Material which we have got used to call foam rubber is elastic polyurethane foam. Foam rubber is trade name of foam from this type of polyurethane foam. The main volume of foam occupies air (to 90% depending on other properties of foam rubber) which provides both compression, and material straightening.
Usual to us and material, so widespread in the world, - foam rubber - has appeared accidentally. The German scientists studied properties of polyurethane which actively made foam. Foam foam was by-product which long time was not considered as any useful element. In 1941 the Swiss engineers who of layers of foam foam have made mat, then mattress have used "useless" find of Germans, and after have at all replaced sawdust and waste of weaver's production with which filled padded stools and sofas, on foam rubber. Originally filler was cut tapes, but in use they quickly fell down therefore sheets of polyurethane foam began to cut out and glue under design of furniture. And there was the known filler of "Porolon" of the same name.
Advantages of furniture foam rubber
One of the main scopes of foam rubber and today is furniture production. Active use of foam rubber in soft elements of furniture design is explained by the fact that this material is ecologically harmless, hypoallergenic, does not emit dust, is not subject to influence of mold. If to speak about negative properties, then the main minus of foam rubber is its combustibility and allocation when burning number of harmful chemicals.
In furniture production the following types of foam rubber are used: - standard, - rigid, - soft, - elastic, - nonflammable.
Special requirements are imposed to furniture foam rubber: material has to be rather rigid at profitability of production.
Indicators on which the quality of foam rubber is estimated are its thickness and density. Than foam rubber density is higher, especially we will be long the term of its service. At the same time rather dense foam rubber is at the same time and extremely rigid, its application in furniture production is limited. Apply thicker to ensuring softness, but with smaller density foam rubber or stick together several diverse plates that gives effect of preservation, "storing" of form furniture. However, furniture foam rubber is not durable, growing old, it begins to be painted actively therefore 5-7 years later filler replacement is required. For zones most of which strongly are exposed to wear, for example, for backs and armrests of sofas, use just rigid foam rubber of high density which is often twisted the roller or form in form on production.
Production of foam rubber
Standard foam rubber is produced from main type of polyol. For production of foam rubber of the increased rigidity or, on the contrary, softness, additives from its special versions add to main type of polyol.
For production of highly elastic foam rubber mixes from two-three grades of special polyols are used.
As it was already mentioned, combustibility of foam rubber - almost only negative property of this material. To produce nonflammable foam rubber, addition in initial material of special powder - melamine and fire-retarding agents - the special additives guaranteeing resistance of foam rubber to high temperatures is required. Highly elastic foam rubber and nonflammable foam rubber are rather expensive and, therefore, are used by production of expensive models of furniture. For production of comfortable furniture of economy class the producers resort to the principle of multiple layers: in basis more economic types of foam rubber, and for top layer - highly elastic versions which are sewed with the main form are used. Foam rubber is actively used in construction and repair. It is often bought in quality shumo- and thermal insulation material.