The purpose of pretreatment is to remove the oil pollution on the workpiece surface and form a dense phosphating coating to improve the corrosion protection ability of the workpiece, and the electrophoretic coating enhances the anti-corrosion ability of the workpiece. The pretreatment includes three parts: degreasing (degreasing), removing rust and phosphating. Phosphating is the central link. Removing oil and rust is the preparatory process before phosphating. Therefore, in the production practice, we should focus on Phosphating as well as the quality requirements of phosphating and do well in the work of removing oil and rust, especially the interaction between them.
Pretreatment line the whole process involves chemical and electrochemical reaction, has the characteristics of high degree of automation pretreatment, manual pretreatment, less participation of environmental protection, has become a modern painting is preferred. Phosphating treatment can significantly improve the corrosion resistance and adhesion of the coating. Phosphating film is a corrosive reaction on the metal surface under proper control conditions, resulting in the formation of a metal compound film on the surface of the metal. As mentioned above to obtain the complete fine phosphating film, the premise is that under certain conditions and strict control before the road and the parameters and to ensure good site management level. The most common problems such as phosphating, phosphating, phosphating yellow rust twill flowering.
Pretreatment process for pre washing, pre degreasing, degreasing, water washing, a two meter conditioning, phosphorization, water washing, clean spraying. A fan is installed at the top of the degreasing tank, the surface adjustment and the top of the phosphating trough.