... water absorption of 4-7% 3.20mm-100mm Wall thermal insulation XPS board , made from polystyrene resin and other additives, by ... continuous process of extrusion,become a rigid foam board, called XPS insulation board. Thanks to the extrusion process,the surface is very ... and color corrugated board.For the bedding under floor, play the role of heat insulation, moisture-proof, sound-proof.For central air ...