Bansi Kaul, MCA Technologies, presented testing of different PIN FR additives in polypropylene: calcium carbonate, ultracarb (natural magnesium mineral supplied by OMYA), metal hydroxides (ATH, MDH), borates, nanoclays, including in combination with his company’s PPM-triazine additives (a nitrogen containing polymeric PIN FR).
He noted that the minerals can generate ceramic metal oxynitrides during combustion, contributing strength and heat resistance to char and also a reflective effect (so protecting polymers from melting and decomposition caused by heat and which feeds feed fire). He noted that coating of inorganic PIN FRs with siloxane can improve dispersion, polymer moisture resistance and mechanical properties and enable achievement of fire performance at lower FR loading through a more compact and resistant char formation.