JPS639479A - Production of cushion body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a cushion body made of polyurethane foam.

[Conventional technology]

Polyurethane foam is shaped into the shape shown in Figure 3 and used for cushions for vehicles, and cushions for furniture!
It has been widely used as various cushion bodies, including as a cushion.

These polyurethane foam cushion bodies are manufactured by foam mold shaping, and for example, the cushion body shown in FIG. 3 is as follows. That is, using a mall type F, which consists of a lower mold 2 and an upper mold 3 shown in FIG. The mold is closed, the foam is cured, and then the mold is removed to obtain the desired cushion body.

[Problems that the invention seeks to solve]

In the conventional manufacturing method using foam mold shaping, the quality of the foaming reaction of the urethane foam stock solution directly influences the quality of the cushion body product, such as mold temperature, liquid temperature, injection amount, etc.
If other conditions are not met, defects such as cracks, missing parts, and cavities will occur.

In addition, products with irregularities or complicated shapes, such as the backs of automobile seats (front back butts), have thin walls and many irregularities, resulting in defects such as underfilling and cavities due to so-called gas accumulation.

If the above defects occur, the product must be repaired after mold shaping, which significantly impedes productivity.In addition, if the defect is severe, repair is impossible and the product must be discarded as a defective product. This results in a decrease in yield.

In view of the above circumstances, it is an object of the present invention to provide a method of manufacturing a polyurethane foam cushion body with high productivity without requiring any repair work after shaping.

[Means for solving problems]

The method for manufacturing a cushion body according to the present invention includes storing a polyurethane foam block of arbitrary thickness and arbitrary shape in a predetermined mold having a shaping chamber corresponding to the shape of the cushion body;
It is characterized by giving the polyurethane foam the shape of the shaping chamber by closing the lid, compressing the polyurethane foam along the internal shape of the shaping chamber, and heating it at a high temperature to cause permanent deformation. be.

The type of polyurethane foam used in the present invention is not particularly limited, but from an economical point of view, it has a density of 20
It is preferable to use one with a weight of less than kg/m3, especially,
A low density amount of 12 kg/m3 or less has good compression shaping properties.

It is preferable that the compression ratio in the present invention is at least 30%. If the compression ratio is lower than this, it may be restored little by little due to the influence of heat during use or after repeated use. be. The compression method is not particularly limited, and may be performed mechanically using a press, or may be performed manually.

The heating temperature in the present invention is preferably 120° C. or higher, particularly preferably 170° C. to 250° C. If the heating temperature is 120° C. or lower, long-term compression is required.

[Effect]

In the case of the present invention, the shaping performance is not influenced by the chemical reaction as in the case of conventional foam mold shaping, and therefore defects such as cracks, underfilling, cavities, and gas pockets do not occur. Since no repair process is required, productivity and yield can be improved.

In addition, in the case of conventional foam mold shaping, it is necessary to spray a large amount of a mold release agent made of a diluted solvent or an aqueous emulsion onto the inner surface of the mold, which poses many problems in terms of working environment hygiene. Since no mold release agent is required, such problems do not occur.

〔Example〕

Example 1 As shown in FIG. 1(A), a mold for an automobile front seat cushion butt (maximum height of the shaping room 35 mm) 1
A polyurethane foam block 21 having a density of 12 kg/m3° and a thickness of Loomm was placed inside the chamber. This is forcibly compressed to close the mold as shown in Figure 1 (B).
When the mold was removed by heating at 90° C. for 40 minutes, a front seat cushion bat shaped into the shape of the mold shaping chamber was obtained.

The cushion bat obtained above had a completely fixed shape and did not restore its shape even after being left alone. Furthermore, as a matter of course, no defects such as cracks or cavities were observed.

Example 2 As shown in FIG. 2(A), a mold for an automobile front seat back butt (maximum height of the shaping room: 35 mm)13.
14 with a density of 8 kg/m3. A polyurethane foam block 23 with a thickness of 100s+s was placed. This is the second
As shown in Figure CB), the mold is forcibly compressed and closed.
When the mold was removed by heating for 25 minutes at ℃, a front seat back bat shaped into the shape of the mold shaping chamber was obtained.

The cushion bat obtained above had a completely fixed shape and did not restore its shape even after being left alone. Furthermore, as a matter of course, no defects such as cracks or cavities were observed.

Although the above embodiments are all examples in which the invention is applied to the production of cushion bodies for automobile seats, the present invention can be applied to the production of any other cushion bodies.

〔Effect of the invention〕

As described in detail above, according to the present invention, there is no need for any repair processing after shaping when manufacturing a cushion body made of polyurethane foam, and high productivity can be obtained.
This has significant effects such as improving the sanitary environment of work.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to the manufacture of a front seat cushion bat for an automobile, and FIG. 2 is a sectional view showing another embodiment in which the present invention is applied to the manufacture of a front seat back bat for an automobile. The sectional view and FIG. 3 are perspective views showing an example of a cushion body made of polyurethane foam,
FIG. 4 is an explanatory diagram showing a foam mold shaping die used in the conventional manufacturing method. 11.12, 13.14... Mold, 21.23...
Polyurethane foam block, 22...Front seat cushion bat, 24...Front seat back bat Applicant's representative Patent attorney Takehiko Suzue (A) 1st (4th 2nd iN)

Claims (2)

[Claims] (1) A polyurethane foam block of arbitrary thickness and arbitrary shape is stored in a predetermined mold having a shaping chamber corresponding to the shape of the cushion body, the lid is closed, and the polyurethane foam is compressed along the internal shape of the shaping chamber. . A method for manufacturing a cushion body, characterized in that the polyurethane foam is given a shape of a shaping chamber by heating at high temperature to cause permanent deformation. (2) The compression rate of the polyurethane foam block is
The method for manufacturing a cushion body according to claim (1), wherein the ratio is 30% or more at the smallest portion.