The working principle of 1. electrophoretic paint

Electrophoresis is an electrophoretic coating in the yin and yang poles, applied to the role of voltage, charged coating ions move to the cathode, and the alkaline effect generated by the cathode surface to form insoluble matter, deposited on the surface of the workpiece. It includes four processes:

1. Electrolysis (decomposition)

The cathode reaction is initially an electrolytic reaction, generating hydrogen and hydroxide ions OH. This reaction causes a highly alkaline boundary layer to form on the cathode surface. When cations and hydroxide react to become water-insoluble substances, the coating film is deposited, and the equation is: H2O & rarr;OH H

2. Electrophoresis (swimming, 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)

On the surface of the coated workpiece, the cationic resin acts on the surface of the cathode to neutralize and precipitate no deposits, which are deposited on the coated workpiece.

4. Electroosmosis (dehydration)

The coating film on the surface of the coating solid and the workpiece is translucent and has most pores. Water is drained from the cathode coating film. Under the action of the electric field, the coating film is dehydrated, and the coating film is adsorbed on the surface of the workpiece, and the whole electrophoresis process is completed.

Process Route and Function of 2. Epoxy Electrophoretic Paint

Epoxy electrophoretic paint This kind of electrophoretic paint is mainly used in large industrial enterprises, with high requirements for anti-corrosion and anti-rust. The varieties are black, gray, red, yellow and other colors. It is mainly used in the automobile industry, but also in the bicycle industry, motorcycle industry, home appliance industry, etc. The electrophoretic paint film is opaque.

1. Process route

Hanging on & rarr; Degreasing & rarr; Hot water washing & rarr; Cold water washing & rarr; Surface conditioning & rarr; Phosphating & rarr; Water washing & rarr; Water washing & rarr; Pure water washing & rarr; Electrophoresis & rarr; Recovery & rarr; Recovery & rarr; Pure water washing & rarr; hanging (rusty workpieces need to be derusted and then electrophoresed) 2. Role of each station

(1) Degreasing: Remove the oil stains on the surface of the workpiece.

(2) water washing: cleaning the surface of the workpiece residual liquid.

(3) Table tone: The surface of the workpiece is activated to facilitate the formation of a phosphating film on the metal surface.

(4) phosphating: phosphating film is a porous crystal structure, which plays a good role in the binding ability between the coating and the metal and preventing corrosion.

(5) Pure water washing: avoid the acid, alkali and salt of the previous process into the electrophoresis tank to pollute the paint tank.

(6) electrophoresis: in the measurement of good voltage and time, the formation of electrophoretic film.

(7) recycling: U/F liquid washing, reduce the waste of paint, recycling to reduce production costs.

(8) Baking: The paint film is cured at a high temperature of 160 ℃ ~ 180 ℃.