2005 Volume 54 Issue 8 Pages 396-398
We applied poly (ethylene terephthalate) (PET) homopolymer, in stead of PET copolymer, to powder coating on galvanized steel. Despite the concern over internal stress originated from its rigid molecular structure, pin-hole-free thick PET overcoating was formed with good adhesion to the substrate. This coating coupled with the sacrificial corrosion of zinc undercoating provided an excellent corrosion protection capability against salt-water spray (6000h) and seaside weathering (5 years) tests. The coating had enough strength to withstand scratches and impacts that can be inflicted during the constructi on and use. These properties are equivalent to those of the PET copolymer coating, which has been successfully used for outdoor telecommunications plants over 15 years. The introduction of PET homopolymer reduces the cost for raw material, and recycled PET can be employed.