perlite fire board : fireproof door core sizes:915mm*2135mm 600mm*800mm thickness:25~50mm perlite fire board1. FeaturePerlite fire door core is consisting of expanded perlite and inorganic glue. With the chatacters of light(kow bulk density), high hydrophobe rate , high strength, low thermal conductivity and easy-to use, Hydrophobel perlite board/ tiles are widely used in roof, wall, barns as ...