... 600mm*800mm thickness:25~50mm Perlite insulation boardPerlite board characteristics:1. Natural, enviromental-protection oriented, no poison and no radioactivity2. Fireproof, ... customers' request Product use:The expanded perlite fireproof door board is mainly used to provide fireproof materials for steel and ... , Ballrooms, entertainment centers, factories, activity rooms, etc. Perlite insulation board