The new co-extrudable Ultradur® PBT has a melting point closer to that of PVC which enables an optimised one-step extrusion process for the manufacturing of window profiles. Ultradur® PBT is high strength and lightweight reinforcement material that provides the mechanical properties required to withstand strong winds. Compared with steel, it greatly reduces heat transfer through the window profiles which provides excellent thermal insulation.adidas NMD kaufen