Biesterfeld is now distributing Elkem’s low specific surface area silica, as a performance synergist or partial filler replacement, for flame retardant rubbers. The special amorphous silica’s low BET (Brunauer–Emmett–Teller) surface area, 20 – 25 m2/g, means that the material is low reinforcing (does not influence mechanical performance), inert and non-porous, so does not absorb plasticising components. In rubber, its broad particle size distribution enables good dispersion, and it can improve processing and properties such as dynamic fatigue and surface quality. It acts as a synergist with a wide range of flame retardants, in particular reducing dripping and improving char integrity in halogen-free compounds, or as a partial replacement of antimony trioxide. Biesterfeld has been operating international trading for over 110 years, is based in Hamburg, Germany, with 800 staff worldwide, specialised in plastics and additives, rubbers and compounds.
www.sidistar.com. “Biesterfeld granted distribution rights for Sidistar® from Elkem ASA in German Rubber market”, 18th March 2020 https://www.biesterfeld.com/en/es/article/biesterfeld-granted-distribution-rights-for-sidistarr-from-elkem-asa-in-german-rubber-market/