PU Roof Sandwich Panels are composed of 3 layers, the external and internal is two dyed Galvanized or Aluminum corrugated plates, and core high density POLYURETAHE foam. Thanks to their properties the panels may be applied in object that require very high fire resistance, PU sandwich panel is the most effective acoustic materials used on construction.Take the 50 mm thick PU sandwich panel for example and the panel can absorb the sound over 30 db/m2. Widely used in the steel structure factory building, activities room, roof, wall, air clean room ceiling and partition.