Ecoat, also called electrocoating, is a process to consider for complex parts.
Manufacturers in many sectors want solutions that will improve performance and meet the increasingly complex market demands that encompass different substrates, product designs and pretreatment options. With excellent mechanical properties, superior corrosion resistance, and enhanced edge protection, electrocoating delivers superior performance.
The electrocoating process uses electrically charged particles to coat a conductive part. Paint is applied to a part at a specific film thickness that is determined by the amount of voltage applied. The deposition is self-limiting and slows down as the applied coating electrically insulates the part.
One of the advantages of e-coat is its ability to provide complete surface coverage with unrivaled film uniformity due to its throwpower. Electrocoat solids are deposited in the areas closest to the counter electrode first and then as these areas become insulated to the current, solids are forced into the recessed bare metal areas to provide full coverage – that’s throwpower.
The e-coat process consists of four distinct phases. The first phase is the pretreatment. Pretreatment is a multi-step phase involving cleaning, rinsing, conditioning, rinsing, conversion coating, rinsing, post-treatment, and deionized water rinsing. Next, the parts are immersed in an electrocoating bath consisting of 80-90% deionized water and 10-20% paint solids. In the bath, direct current is applied between the parts and a “counter” electrode. Paint is attracted to the part by the electric field and deposited onto the part. The third phase is rinsing which returns excess paint to the tank. Finally, parts are baked in an oven to cure and cross-link the coating.
All coatings, including electrocoating, are made from a polymeric resin or binder, pigments, and solvents and diluents. The resin provides the strength of the final paint film and performance properties. Pigments provide color, luster, and additional corrosion protection. The solvents help to produce smooth film appearance.
E-coat is typically chosen over other coating technologies because of its lower total applied cost. The low total applied cost is made possible because electrocoating is an efficient, automated, precise film build, high paint transfer process. The process yields a consistent part-to-part, high performing coating, with no need to inspect or re-work parts due to paint defects.
E-coat provides customers with the ability to coat complex parts or hard to reach surfaces. Combined with the fact that manual labor is not needed to apply paint, the electrocoat system is a fast-moving and highly productive coating process.