Research on the Control Process of Paint Adhesion on the Edge of Tinplate

To solve the problem of poor paint adhesion on the edge of tinplate，electrochemical workstation，paint film adhesion tester and potentiostat were employed to study the effects of reflow process，passivation charge density，strip speed and passivation electrode plate width on the coating，paint adhesion and corrosion resistance of tinplate edge.Results showed that the increase of the passive film content on the edge of the tinplate was the main reason for the deterioration of the paint adhesion.When the passivation charge density was reduced from 0.5 C/dm2 to 0.1 C/dm2，the adhesion of the paint film at the edge and middle of the tinplate could reach level 1，but it would cause insufficient corrosion resistance.Reducing the belt speed to 350 m/min or narrowing the passivation plate width to 840 mm could reduce the edge effect of passivation，and the paint film on the edge and middle of the tinplate possessed a paint adhesion of grade 1 and a corrosion resistance of grade 0.Hence，narrowing the passivation plate was the best choice to improve the adhesion of the paint film on the edge of the tinplate.