What is high density sponge

Sponge in the industry to distinguish method based on density to differentiate, sponge density is KG/M3. Is that every cubic meters of the weight of the sponge. Density is an important indicator of the material, high density sponge that the inside of the space is small, the greater the quality. Such as: forty density is a cubic meters of the weight of the sponge is forty kilograms, fifty density is fifty kilograms per cubic meter. Generally high density sponge hardness is high, but would not rule out some high density sponge will add super soft additives, let sponge become super soft, used to do sound-absorbing cotton, sofa cushion, soft package material. Low surface used for general protection materials.
The same density sponge soft hard degree is not certain. General do sofa cushion sponge density of about 35 have soft, hard, super soft and specifications. Do the mattress is generally about 22. The so-called high density sponge salesman is introducing products often use the term. According to the national customs department explanation is density was 45 for high density, medium density < 45 > and < and, low density.