... is no more than 120`C under testing 45mm thick door core, inside wall and etc. Characteristic features:1. Fire ... to envirment. Content and specification:Contents: 85% perlite grain, 5% glass fibre mesh, 5% plaster, 5% other inorganic materials.Production specification ... features, Perlite board is used widely as steel and wooden door core, partition, inside material of roof and exterior wall, ...