JPH01180332A - Cushion material - Google Patents

Abstract

PURPOSE:To obtain a cushion material which causes less partial sinking when a man sits thereon, with having superior surface rigidity, shock absorbing property and cushioning property, by embedding into a soft foaming member a bulky net of synthetic resin which is rigid and flexible with uneven surface. CONSTITUTION:A cushion material is of such construction that a bulky net 2 made of such synthetic resin as polyethylene or polypropylene that is both rigid and flexible, with having uneven surface, is embedded in a soft foaming member 7. When the bulky uneven net 2 is set in molds 1, 4, and for example, a stock solution compounded for soft-foaming polyurethane is injected into the molds, the solution passes through meshes of the net set in the molds to foam and harden the foaming member. Therefore, concurrently with the foaming process, the net can be integrally united completely with the foaming member thereby to obtain a cushion material. The rigidity of the net which is integrally foamed with the foaming member in a solid structure can prevent a sudden sinking of the cushion. On the other hand, the flexibility of the net itself can absorb shocks. Thus, the cushion material is provided with adequate shock absorbing and cushioning properties.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a foam cushioning material used for automobile seats, various indoor chairs, bedding mats, and the like.

[Conventional technology]

Conventionally, soft urethane foams have been widely used as cushioning materials for automobile seats, various chairs, bedding, etc. because of their soft feel and excellent cushioning effect.

[Problems to be solved by the invention] ゛However, the soft polyurethane foam has low surface rigidity and locally sinks significantly in areas where a load is applied, resulting in poor body fit. The problem is that it does not provide a pleasant sensation, and various improvement measures are being considered. For example, fiber padding materials made by mixing natural fibers such as coconut fibers and pig hair and hardening them with latex have been developed as cushioning materials for automobile seats, and are already in practical use in some areas. Compared to conventional soft urethane foam, this fiber type has superior surface rigidity, better vibration characteristics, and is extremely comfortable to sit on, but it is also expensive, heavy, and flame resistant. It has disadvantages such as poor properties and durability.

In addition, Japanese Patent Application Laid-open No. 184816/1983 discloses a cushion body for automobile seats that increases the stability of the body when sitting, provides a good fit to the body, eliminates discomfort, and improves sitting comfort. discloses a method of forming a highly hard urethane foam layer on a portion of a soft urethane foam.

However, the seat cushion body manufactured by the method of JP-A No. 62-184816 has a highly hard urethane foam layer formed only on the portion corresponding to the peripheral side wall of the automobile seat cushion body, and the seat cushion body is formed with a conventional soft urethane foam layer. Since it is still made of urethane foam, the surface rigidity of the seating portion remains unchanged and has not been improved, and the problem of local sinking when seating still remains. In addition, the manufacturing method requires two foaming operations: first, a highly hard urethane foam layer is formed on the peripheral side walls of the seat cushion body, and then a soft urethane foam layer is formed on the portion corresponding to the seating area. However, the problem is that productivity is low.

Furthermore, in JP-A-52-15765, a hard plate such as an iron plate or a synthetic resin plate with many protrusions formed on one side is used as a medium for a soft cushion body such as a soft urethane foam.
By embedding the M hard plate with protrusions protruding on the surface that comes into contact with the human body, or by bonding a soft cushion body to the surface from which the protrusions of the hard plate protrude.
The protrusions of the hard plate receive the load of the person sitting on the seat, preventing the cushion body from sinking locally, and the protrusions press against a part of the human body to stabilize the sitting posture and provide a good feel. A cushioning material is disclosed that is effective in preventing fatigue. However, it cannot be denied that the cushioning material disclosed in JP-A No. 52-15765 is inferior in cushioning material and cushioning properties compared to conventional soft cushioning materials because the projections of the hard plate press against the human body. Furthermore, it is impossible to form the position and shape of the protrusion so as to provide an appropriate pressure (acupressure) effect depending on the person sitting, and depending on the weight and body shape of the person sitting, the hard protrusion may be The problem is that it causes discomfort.

The present invention aims to solve the above-mentioned problems and provide a new cushioning material that has excellent surface rigidity and good cushioning properties and cushioning properties.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the inventors of the present invention embedded a bulky synthetic resin net with irregularities that is both rigid and flexible into the conventional soft foam. The present inventors have discovered that, by doing so, it is possible to obtain a cushioning material that has excellent surface rigidity, excellent shock absorbing properties, and cushioning properties, and is less likely to sink locally when seated.

That is, the present invention is a cushioning material having a structure in which a bulky net with irregularities made of a rigid yet flexible synthetic resin such as polyethylene or polypropylene is embedded in a soft foam.

In addition to the polyethylene and polypropylene mentioned above, thermoplastic synthetic resins such as polyvinyl chloride and polystyrene AB8 are preferred as materials for the bulky net used in the present invention.

In addition, as a method for manufacturing a bulky synthetic resin net with uneven surfaces, a general extrusion process using an annular die can be used, for example, by rotating the inner dies of the annular die in opposite directions. First, a cylindrical net is formed by extruding the molten resin through a number of small holes provided on the circumference along the boundary between the gou and the outer die, and then the net is cut open to make a flat net. , a flat net of thermoplastic resin with appropriate rigidity and flexibility is formed, and after this net is heated, a male material having many convex portions and a large number of concave portions corresponding to the convex portions are formed. A method of forming irregularities on a flat net to make a bulky net by press-forming with a female star having a holder, or heating the flat net and then forming the net with a pair of molds in which a large number of bottles are arranged alternately. The height and shape of the unevenness can be set by the shape of a press-formed Venus or the shape of pins provided on a pair of forming plates. It is preferable to determine the height and shape depending on the intended use of the cushioning material.

To manufacture the cushioning material of the present invention, first, a bulky net with irregularities is set in a mold as shown in Figure 1, and then, for example, a stock solution prepared for soft polyurethane foaming is injected, foamed, and hardened. This can be easily done by doing this. In other words, the foaming progresses and hardens by passing through the mesh gaps of the net set indoors, so that the integration with the net is completed at the same time as the foaming process, and the desired cushion material as shown in Figure 2 is obtained. .

[Effect]

The cushioning material according to the present invention has a soft foam penetrating a bulky net with irregularities that has appropriate rigidity and flexibility, and has rigidity and flexibility inside the conventional soft foam. Since the net has a three-dimensionally integrated structure, it retains the cushioning properties and soft feel of conventional soft foam, and has excellent surface rigidity.

That is, the rigidity of the three-dimensionally integrated net prevents the soft material from sinking rapidly, while the flexibility of the net itself absorbs impact and provides appropriate cushioning and cushioning properties.

〔Example〕

The present invention will be explained below using examples.

Example 1 A commercially available polyethylene resin net (trade name, Trical Net N-598) was used to fit male Venus, which has many cylindrical convex parts with a height of 40 mm and a diameter of 30 m at regular intervals, and its convex parts. Using a press molding machine consisting of a female Venus with a concave part, it was heated and pressed to form a bulky net with concavities and convexities of 40 wg in height, and the net was set in a polyurethane foam molding shop with a depth of 601 m. A predetermined amount of polyurethane foam stock solution (Nisshinbo Co., Ltd. (trade name, Air Light Foam, 5K-1) was injected and closed, followed by foaming and curing to obtain a cushioning material of the present invention having a thickness of 60 wgm.

In addition, for comparison, only the soft polyurethane foam stock solution used above was injected into the same 60 m deep mold to obtain a soft polyurethane foam cushioning material with a thickness of 60 mrx made only of polyurethane foam (Comparative Example 1). .

Example 2 A commercially available polyethylene resin net (trade name: Yucalon Net, U-30) was heated to a temperature above its softening point, and a diameter of 12 wt.
φ, height 500 pins are placed between a pair of molds equipped with a number of pins at regular intervals, and a heated net is pressed from both pages so that the opposing pins interlock with each other to create unevenness of 200 mm height. This net-like body was made into a bulky net-like body, and the net-like body was set in a polyurethane foaming mold with a depth of 50 mm, and a predetermined amount of the same polyurethane foaming stock solution as in Example 1 was injected, and after closing, the foaming,
After curing, a cushioning material of the present invention having a thickness of 50 mm was obtained.

For comparison, only the same polyurethane foaming solution as above was injected into the same mold with a depth of 50 m, and after closed plasticization, foaming,
After curing, a soft polyurethane foam cushioning material having a thickness of 50n+ was obtained (Comparative Example 2).

In addition, Examples 1 and 2 and Comparative Examples 1 and 2 were compressed with a weight of 50 m x 50 m size, and the results of measuring the compressive stress are shown in Table -■
Shown below.

Table - ■ Compressive stress measurement results (effects of the invention) The cushioning material of the present invention has excellent surface rigidity, moderate cushioning properties, and cushioning properties, and when sitting, the area where the load is applied is localized. The seat does not sink too much into the seat, provides a good fit to the body, and stabilizes the posture when seated.
Provides good seating comfort.

In addition, the conventional molding process for soft foam cushion bodies can be used as is, and by changing the material and shape of the net, surface rigidity, cushioning properties, shock absorbing properties, etc. can be changed, depending on the application. Various cushioning materials can be manufactured easily and at low cost.

[Brief explanation of the drawing]

Figure 1 shows a method of setting a bulky net with unevenness inside the mold.1. ? FIG. 2 shows an example of a cross-sectional view of the cushioning material of the present invention. 1 is a mold (shelf), 2 is a bulky net, 3 is a pin for fixing the net of the mold, 4 is a mold (lower mold), 5 is a foam spacer, 6 is a frame for fixing the net, 7 is a soft It is polyurethane foam. Patented wheat flour Asahi Kasei Industries Co., Ltd. Figure 2

Claims (1)

[Claims] A cushioning material made of a bulky, uneven synthetic resin net and soft foam.