Electrophoretic paint is one of the effective methods for coating metal parts. Electrophoretic coating is a special coating method. The conductive coating is immersed in the low concentration electrophoretic coating tank diluted with water as the anode (or cathode), and the corresponding cathode (or anode) is added in the tank. After a period of indirect direct current action between the two electrodes, a uniform and fine coating film insoluble in water is deposited on the surface of the coated object.
There are four chemical and physical changes in the process of electrophoretic coating, namely electrolysis, electrophoresis, electrodeposition and electroosmosis. The electrophoretic coating manufacturer will introduce two points to you: electrolysis and electrophoresis
(1) Electrophoresis:
In colloidal solution, charged colloidal ions dispersed in the medium move to electrodes with different charges under the action of DC electric field. Because colloidal ions are subject to the resistance of the dispersion medium during their movement, the resistance to ion migration in the electric field is far greater than that in the real solution, and the movement speed is slow, just like the migration in the dispersion medium, so it is called electrophoresis. The electrophoretic speed of colloidal particles depends on the electric field strength and the structural characteristics of the double electric layer when the water-soluble resin is dispersed.
(2) Electrolysis:
When a DC electric field is applied to the aqueous solution containing electrolyte, water will be electrolyzed in the electric field, oxygen will precipitate in the anode area, and hydrogen will precipitate in the cathode area.
