polyurethane sandwich panel water-proof and fire-retardant , lightweight , anti-seismic,sound insulation and lower noise polyurethane decorative wall panel 16 mm 1) Intruduction ... ,2) the inter-layer is the rigid high-density PU foam thermal insulation layer with fire-retardant treatment , 3) the ... size : 3800*380*16mm3, Package : 1.444sqm / pc 8pcs /carton sandwich panel-insulation exterior wall ...