Foam in the seats of furniture can be very firm or very soft and any comfort level in between. Similarly, the arms, cushions, backs and fronts may have foam padding of varying levels of density and compression. While there are no levels specific to furniture, there are grades of foam that describe the levels of density and firmness. The design, intended use and price of the furniture will determine the grade of foam used.
The density of foam is measured by the weight of one 12-inch cube of foam. The higher the density, the better the foam; a density of 1.8 to 3.2 is best for furniture seats. These weights may also be expressed as numbers; for example a weight of 1.5 pounds per cubic foot of foam may be written as #15.
The amount of pressure necessary to compress the foam by 25 percent is the Indentation Load Deflection, (IDL) rating of the foam. Seat foam on furniture requires firmness; an ILD rating of 30 to 40 is acceptable; back cushions require an IDL of 20 or less.
Density and Compression Combined.
A high-density foam may have a high IDL; this would be very firm foam. A high-density foam may have a low IDL; this would be a dense material that compresses much more easily than the high-density with a high IDL. Personal preference and usage of the furniture will determine the foam most suitable.
Ingredients in Foam
Foam is a biproduct of the petroleum industry and the price of foam is reflective of that industry's price fluctuations. Memory foam is latex foam which is a rubber-based product.
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