Density Of Memory Foam Mattress?

Memory foam is polyurethane with additional chemicals increasing its viscosity and density. It is often referred to as "viscoelastic" polyurethane foam or low-resilience polyurethane foam (see LRPu). Higher-density memory foam softens in reaction to body heat, allowing it for molding to a warm body in a few minutes. The faster speed of recovery of a foam to its original shape after a weight is removed is sometimes claimed as an advantage by memory-foam mattress producers, who may talk of "newer generation" foams with "faster recovery.