Cold plate of polyethylene and polystyrene as raw materials, addition now the best performance of polyurethane sandwich panels, polystyrene foam out of thin insulation material density, not enough insulation, usually with special equipment inside, poly ethylene is a good raw material, than against, can foam density appropriate, effective insulation, high load bearing capacity of the insulation material. Polyurethane board insulation performance is best, do not absorb moisture, but the price is slightly higher. Cold plate of protective material the following species: A, embossed aluminum, newspaper 
 Stainless steel plate C color zinc plate D, salinization steel plate, standard plate: 1.0mm galvanized sheet