There are usually two ways to cool steel sheets: air-cooled and water-cooled.

1. The high quality PPGI corrugated roofing sheet is immersed in a molten zinc bath to adhere to a thin layer of zinc to the surface. It is mainly produced by the continuous galvanizing process, that is, the coiled steel plate is continuously immersed in a zinc-plated plating tank to form a steel sheet; the alloyed color corrugated steel sheet. This steel sheet is also produced by hot dip, but immediately after it is discharged, it is heated to about 500°C to form an alloy coating of zinc and iron. This PPGI corrugated roofing sheet has good adhesion and weldability of the coating.

2. The low price color corrugated steel sheet can be divided into two types: in-line annealing and off-line annealing according to different annealing methods, and they are called the protective gas method and flux method.

PPGI corrugated roofing sheets are widely used in the industry. Some inferior galvanized sheets will affect the use of the products. How can we avoid some unqualified materials in our purchase process?