Main process parameters affecting home appliance coating equipment

1. Voltage

Electrophoretic coating adopts constant voltage method, the equipment is relatively simple and easy to control. The voltage has a great influence on the paint film; the higher the voltage, the thicker the electrophoretic paint film, and the coating ability can be improved correspondingly and the construction time can be shortened for the parts that are difficult to paint. However, if the voltage is too high, the surface of the paint film will be rough, and the phenomenon of "orange peel" will easily occur after drying. The voltage is too low, the electrolysis reaction is slow, the paint film is thin and uniform, and the swimming penetration is poor. The choice of voltage is determined by the type of paint and construction requirements. In general, the voltage is inversely proportional to the solid content of the paint and the paint temperature, and directly proportional to the distance between the two poles. The surface of steel is 40～70V, the surface of aluminum and aluminum alloy can be 60～100V, and the surface of galvanized parts is 70～85V.

2. Electrophoresis time

The thickness of the paint film increases with the extension of the electrophoresis time, but when the paint film reaches a certain thickness, if the paint film reaches a certain thickness, continue to extend the time, and the thickness cannot be increased. On the contrary, the side reaction will be aggravated; on the contrary, if the electrophoresis time is too short, the coating is too thin. The electrophoresis time should be based on the voltage used, and under the condition of ensuring the quality of the coating, the shorter the better. Generally, the electrophoresis time for workpieces is 1 to 3 minutes, and for large workpieces, it is 3 to 4 minutes. If the surface geometry of the coated object is complicated, the voltage and time can be increased appropriately.

3. Paint temperature

The coating temperature is high, the film formation rate is fast, but the appearance of the paint film is rough, which can also cause the coating to deteriorate; the temperature is low, the amount of electrodeposition is small, the film formation is slow, and the coating film is thin and dense. During the construction process, as part of the electrical energy is converted into heat energy during electrodeposition, the mechanical friction in the circulation system generates heat, which will cause the temperature of the paint to rise. Generally, the temperature of the paint solution is controlled at 15-30°C in some aspects.