1 Type of coating structure
2/1: Coat the top surface of the steel sheet twice, coat the lower surface once, and bake the sheet twice.
2/2: Coat the top/lower surface twice and bake twice.

2 Usage of different coating structures
2/1: The anti-corrosion property and scratch resistance of the single-layer backside coating is poor, however, its adhesive property is good. The prepainted steel sheet of this kind is mainly used for sandwich panel;
2/2: The anti-corrosion property, scratch resistance and processing property of the backside coating of prepainted steel sheet is better, so it is widely used for roll forming. But its adhesive property is poor, so it is not used for sandwich panel.

Category & Coding of Prepainted Steel Sheet: