What is memory foam?

Memory foam is made from polyurethane with additional chemicals that increase its viscosity level, thereby increasing its density. It is often referred to as visco-elastic polyurethane foam. Depending on the chemicals used and its overall density, it is firmer in cool temperatures and softer when warm. Higher density memory foam reacts to body heat which allows it to mould itself to the shape of a warm body within a few minutes. A lower density memory foam is pressure-sensitive and will mould more quickly to the shape of the body. The example often used to demonstrate its properties is that a hand pressed into the foam and then removed will leave a clear impression in the foam.

IFD ratings explained.

The property of firmness (hard to soft) of memory foam is used in determining comfort. Firmness is measured by a foam's IFD (Indentation Force Deflection) rating.

IFD measures the force (in pounds) required to make a dent 1 inch into a foam sample 15" x 15" x 4" by a 8 inch diameter (50 sq in) disc - known as IFD @ 25% compression. IFD ratings for memory foams range between super soft (IFD 10) and semi-rigid (IFD 12). Most memory foam mattresses are firm (IFD 12 to IFD 16).

The importance of density.

Memory foam beds are available in a range of densities. We use two main densities when creating our mattresses. A 4.2 lbs density and a 5.3 lbs density.

Density ratings are not the only thing that determine the feel of a memory foam mattress. A 5.3 lbs memory foam mattress can have an IFD rating of 10 and feel very soft , or an IFD rating of 18 and feel very firm.

Density ratings are usually an indication of the quality of the memory foam mattress. A memory foam mattress with a density of 4.2 lbs will last approximately 10 - 15 years. A memory foam mattress with a density of 5.3 lbs will lastapproximately 15 - 20 years.