JPH0464383B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Purpose of the Invention At present, sponges with cushioning properties are used in large quantities in automobiles, furniture, bedding, hardwear, footwear, and the like.

During the manufacturing process and after use,
A large amount of leather, cutting waste, mold foam waste, bulky waste, etc. are generated, but only a portion is used, and the majority is incinerated or landfilled as industrial waste.

The present invention is a tatami floor made from a mixed recycled sponge made by mixing open-cell foam sponge waste with air permeability and cushioning properties, which is currently unused, and closed-cell foam waste with non-breathable cushioning properties. This makes it possible to supply lightweight, cheap, and durable tatami mats, and contributes to improving the living environment of humankind in the future.

Structure of the Invention A Contents of the Structure Sponges with cushioning properties generally increase in hardness in proportion to density. However, if a non-breathable material (closed-cell foam) and a breathable material (open-cell foam) are made of the same material and have the same density at room temperature, the elasticity of the open-cell foam is approximately 1 more than that of the closed-cell foam. /10 and soft. (Plastic Foam Handbook P227, Fig. 111, 5S48) When the temperature rises, closed-cell foam sponges with cushioning properties not only become softer due to the synthetic resin they are made of, but also the gas inside the closed-cell foam expands. Its coefficient of linear expansion is approximately 10 times greater than that of open cell foam. (Plastic Foam Handbook P645-653) When converted to area, it is approximately 100 times larger.Therefore, no matter how excellent the closed-cell plastic cushion material is, it is difficult to use as a tatami floor that is spread over a limited area. It cannot absorb the thermal expansion of the material and cannot be used alone as a tatami floor.

When used, due to the thermal expansion of the gas within the closed cells due to temperature rise, the cushioning properties of the foam will rise or deform. Currently, polystyrene foam pasted on plywood boards and polyethylene foam sewn into straw tatami mats in the form of a sandwich are used as closed-cell foam for tatami mat flooring. (Asahi Kasei Styro Tatami) To achieve the hardness of a tatami floor using only open-cell foam, the density must be compressed to 0.5 to 0.6. (See Figure 2) This is about twice as heavy as rice straw, which has a density of 0.2 to 0.4 (Heibonsha Encyclopedia).

The present invention combines the best features of both, by using air permeable open cell foam waste that can withstand temperature changes as the main material, and scattering non-permeable, light and highly elastic closed cell foam waste therein. This tatami floor has cushioning properties similar to straw tatami flooring. This material is called mixed recycled sponge for tatami mats. This product is manufactured as follows.

As shown in Figure 2, the proportions of the ingredients in the raw materials vary considerably, but in general,
Grind each part of closed cell foam waste to 10 mm or less and apply adhesive while mixing to reduce the density.
It can be made by compressing, molding, and heating drying to a size of 0.2 to 0.3. In its current state, it looks like wood with some elasticity. However, if you slice it into pieces of about 10mm, you'll get a smooth, hard, konnyaku-like plate. It feels just like a sea cucumber, making it easy to bend and difficult to hold. Thickness 0.5 on both sides of this item
When a ~1mm thick reinforcing material (waterproof paper) is pasted, the whole thing becomes stiff and becomes like a fusuma fusuma. This is easy to carry and can be easily processed into tatami mats. The feel is also similar to the tatami floor and structure made of rice straw. The reinforcement material replaces the strength of the rice stalks in the straw tatami floor. Water-resistant paperboard is cheap and easy to process.

For an elegant and durable finish, use a durable plain weave cloth. If water resistance is your priority, plastic film is a good choice.

(b) Functions of Components When you press a slice of this mixed recycled sponge for tatami mats into about 10 mm pieces with your fingertips, you will feel that the hard and soft parts feel rough to your fingertips. However, when a reinforcing material is applied, the tension of the reinforcing material equalizes the pressure, and the feel becomes very weak. Furthermore, if you put a tatami cover on top of it, you can barely tell. Why does a mixed recycled sponge that is about 10mm thick feel like a 50mm rice straw tatami floor?It is soft and hard. Upon analysis, it was found that first the open cell foam debris was trapped by the weak vertical pressure, and then the closed cell foam debris was trapped and further force was applied until it became unbearable.
It begins to crawl into weak spots in the horizontal direction, and eventually, due to the elasticity of the materials such as soft polyurethane rubber, natural rubber, polyethylene, and vinyl acetate resin, the mixed recycled sponge for tatami mats becomes a fraction of the size of rice straw tatami flooring. I think it has a similar cushioning effect depending on its thickness.

Rice straw itself is mainly composed of cellulose, which itself has poor elasticity. However, the dehydrated cells of the stem form a closed cell foam. In addition, the overlapping state of rice straw forms an open cell foam. This is also a mixture of open and closed cell foams. Therefore, by making the straw thicker, air is trapped between the straw, creating the cushioning properties of tatami. Unless an ordinary item is destroyed, the more it is compressed to increase its density, the harder it becomes.

The same goes for mixed recycled sponge for tatami mats.

According to Heibonsha's encyclopedia, the heavier the tatami floor, the higher the quality, ranging from 17 to 30 kg. It is said that the harder it is, the better. Density (0.2 - 0.36) In the case of mixed recycled sponge for tatami mats, if you try to make it the same hardness as a straw tatami by using only breathable open cell foam waste without adding closed cell foam, the density will increase as a result of an experiment. It will not become hard unless it is compressed to about 0.6 degrees. (See Figure 2) If it is just closed cell foam waste, about 0.15 is sufficient. In order to make mixed recycled sponge for tatami mats as hard as an average straw tatami floor, the compression density changes depending on the ratio of open cell foam and closed cell foam components. The results of the experiment are shown in Figure 2. The higher the proportion of open-cell foam, the higher the density and, in other words, the heavier it must be. The more closed cell foam there is, the lighter it can be. However, the larger the number of closed cells, the larger the temperature change, and the more difficult the manufacturing method.

As is clear from Figure 2, by adding 10 to 20% of closed cell foam waste, it is possible to achieve a density and weight that is approximately half that of open cell foam alone.

As a result of experiments, mixed recycled foam for tatami mats made with 4 parts of soft polyurethane foam waste and 1 part of EVA foam waste has a density of about 0.25, and it is easy to manufacture a uniform product. Temperature change (-10℃~50℃)
It can withstand high temperatures. The manufacturing process for mixed recycled sponge for tatami mats consists of crushing, measuring and mixing, applying adhesive, compression molding, heating, taking out, and attaching sliced reinforcing material.During compression molding, open cell foam waste is also separated from closed cell foam waste. is also compressed and the elasticity is balanced. However, when heated with heated steam, the closed cell foam debris expands. However, when it cools down, it becomes smaller and harder than before. The open cell foam debris is therefore less elastic than its equilibrium prior to heating.

As a result, the mixed recycled sponge is made of bonded materials of various sizes of less than 10 mm, including materials with weak elasticity and materials with strong elasticity. As a result, a material with a thin but wide cushion was created.

This product has good absorption of pressure and impact energy, and the mixed recycled sponge is less likely to be crushed or destroyed than a cushion material made of only closed cell foam or a cushion material made only of open cell foam, that is, a single substance.

Instead of soft polyurethane foam, soft latex foam is used as an open-cell foam cushion material, and a closed-cell foam cushion material is used instead of soft polyurethane foam.
Natural rubber sponge, polyethylene foam, etc. may be used instead of EVA foam. Natural rubber is somewhat heavier. The raw material for latex foam is old pine tresses, which are generated in large quantities as bulky waste at incineration plants.

Semi-rigid flexible polyurethane foams are made of both open-cell and closed-cell foams. Composite materials of open cell foam and closed cell foam, such as those made by bonding soft urethane foam to EVA foam, can also be used as raw materials.

C Example Soft polyurethane foam scrap 27.5K EVA foam scrap 7.0K Adhesive 2.5K37.0Kg Apply adhesive while spinning the above materials in a blender, compression mold and dry 1800×900×95mm……37Kg Tatami Make mixed recycled sponge buns.

It feels like elastic wood.

If you remove the skin from both sides (approximately 2 kg) and slice it into 7 equal pieces, you will end up with a board of 1800 x 900 x 12 mm...5 kg of mixed recycled sponge for tatami mats. This is a heavy, bendable, hard, konnyaku-like plate-like object. Thickness 0.5~ on both sides
If you paste a 1mm waterproof paperboard, a fusuma-like material will be created.

As for the hardness, just like rice straw tatami flooring, you can use a special sewing machine to sew the tatami face together with the edges. Turn it inside out, staple it, and put duct tape on top to create a tatami mat. The total weight is 7 kg, which is about 1/4 lighter than straw tatami. The feeling of walking on, sitting on, and lying down on is not much different from straw tatami.

Although it is thin at 15mm thick, its heat retention is not much different from a 50mm straw tatami mat.

D Conclusion The tatami floor made from rice straw is 50mm thick and weighs 17 to 30kg, and is mechanically and structurally strong, and the 14mm thick mixed recycled sponge tatami floor has better impact resistance. It's better. Even if the floorboards are a little bad, they can support the weight of a person, and the larger the mass, the more the impact force can be alleviated. In other respects such as cushioning properties, water resistance, lightness, heat retention, processability, etc., the mixed recycled sponge for tatami mats of the present invention is superior as a tatami floor.

The rice straw tatami floor and the sponge tatami floor of the present invention have similar cushioning properties because they have roughly the same density and are structurally similar to a mixture of closed cell foam and open cell foam. I think it's my fault.

Rice straw density 0.2 0.12Kcal/m, h, °C Polyurethane foam Density 0.2 0.025Kcal/m, h, °C (Plastic Foam Handbook P17 Figure 1.
5) For the above reasons, it may be thin.

Effects of the invention It is thin and lightweight, making it easy to store and carry.

Since cutting can be done using a hydraulic press, standard products can be mass-produced.

Water resistant.

There are no mites.

Very cheap compared to conventional products. (More than 30%) Because it is thin, it can be used in small spaces such as under hospital beds and in vehicles.

Unlike straw tatami floors, it doesn't produce any garbage, and it doesn't damage the floor surface like veneer or tatami floors do.
It can also be used in gymnasiums, hallways, western-style rooms, etc.

If you place a heavy object on it, it is less likely to get crushed because it is thin from the beginning.

For this reason, tatami can be sold as standard products, ready-made products, and sold in stores through distribution systems.

The main material is a mixed recycled sponge for tatami mats with cushioning properties, so when laying on a limited area, 0~
The tatami floor can be compressed vertically and horizontally by about 10mm, and it will not move even if the tatami floor is thin.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the present invention. 1... Reinforcement material, 2... Non-breathable sponge waste (closed cell foam), 3... Breathable sponge waste (open cell foam). Figure 2 is a graph of the relationship between the ratio of mixed components to maintain the hardness of the tatami floor and the compression density. %) The horizontal axis is the density of the tatami floor of the present invention

Claims (1)

[Claims] 1 Sponge waste composed of open-cell foam with cushioning properties and closed-cell foam with cushioning properties (open-cell foam and closed-cell foam mixed, separate, or bonded together to form a composite) (Anything allowed) is crushed to 10 mm or less,
The proportion of the closed cell foam component to the total is 5.
%~30% (The proportion of vertical open cell foam is 95%)
~70%), apply adhesive while rotating a blender, compress and mold to a density of 0.2 to 0.4, and then slice to create an independent, continuous, A tatami floor made by pasting reinforcing material on both sides of a recycled sponge board made from a foam mixture.