Electrophoretic coating (electrophoresis) is a highly efficient and uniform coating process widely used for sheet metal components. It involves depositing a paint film onto the metal surface using an electric field, ensuring excellent coverage even on complex geometries and hard-to-reach areas such as recesses and crevices.

The process begins with pre-treatment of the sheet metal, which includes cleaning to remove oils, rust, and contaminants, followed by phosphating to improve coating adhesion. The metal part is then immersed in a water-based electrophoretic bath containing charged paint particles. When an electric current is applied, the charged particles migrate to the oppositely charged metal surface (cathode for cathodic electrophoresis, anode for anodic electrophoresis) and deposit as a uniform film.

Cathodic electrophoretic coating is more commonly used in industrial applications due to its superior corrosion resistance. It produces a dense, smooth film with high edge coverage, making it ideal for components exposed to harsh environments, such as automotive chassis and industrial machinery. The thickness of the coating can be controlled by adjusting the voltage and immersion time, typically ranging from 10 to 30 microns.

After deposition, the coated part is rinsed to remove excess paint and then cured at high temperatures (usually 160-180°C) to crosslink the polymer molecules, forming a hard, durable film. This curing process ensures the coating has excellent mechanical properties, including scratch resistance and adhesion. Electrophoretic coating offers high material utilization (up to 95%) compared to spray painting, reducing waste and environmental impact. Its uniformity and efficiency make it a preferred choice for large-scale production, where consistent quality and cost-effectiveness are crucial.