Process principle of electrophoresis (sheet metal surface treatment)

Electrophoresis methods are divided into anode electrophoresis and cathode electrophoresis. When the coating particles are negatively charged, the workpiece is an anode, and the coating particles attach the film to the workpiece under the action of electric field. On the contrary, if the coating particles are charged, the workpiece is the cathode, and the coating particles attach the workpiece to the film, which is called cathodic electrophoresis.

Anodic electrophoresis is characterized by the relatively simple installation of cheap raw materials (usually 50% cheaper than cathodic electrophoresis) (usually 30% cheaper than cathodic electrophoresis); The corrosion resistance of the coating with low technical requirements is worse than that of cathodic electrophoresis (the service life of cathodic electrophoresis is about 1 / 4).

The reason for the high corrosion resistance of cathodic electrophoretic coating is that the working block is a cathode, there is no anodic dissolution, and the electrophoretic coating (generally nitrogen-containing resin) on the surface of the working block and the phosphate film is not damaged has a protective effect on the metal. The coatings used are: high price and high quality.