Fredrik Westin, Deflamo, presented industrial development of the Apyrum® PIN flame retardant system www.deflamo.se Today, a 500 -1 000 tonne/year pilot production unit is under construction in Karlshamm, Sweden. The Apyrum system acts by intumescence and is based on combinations of different mineral salts, including for example carboxylates, ATH, zinc hyrdoxystannate, calcium salts, a carbonate blower, inorganic phosphates, alkaline hydroxates and energy absorbing compounds.
The chemicals are based on food-grade mineral salts, to ensure low toxicity and low contaminant levels. The chemical salts combination is specifically adapted to each customer’s polymer or fibre and application and the key to performance is complete mixing (production using continuous crystallisation in a tube reactor), closely controlled particle size, and particle structuring in layers of different components. Applications to date include plasticised PVC for wall coverings (enabling to not use antimony), bio-based fibre composites, cellulose-based recycled insulation materials, wood/flour composites, latex binders for carpets, polyurethane foams.