Product description

Electrophoretic equipment is a device that makes charged particles migrate and deposit in electric field ‌. It is widely used in various fields, such as ‌ automobile, ‌ household appliances and ‌ corrosion resistant coating of iron and steel.

Product features and technology

Electrophoretic coating process is accompanied by electrolysis, electrophoresis, electrodeposition, electroosmosis and other four electrochemical physical phenomena, these phenomena are briefly described as follows:
Electrolysis: The decomposition of any conductive liquid when energized is called electrolysis. A well-known example is the electrolysis of water which can be split into hydrogen and oxygen. Electrophoresis equipment generally electrolysis is accompanied by the escape of gas at one or two electrodes, where oxidation and reduction reactions are carried out respectively. In the process of electrophoresis, water is electrolysed, hydrogen is released on the cathode, oxygen is released on the anode, and the metal anode produces a dissolution, dissolving metal ions.
Electrophoresis: Positively charged colloidal resin particles and pigment particles in a conductive medium are moved towards the cathode by the electrophoresis process under the action of an electric field.
Electrodeposition: The precipitation of paint particles on the electrode is called electrodeposition. In cathodic electrophoretic coating, positively charged particles condense on the cathode and negatively charged particles (ions) gather on the anode. The first step in electrodeposition is the electrochemical decomposition of water (electrolysis). If the PH of the tank is neutral, the reaction on the cathode is to form hydrogen and hydroxide ions (OH-). This reaction results in the formation of a highly alkaline interface layer in the cathode surface region. The coating is deposited when cations (resins and pigments) react with hydroxide ions to become insoluble.
Electroosmosis: The coating film just deposited on the surface of the coated material is a semi-permeable film, under the continuous action of the electric field, the water contained in the coating film is seeped out from the coating film to the tank liquid, so that the coating film dehydration, this phenomenon is called electroosmosis. Electroosmosis changes the hydrophilic film into a hydrophobic film and densifies the film due to dehydration. The wet coating film of electroosmotic electrophoretic coating can be touched by hand and does not stick to hands. The bath liquid attached to the wet coating film can be washed away with water.

Argument

1. Electrophoresis power supply
Output voltage: Generally between 50-1000V, different electrophoresis processes and workpiece requirements are different, such as car body electrophoresis often uses 300-500V.
Output current: range from tens of amps to thousands of amps, such as small hardware electrophoresis may only need tens of amps, large bus body electrophoresis requires thousands of amps.
2. The temperature control range of the electrophoresis tank: generally 25-35 ℃, maintained by the temperature control system, the temperature affects the stability of the electrophoresis paint and the coating effect.
3. Circulation filtration system
Circulation flow: The volume of electrophoresis liquid circulated every hour, generally 3-4 times the volume of the electrophoresis tank/hour, to ensure uniform composition of the electrophoresis liquid. Filtration accuracy: usually in 1-50μm, common 5μm, 10μm, to ensure the electrophoresis solution clean, prevent impurities from affecting the quality of the coating.
4. Ultrafiltration system
Ultrafiltration membrane area: Determine the processing capacity of the ultrafiltration system, from a few square meters to dozens of square meters, the larger the area, the stronger the processing capacity.
5. Drying equipment
Drying temperature: generally 160-180 ° C, different electrophoretic paint requirements are different, such as acrylic electrophoretic paint drying temperature may be 140-160 ° C. Drying time: usually 20-30 minutes, related to temperature, workpiece size, coating thickness.