Technical Information about Polyurethane Foams
There is frequent confusion about the type of foam used in mattresses produced for use in a healthcare and domestic market. People are often uncertain how they should interpret the information provided by manufacturers. In general, the type of foam used is polyurethane foam. This is available in both hard and soft versions. The actual hardness or softness is determined during production of the foam by the use of additives such as water.
It is important to note that this has nothing to do with the density or specific gravity of the foam. That is expressed in kilograms per cubic meter (kg/m³), i.e. the weight of a block of foam measuring 1 x 1 x 1 metres.
The density of the foam is to a large extent responsible for its quality. In other words, a block of foam measuring 1 x 1 x 1 metres with a density of 43 kg/m3 has less “mass” (i.e. amount of foam) than one with the same dimensions but a density of 55 kg/m3.
In other words the lower the density, the lower the quality of the foam and the shorter its durability, especially in intensive use at a hospital or nursing home.
Visco-Elastic Foam
Slow foam is also made of polyurethane but special additives give it its “slowness”. Unlike other types of foam, which immediately spring back to their original form when you press and release them, slow foam – as the name implies – only does so gradually.
Slow foam also has the unique property of conforming to the shape of your body due to your weight and body temperature. This means that pressure is distributed evenly, thus protecting sensitive parts of the body that may be at risk of developing bedsores.
Safety and Environmental Aspects
It is important for foam to be produced in an environmentally friendly manner, without using CFCs. Polyurethane foam is basically an environmentally friendly product and can be recycled both mechanically and chemically.
Safety aspects are playing an increasingly important role. Most manufacturers are capable of producing a polyurethane foam that complies with the CRIB5 standard for fire retardancy but few can produce a slow foam that meets that standard.