... wall&roof sandwich panels:light weight,heat and sound insulation,anti-corrosion and bending,easy to install,low cost Sandwich Panel ... small weight(1/20---1/30 of concrete roof), heat preservation, heat insulation(its heat ... resistance. The product is used to purify factory roof, protect and purify product industrial factory, storehouse, ... C---80º C5. Oxygen index: ≥ 26 wall and roof Sandwich panel