PPGI uses galvanized sheet (with a zinc coating) as the base material. However, PPGL is based on aluminized zinc plate, which is plated with 55% aluminum, 43.3% zinc and 1.6% silicon. PPGL is more heat and corrosion resistant. Its service life under normal conditions can reach more than 50 years. PPGI is about 20-30 years. But PPGL roofing panels are more expensive than PPGI roofing panels. PPGI is on the basis of galvanized roll with a certain technology and then covered with color coating, give the product more color, and this color rich and beautiful surface makes it more widely used. The heat resistance of PPGL sheet is better than that of PPGI sheet. PPGL sheet can withstand 315℃ temperature. In addition, PPGL panels have better corrosion resistance than PPGI.