Electrocoat Bath Process
The electrocoat bath consists of deionized water and paint solids. The deionized water acts as the carrier for the paint solids, which is under constant agitation. The paint solids consist of resin and pigment. Resin is the backbone of the final paint film and provides corrosion protection, durability, and toughness. Pigments are used to provide color and gloss.
The electrocoat process is driven by a DC rectifier, used to regulate and control the paint film build on the parts. The tank contains electrodes, which carry an electric charge that is the same as the paint particles and opposite of the metal parts being coated. When voltage is applied from the rectifier, paint is driven away from the electrodes and to the part where it is electrodeposited to the metal surface. Often, the electrodes are surrounded with semi-permeable membranes that are used to control bath pH. The paint tank uses pumps to provide the agitation necessary to feed particle filters which keep the paint clean. The pumps also feed the ultrafilters, which generate post rinse permeate and feed heat exchangers so that the paint bath temperature can be controlled. The tank and all of the supporting equipment are custom designed and sized to meet the coated surface area per minute demand.