Mechanism of Press Scar on Appliance Prepainted Steel Sheet

Defects of press scar often occur after the appliance prepainted steel sheets are coiled. In order to prevent the defects from occurring, the influencing factors and the surface appearance of the press scar on the appliance prepainted steel sheet were studied and the glass transition temperature (Tg) of the prepainted coating was measured, and the formation mechanism of the press scar was discussed. The results show that the occurring and the properties of appearance of the defect were related to the difference in the gloss of the prepainted coating surface between the up and down sides. The press scar would become more severe as the difference in the surface gloss on the up and down sides and the environmental temperature was higher. In addition, the effect of Tg of the prepainted coating was also noticeable.