Bulk density

The bulk density, also called apparent or geometric density or specific gravity, is the density of a porous solid based on the volume including the pore spaces:

The counterpart of the bulk density is the true density. True density and bulk density of non-porous body are the same:

The ratio of raw and true density, the relative density. Their difference to 1 (or 100% ) is the total porosity ( the sum of the open and closed porosity).

Relationships:

• In construction materials, an increasing bulk density generally has a positive effect on sound insulation and negative effect on the thermal insulation.
• Wherein material that is homogeneous, except for the voids ( foams and other foam materials), one can determine the density of the comparison of the volumes before and after foaming.
• For mattresses refers to the " density ", which is often cited as the main quality feature on the mass of the processed raw material ( eg, plastic or latex). That is, a finished mattress with a higher density has ( the same dimensions ) has a lower air or pore volume, higher (raw) density and a lower porosity than a comparative mattress.