Cone calorimeter evaluation on fire resistance of rigid polyurethane foams filled with nanoclay/intumescent flame retardant materials

Natural minerals like calcite, clay, kaolin and dolomite are used as fillers up to 15 wt % in productions of rigid polyurethane foams to reduce production costs and enhance the fire resistance. In general, only filler additions do not significantly enhance the fire resistance of the foams. Therefore, different flame retardant materials are added together with the fillers. In this study, effects of 10 wt % nanoclay/5 wt % an intumescent flame retardant additions on combustion behaviour of rigid polyurethane foam were investigated by cone calorimeter tests. Heat release rate, total heat released, ignition time, smoke production and carbon monoxide emissions of neat and nanoclay/intumescent flame retardant filled polyurethane foams were examined. The experimental results showed that 10 wt % nanoclay/5 wt % the intumescent flame retardant addition significantly improved the fire resistance.