Density of foam rubber. Types and purpose of foam rubber

For the production of furniture requires quality, soft and elastic filling. The material should support a spring block of a sofa or a bed, assist in the design of comfortable seat seats and ensure the filling of backrests and armrests. Professional furniture manufacturers have such an abbreviation as PPU. Many people have heard a name like polyurethane foam, and ordinary people know the word "foam rubber". In fact, these are different names for one material. It is the density of foam rubber that affects the scope of its use and the quality of the product.

Quality characteristics of polyurethane foam

The main mechanical properties of the PPU include the following characteristics:

• Density of foam rubber;
• rigidity;
• elasticity;
• Air permeability;
• Tensile strength;
• The size of the cells;
• Possibility of extension;
• Coefficient of support.

The size of the cells and the coefficient of support are considered on highly elastic samples.

From these characteristics depends not only the quality of the material, but also how much furniture will be durable and comfortable, as well as air permeability of the product.

Parameters of foam rubber quality. Density

Foam furniture is evaluated primarily by its density. This parameter depends on the service life. The higher the density, the longer it can be used without disturbances in quality characteristics.

This fact is explained by the fact that the foam rubber is subjected to heavy loads, and the brand with the greatest density is better able to withstand dynamic and static weighting. To understand the mechanism of action, it is necessary to represent the number of polyurethane foam per unit volume. It is clear, in a place where it is more, not so soon there will be dents and attritions.

Do not confuse the density of foam with an indicator of its rigidity. These concepts are interrelated, but not identical. There are grades of PPU with low density and high rigidity.

Scope of application

Polyurethane foam is quite common and is used in various fields of production:

• Furniture;
• Construction (sound and heat insulation);
• Sports (mats, boxing pears);
• Medical (orthopedic goods);
• Sewing soft toys and clothes.

Foam differs depending on the purpose of the quality and price category. Durability, density, rigidity and elasticity depend on the composition.

Advantages of polyurethane foam

The material is very popular in various spheres of production because of its weighty merits. So, it has high wear resistance. In addition, it is completely hypoallergenic, so it is absolutely safe to produce not only furniture, but also children's goods, orthopedic products.

Foam is moisture-resistant, so it is not susceptible to the formation of harmful microorganisms in it. At the same time, it completely preserves the qualitative characteristics for a fairly wide temperature range (from -40 to 100 degrees).

Due to good acoustic insulation, foam is successfully used as an insulating material. And elasticity allows to use it in creating products of any size and shape.

With its advantages, the PPU can withstand a rather long period of active operation. Depending on its density and purpose - from 5 to 15 years.

Foam marks

In furniture production a different PPU is used, which is divided into specific brands.

Brand ST. It is considered a standard material, from the characteristics of which other types are counted. It is used mainly for stuffing armrests or seat chairs.

Brand of increased rigidity EL. This is a modified standard material with more rigidity. This density of foam rubber for the sofa is most suitable, because it can withstand static and dynamic loads. In addition, this brand is used in the manufacture of hard mattresses.

The brand is highly elastic (HR) . The most comfortable material, which combines elastic properties and a fairly low initial rigidity. Due to this property the material is used in the manufacture of quality furniture and for filling seats. So, it is the brand HR - the ideal density of foam rubber for chairs and orthopedic mattresses.

Choices

In the production of foam rubber, the main emphasis is on the thickness and density. From these indicators depends on what needs he can go.

So, high-density foam is used in making sofa seats, because softness is good, but at the same time a person will simply fall through. Also, dense material is important in the manufacture of mattresses, because a firm and level surface for sleep is preferable for many.

At the same time, the sofa does not consist of one sitting space. It is necessary to equip armrests, frame, side walls, etc. They, too, need a soft arrangement, depending on the purpose they select the brand of foam rubber.

For seats choose elastic and rigid foam. The thickness of the foam is not important, because comfort and convenience are not provided by one layer. To achieve the best effect, several sheets of material are used. At the same time for the production of any kind of furniture use different brands of foam rubber.

Special Purpose Foam

If foam rubber (density 40) is often used in the production of furniture, the less dense is used in many other areas. So, sanitary and hygienic needs (kitchen and bath sponges) require a material that will not crumble, will foam well and withstand frequent contact with water. For this, special additives are used that improve the quality characteristics and at the same time do not cause allergies.

There are viscoelastic brands that have found their application in the production of medical products. Widely used in the manufacture of linings used for burns. The material takes the contours of the body and less injures the affected area.

Contour products, such as rollers, cylinders, rods, are made from block foamed polyurethane. It is completely homogeneous and quite elastic.

The main points of care for a foam rubber product

To maintain the consumer properties of PPU and extend its service life, it is worth applying a few simple rules:

• Remove dust with a vacuum cleaner, without using mechanical means;
• Do not use detergents that contain alcohol that destroys the fibers of the material;
• Do not expose to too high temperatures, in particular, do not iron with iron.

These simple rules will maintain the foam density in the proper quality, respectively, the deformation of the product will not occur.

Foam for a mattress

In the production of bed beds use foam rubber furniture. What density is needed for the mattress, depends on the alleged rigidity of the product.

The standard grade PPU is used for making children's mattresses. Its density is 25 kg / m ³ .

For elite beds and longer exploitation, latex foam is used, which is labeled HR and VE.

The brand of increased rigidity EL can withstand loads up to 100 kg. View EL2240 is a budget option that is suitable for infrequent use or for a lifespan of up to 5 years.

More durable and elastic is the brand EL2842, which will last more than 10 years, without deteriorating the quality characteristics.

Potential damage to foam mattresses

Recently, the opinion has spread that foam is harmful to health, because the material releases harmful fumes. Despite the use of PPU for several decades, the debate about the appropriateness of its use does not subside.

It is known that the foam is made from completely synthetic components. Because of this, substances with a characteristic odor are released. But they quickly erode and do not cause harm to the body.

However, brands issued in violation of technology and the most budgetary, often continue to exude a smell throughout the life of the product. The vapors are compared with the substance released during combustion. But their concentration is so small that it is not necessary to talk about harm for a person.

Conclusion

Foam is widely used in furniture production. On a free sale, there are usually medium-density brands that are suitable for making children's furniture or backs of products. The density of foam rubber for the sofa should be above 30 kg / m ³ , but these types are produced directly for industrial purposes.

Often PPU used in the manufacture of mattresses. Now this material is the most common. This is facilitated by the positive characteristics that polyurethane foam has:

• affordable price;
• It does not burn out on its own (it burns only with the support of another source);
• Vapor tightness;
• Low thermal conductivity;
• Water resistance;
• Ease of maintenance;
• Convenience of transportation.

However, when choosing a foam mattress, it is necessary to take into account the presence of a block of springs. Nevertheless, despite the increased density, the material is soft enough. Therefore, in the production of furniture, additional devices are used to ensure sufficient rigidity. It can be coconut coir, independent springs and other inventions that improve the properties of foam rubber.

Despite the debate about the dangers and benefits of foam rubber, its properties are invaluable and allow producing things that are soft enough and at the same time resilient.