1. Electrophoresis time

The thickness of the paint film increases with the extension of the electrophoresis equipment time, but when the paint film reaches a certain thickness, continuing to extend the time will not increase the thickness, but will aggravate the side reaction; on the contrary, if the electrophoresis time is too short, the coating will be too thin. The electrophoresis time should be based on the voltage used, and the shorter the better under the condition of ensuring the quality of the coating. The electrophoresis time for general 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 complex, the voltage can be appropriately increased and the time can be extended.

2. Voltage

The electrophoresis coating adopts the constant voltage method, and the electrophoresis 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 electrophoresis paint film, and the coating capacity can be correspondingly improved for difficult-to-coat parts, shortening the construction time. However, if the voltage is too high, the surface of the paint film will be rough, and the "orange peel" phenomenon will easily occur after drying. If the voltage is too low, the electrolysis reaction will be slow, the paint film will be thin and uniform, and the permeability will be 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 coating and the paint temperature, and is proportional to the distance between the two electrodes. The surface of steel is 40-70V, the surface of aluminum and aluminum alloy can be 60-100V, and the galvanized parts are 70-85V.

3. Paint temperature

The paint temperature is high and the film forming rate is fast, but the paint film has a rough appearance and will also cause the paint to deteriorate; the temperature is low, the electrodeposition amount is small, the film forming is slow, and the coating is thin and dense. During the construction process, since 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 paint temperature to rise. Generally, the paint liquid temperature is controlled at 15-30℃ in some aspects.

4. Paint resistance

The impurity ions brought into the electrophoresis tank from the previous process of the coated object cause the paint resistance value to decrease, resulting in roughness, unevenness and pinholes in the paint film. During the coating construction, the paint needs to be purified. In order to obtain a high-quality coating, an anode blue device can be used to remove impurity positive ions such as ammonium, calcium, and magnesium.