Rubber fine powder Product origin: Crushed tires resulting from the recycling of a mixture of used tires of various categories (pv, cv, gv, hgv, pwv, cev, iv, agrarian, handling, motorbikes, etc). All the technical features of these tires comply with the regulations and standards requirements of france and of the european union. The rubber is made of a mix - in variable proportions - of 2 main types of synthetic rubber and of natural rubber. The 2 types of synthetic rubber are : - the sbr (styrene butadiene rubber) - the nbr (nitrile butadiene rubber) Apparent density: 428 kg/m3 or 0, 428 (adimensional). Industrial process of manufacturing: Exclusively with a mechanical crushing of the tires at ambient temperature. The process used does not require and does not reject any kind of solid, liquid or gas additives.