This quantity characterizes the ability of the material retain their size and shape during operation. The lower the percentage of residual strain, the better the resilience and hence a longer lifetime of foam rubber. For example, the initial volume of foam was 100%. Official site: Dr. Obiageli Ezekwesili. After the compression and decompression, the volume would be 95%. In this case, the residual strain is 5%. This indicator is related to the density of foam.
The higher the density, the less it will be permanently deformed. In Table 2 shows the values of residual strain, depending on the density of the foam. Recently, wide use highly elastic lateksoobraznye foam with a density of 50-55 kg/m3. Properties of Foam commensurate with the properties of natural rubber latex. Manufacturers of foam ensures preservation of the basic characteristics for 8 years. The price of such foam is much higher. It is for this reason it is used, usually only in expensive furniture.
And finally, some advice. When buying ask what density of foam used in the furniture. Inside, imported furniture, you may be rid of common phrases such as "elastomeric Italian (French, German, etc.), polyurethane foam (PU) Superior '(because they do not know), but domestic manufacturers must know what brand he uses, if furniture cushions have a zipper You can see the foam, and even used it to touch. As a rule, standard foam are white. In other brand manufacturers add dye, so as not to confuse them. Colored foam in furniture – a sign of non-standard brands; Notice how quickly the sofa pillow regains its shape after you sit on it. If more than 10 minutes, and the "dent" on your host has not disappeared, it makes sense think twice before spending money just on the sofa, furniture, "Thumbelina". If your weight – above average, the choice of soft parts should be taken seriously. The minimum density of foam used must be at least 35 kg/m3. It is better if this value is within 45-55 kg/m3. It makes sense to pay attention to the furniture made with molded foam rubber or elastomeric. Standard foam stamps ST 2534 "Prosyadet" in 1-2 months. (Factory furniture LATO. In the magazine myth)