PPGL sheets are processed by coating with zinc, silicon, and Aluminium. More precisely, the ingredients of the galvalume steel sheet have at least 55% Aluminium and 43.5% zinc, with the rest being silicon and other elements.
link:https://www.promisteel.com/galvanised-coated-steel/prepainted-aluzinc-steel/prepainted-aluzinc-steel-coils.html