The working principle of electrophoretic paint

Electrophoresis is that the electrophoretic paint is applied to the cathode and the anode, and the charged paint ions move to the cathode under the action of voltage, and form insoluble matter with the alkali generated on the cathode surface to deposit on the surface of the workpiece. It includes four processes:

1. Electrolysis (decomposition) is the electrolysis reaction at the beginning of the cathode reaction to generate hydrogen and hydroxide ion OH. This reaction results in the formation of a highly alkaline boundary layer on the surface of the cathode. Water-insoluble substance, coating film deposition, the equation is: H2O→OH + H2, 2

2. Electrophoresis (movement, migration) The cation resin and H + move to the cathode under the action of the electric field, while the anion moves to the anode.

3. Electrodeposition (precipitation) is performed on the surface of the coated workpiece, and the cationic resin reacts with the cathode surface to neutralize and precipitate the undeposited precipitate, which is deposited on the coated workpiece.

4. The electroosmotic (dehydration) coating solid and the coating film on the surface of the workpiece are translucent, with many pores, water is discharged from the cathode coating film, and the coating film is dehydrated under the action of the electric field. The coating film is adsorbed on the surface of the workpiece to complete the entire electrophoresis process.

(1) Epoxy type electrophoretic paint. This type of electrophoretic paint is mainly used in large-scale industrial enterprises. It has high requirements for corrosion and rust resistance. The varieties are black, gray, red, yellow and other colors. They are mainly used in the automobile industry, bicycle industry, Motorcycle industry, home appliance industry, etc., electrophoretic paint film is opaque. 1. Process route: hanging → pre-cleaning → degreasing → hot water washing → cold water washing → pickling → water washing → meter adjustment → phosphating → water washing → water washing → pure water washing → pure water washing → electrophoresis → recycling → recycling → pure water washing → pure Washing → enter the oven → hang down