PrePainted Galvanized Steel Coil (PPGI) and Pre-Painted Galvalume Steel Coil (PPGL) is a kind of building materials, with galvanized sheet and aluzinc sheet as the substrate, after pretreatment (degrease and chemical treatment) and liquid dope with several layers of color, then firing and cooling, finally the palte steel is called pre-painted galvanized steel coil (PPGI) or pre-painted galvalume steel coil (PPGL).