JP3100188B2 - Manufacturing method of molded molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a molded molded article, and more particularly to a molded article for automobiles and furniture.
The present invention relates to a method for manufacturing a molded product.

[0002]

2. Description of the Related Art Conventionally, polyurethane foams having excellent elasticity, heat retaining property and light weight have been used as cushions for automobiles and furniture. It was manufactured by injecting a stock solution and foam molding.

[0003] By the way, such a urethane foam as a cushion is usually assembled by applying a spring or a frame to the back surface thereof. However, the urethane foam and the spring or the frame are used during vibration or seating during use. Scratches often cause abnormal noise. This is because the skin formed on the surface of the urethane foam and the urethane foam itself have a large frictional resistance.

[0004] For this reason, in order to prevent abnormal noise, a coarse felt or a non-woven fabric is attached to an upper mold or a middle mold and foamed integrally. FIG. 3 shows an example of a molded molded product obtained by such a method, wherein 1 is a pad (cushion main body), 2 is a felt integrally formed on the back surface of the cushion main body 1, 3 is a spring, and 4 is a spring. Frame
Show the system.

[0005]

However, according to the above-mentioned prior art, since the foaming pressure is high and the undiluted solution infiltrates to the back surface as shown in FIG. 4, abnormal noise cannot be completely prevented. For this reason, as shown in FIG. 5, the coarse felt 5 is glued by post-processing at the position where it comes into contact with the frame, but this reduces the workability.

The present invention has been made in view of the above circumstances, and provides a three-layer nonwoven fabric having a suitable thermoplastic resin nonwoven sheet interposed between predetermined first and second long-fiber nonwoven sheets. By attaching it to the upper mold in the case of a two-piece mold type, to the middle mold in the case of a three-piece mold type, injecting and foaming a polyurethane foam stock solution to form an integral mold,
It is an object of the present invention to provide a method of manufacturing a molded molded article capable of significantly reducing abnormal noise caused by rubbing of a cushion, such as a steel material such as a spring, a frame, or a pipe.

[0007]

According to the present invention, a basis weight of 80 to 80 is provided.
160 g / m ² A first and a second long-fiber non-woven fabric sheet made of a thermoplastic resin having a thickness of 1.0 to 3.0 mm;
.Placed between the second long-fiber nonwoven sheets, the basis weight is 30 to 6
0 g / m ² A three-layer non-woven fabric made of a thermoplastic resin non-woven fabric sheet having a thickness of 0.1 to 1.0 mm, and an upper mold in the case of a two-piece mold type, and a three-piece mold. In the case of a mold, this is a method for producing a molded molded product, which comprises injecting an undiluted polyurethane foam solution after attaching to a middle mold, closing the molded mold, foaming the molded product, and integrally molding the molded product.

In the present invention, the basis weight and thickness of the long-fiber nonwoven fabric sheet are limited as described above as follows. The long-fiber nonwoven fabric sheet in the above range has sufficient air permeability, has flexibility, and easily fits into a shape when attached to a mold. Further, when the urethane stock solution is impregnated and cured, the feel of the back surface of the product does not become too hard.

There is also a relationship between the basis weight and the thickness, but below this range, the urethane stock solution is often impregnated, and the feel of the back surface of the product becomes extremely hard. In addition, since the urethane undiluted solution partially seeps into the back surface, the original purpose cannot be achieved. Furthermore,
Above, not only the over quality but also the weight becomes heavy.

In the present invention, the nonwoven fabric having a three-layer structure includes a first and a second long-fiber nonwoven fabric sheet and a thermoplastic resin nonwoven fabric sheet.
By heating and compressing the sheet for a short time (1-2 seconds), the thickness can be adhered with almost no change. Further, the thickness can be reduced by heating and compressing for a short time. In this way, the thickness can be adjusted by temperature and time,
It is better to stop within 50% of the original thickness.

In the present invention, examples of the thermoplastic resin constituting the nonwoven fabric sheet include vinyl resins such as polyethylene, polystyrene and polyvinyl chloride, and chain polymer celluloids such as polyamide.

In the present invention, the thermoplastic nonwoven sheet is limited as described above as follows. In other words, the air permeability is moderately controlled by this, and the exudation of the urethane stock solution is suppressed. If it is less than 0.1 mm, it will seep out to the back surface. If the thickness exceeds 1.0 mm, the escape of bubble gas becomes poor, and the molded product often suffers from defects such as cracks and air pockets.

[0013]

According to the present invention, a non-woven fabric having a three-layer structure in which an appropriate thermoplastic resin non-woven fabric sheet is interposed between predetermined first and second long-fiber non-woven fabric sheets is used for foaming. The generated gas escapes smoothly from the nonwoven fabric, the foaming pressure is considerably reduced as compared with the conventional one, and it is possible to prevent the undiluted foam solution from seeping into the surface of the nonwoven fabric. Therefore, even when the cushion body comes into contact with a steel material such as a frame or a spring during use of the molded molded product, it is possible to prevent generation of abnormal noise.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a sectional view of a molded molded product, and FIG. 2 is a partially enlarged view of FIG.

Reference numeral 11 in the drawing denotes a cushion body made of, for example, urethane foam. On the back surface of the cushion body 11, a three-layer nonwoven fabric 12 is formed integrally with the cushion body 11. Here, as shown in an enlarged manner in FIG. 2, the nonwoven fabric 12 has a basis weight of 120 g / m ^2. , Thickness 2mm
The first and second long-fiber non-woven fabric sheets 13a and 13b made of the above-mentioned thermoplastic resin, and the weight per unit area of 40 g / m ² disposed between these long-fiber non-woven fabric sheets , A thermoplastic resin non-woven fabric sheet 14 having a thickness of 0.35 mm. In the drawing, reference numeral 15 denotes a spring, and 16 denotes a frame. A molded molded body having such a configuration is manufactured as follows using, for example, a two-piece molded mold.

(1) First, 3 to be attached to the inner surface of the upper mold beforehand
A nonwoven fabric 12 having a layer structure is prepared. This nonwoven fabric has a basis weight of 120 g / m ^2. The weight between the first and second long-fiber nonwoven fabric sheets 13a and 13b made of a thermoplastic resin having a thickness of 2 mm is 40 g / m ^2. , Obtained by heating and compressing a thermoplastic resin nonwoven fabric sheet 14 having a thickness of 0.35 mm for about 1 to 2 seconds.

(2) Next, the nonwoven fabric 12 is attached to the inner surface of the upper mold, and the frame 16, the spring 15 and the like are set. Subsequently, after injecting the polyurethane foam stock solution into the lower mold, the mold is closed. Further, foaming was performed in this state to produce a molded molded product in which the nonwoven fabric 12 was integrally formed on the back surface of the cushion body 11, and the frame 16 and the spring 15 were integrated.

According to the method for manufacturing a molded molded article according to the above embodiment, since the nonwoven fabric 12 having a three-layer structure is attached to the inner surface of the upper mold and foamed, the gas generated during foaming is generated by the nonwoven fabric. Exit from 12 smoothly. Therefore, the foaming pressure is considerably reduced as compared with the conventional one, and the foaming stock solution becomes nonwoven fabric 12.
At the middle of the thermoplastic resin nonwoven sheet 14 without leaching on the surface (the surface of the second long-fiber nonwoven sheet 13b). Therefore, even when the cushion body 11 comes into contact with the frame 16 or the spring 15 during use of the molded molded product, it is possible to prevent the generation of abnormal noise. Further, the weight is light, and post-processing such as attaching a felt as in the conventional improved example is not required, so that the number of steps can be reduced.

[0019]

According to the method of the present invention as described in detail above,
A three-layer nonwoven fabric having an appropriate thermoplastic resin nonwoven fabric sheet interposed between predetermined first and second long-fiber nonwoven fabric sheets;
In the case of a two-part mold type, the upper part is used, and a three-part mold is used.
In the case of the mold type, after installing it in the middle size, the polyurethane foam stock solution is injected, foamed and integrally molded to completely reduce the noise caused by the rubbing between the cushion, the steel material such as springs, frames and pipes. Thus, a molded molded product having a lighter weight and capable of reducing the number of steps can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molded molded product according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a cross-sectional view of a conventional molded product.

FIG. 4 is an explanatory diagram of a conventional problem.

FIG. 5 is an explanatory view related to improvement of a conventional molded product.

[Explanation of symbols]

11: cushion body, 12: non-woven fabric, 13a, 13b ...
Long fiber non-woven fabric sheet, 14 ... thermoplastic resin non-woven fabric sheet
G, 15 ... spring, 16 ... frame.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI B29K 105: 08 B29L 31:58 (58) Investigated field (Int.Cl. ⁷ , DB name) B29C 39/10-39/12 B29C 39/22-39/24 B32B 5 / 26,27 / 12

Claims (1)

(57) [Claims] 1. Weight per unit area of 80 to 160 g / m ² , Thickness 1.
First and second long-fiber non-woven fabric sheets made of a thermoplastic resin having a thickness of 0 to 3.0 mm, and a weight per unit area of 30 to 60 g / m ² disposed between the first and second long-fiber non-woven fabric sheets. , Thickness 0.1 ~
After attaching a nonwoven fabric of a three-layer structure composed of a 1.0 mm thermoplastic resin nonwoven fabric to an upper mold in the case of a two-piece mold type, to a middle size in the case of a three-piece mold type, A method for producing a molded molded product, comprising: injecting a polyurethane foam stock solution, closing the molded mold, foaming the molded product, and integrally molding the molded product.