Brown Factice (Sulfur-Vulcanized Oil Extender)

Brown Factice is produced by vulcanizing vegetable oil (typically rapeseed or linseed oil) with sulfur at elevated temperatures, resulting in a rubber-like solid that acts as a non-reinforcing extender and processing aid. It improves extrusion smoothness, reduces die swell, and imparts a greasy texture to uncured rubber compounds. Brown factice is widely used in erasers, cable insulation, and sponge rubber to improve extrusion behavior and compound softness.