occur.

Therefore, the repair process after demolding is largely omitted, and productivity is significantly improved.

Secondly, the impregnated layer 11' loses its 91 strength and hardens because the bubbles are filled with the urethane foam stock solution. Therefore, as shown in FIG. 2, the produced cushion body has a hardened layer 1 impregnated on the back side of the 7# urethane mold 13. Equipped with '.

In this impregnated layer 11', polyurethane foam sheet) 12
Since the foam that was present in the foam is filled with the urethane foam stock solution, it loses its strength by 91% and hardens by 17%. A body having such a structure has the advantage that, compared to a body made of only the urethane foam layer 13, the feeling of bottoming out is eliminated and a good feeling of use can be obtained.

[Problems with background technology]

Although the conventional manufacturing method explained in FIG. 1 has the above-mentioned excellent features, it also has the following problems of the first order.

That is, even in the conventional manufacturing method, the polyurethane foam sheet 11 has an air permeability of 30 to 60 cc/am.
” / sec, Cell & J10 #150gl725
Although relatively breathable materials such as am were used,
Even so, the out-of-mold dissipation of foaming gas is inevitably reduced.
For this reason, problems such as the formation of cavities due to gas pockets have occurred when manufacturing seven-fold molded bodies having particularly complicated shapes.

In addition, for example, in the case of shoes 91 for self-help vehicles near Ik, there is a tendency to use thin urethane 7mm calendars 13 with a thin width. For this reason, it is difficult to obtain steamed man 2 using conventional manufacturing methods.
In the structure shown in the figure, the impregnated and hardened layer 11' becomes too hard, giving a rough and strange feeling to the surface, and there is a problem in that a comfortable feeling of use cannot be obtained.

[Purpose of the invention]

The present invention has been made in view of the above circumstances.

Mold gas release! Cover the molded surface with holes drilled.
A porous sheet such as a polyurethane foam sheet having i%ffi is installed to prevent the blowout of the foaming stock solution and to ensure good release of foaming gas when molding the urethane foam together with the porous sheet. The object of the present invention is to provide a method for producing a urethane foam molded article that can be maintained for a long time and avoid excessive curing of an impregnated layer.

[A purchase of invention]

The method for producing a urethane foam molded article according to the present invention is to cover the molding surface of the mold with the gas vent holes formed therein! In a method of installing a polyurethane foam sheet having air-regulating cells to prevent spouting of the 5-foam M liquid and molding the urethane foam integrally with the porous sheet,
#2 A polyurethane foam sheet having air bubbles with an air permeability of approximately 80 cc/cm2/s@e or more and a cell count of approximately 50 cells/25 cm or less*. The rapid-cell polyurethane foam sheet used in the invention has better air permeability than those conventionally used, and the size of the bubbles is approximately three times larger. Therefore, the foaming gas covers the entire polyurethane foam sheet. Since it flows smoothly and is discharged outside the mold, it is possible to reliably prevent the formation of cavities due to gas accumulation.

Also, because the cell diameter of the polyurethane foam sheet is large, 6 shots? ! 5. The stock solution easily penetrates into the cells and foams therein without being hindered by the cells. As a result, the impregnated layer has a dense foam structure, but the bubbles do not completely disappear, and the layer has a certain degree of elasticity. 1
2.1 In the case of the Kufun block similar to the man figure 2 produced by the method of the present invention, the impregnated layer 11' has appropriate elasticity, so it does not become stiff like the conventional one and can be made with thin glue. , it is possible to obtain a comfortable feeling of use even when the body is closed.

*When carrying out the manufacturing method of the invention, the amount of foaming stock solution to be injected is JR1! In this case, instead of forming the impregnated hardened layer 11' over the entire thickness of the polyurethane foam sheet 11 as shown in Fig. 2, @Fig. 3 (A) (B,
), it is possible to form a partially impregnated hardened layer 11' only on the surface of the urethane foam layer 13. As a result, it is possible to obtain a cushion body in which the elasticity due to the non-impregnated path acts and the feel from the surface is further improved. In this case, it is desirable that the thickness of the impregnated layer 11' be approximately 1/IQ to 7/1G of the thickness of the polyurethane foam sheet.

[Embodiments of the invention]

An embodiment of the present invention will be described below.

Example ether polyol water
3,5//triethylenediamine
0,17/Normal morpholine 0.8
〃Diptyltin dilaurate 0.1 nitricone oil 1,07/tolylene diincyanate 45〃 The production of polyurethane foam consisting of the following formula? a
An automobile cushion body was manufactured using the stock solution in the following manner.

That is, the automobile cushion gold fit explained in FIG.
2, and the molding surface of the upper mold 2 has an air permeability of 100cc/cm.
” / sec, 35 cells/25 m 5 soft polyurethane foam sheets with retro-air circulation @ 8 cm thick
Next, the above-mentioned polyurethane foaming stock solution was poured into the lower mold 1, and the upper mold 2 was closed.
& foamed. The amount of injection of the stock solution per shot was set to m so that the entire thickness of the polyurethane foam sheet was impregnated.

In the cushion body manufactured in this way, not only the integrally molded polyurethane 7T-filtrate is vaguely hardened, but also the cushion body has a moderate elasticity because it is made of foamed 4I structure. It was equipped.

[Brief explanation of drawings]

FIG. 1(^)(B) is a cross-sectional view for explaining a method of manufacturing a molded product of urethane foam that integrates a polyurethane 7t-me sheet. Figures 2 and 3 (A) are cross-sectional views showing *a of the 7-ohm urethane mold manufactured by the method shown in Figures 1 (A) and CB), respectively, and Figure 3 (B) is a cross-sectional view of the shape ( FIG. 3 is an enlarged cross-sectional view of a part of FIG. l...Lower mold, 2...Upper mold, 3...Gas vent hole, 1
1...Polyurethane foam sheet with open cells. 11'... Impregnated layer, 12... Foaming stock solution, 13...
Urethane Foam Mold Calendar Applicant Representative Patent Attorney Takehiko Suzue Figure 1 (A) (IB) Figure 2

Claims (1)

[Claims] A method in which a polyurethane foam sheet having open cells is installed to cover a molding surface with gas vent holes of a mold mold, and the urethane foam is integrally molded with the porous sheet while preventing the foaming solution from spouting out. The polyurethane foam sheet having open cells has an air permeability of approximately 80 cc/cm^2/sec or more and a cell count of approximately 5.
A method for producing a urethane foam molded article, characterized in that 0 pieces/25 mm or less are used.