Electrocoating – The Technology
Electrocoating is a finishing process technology used worldwide to achieve high quality, low-cost finishes at a level of efficiency and environmental compliance, no other finishing method approaches. The process involves submerging metallic products in a charged paint bath and electrically depositing the paint onto the product. With this process, paint only adheres to the intended product. The coating thickness is generally dependent upon the voltage applied to the paint.
End Use Applications and Electrocoat Properties
|Market Segment||Properties Added by Electrocoating|
|Agriculture Equipment||High Gloss, Color Control, Weatherability, Corrosion Resistance|
|Appliance||Corrosion and Stain Resistance, Color Control|
|Automotive||Corrosion and Chip Resistance, Weatherability|
|Automotive Components||Corrosion, Chemical and Chip Resistance|
|Containers (Cans)||Barrier and Chemical Resistance, FDA-Approved, No Effect on Flavor|
|Electrical Switchgear||Corrosion Resistance and U.L. Approval|
|Fasteners||Corrosion and Edge Coverage|
|Frames||Corrosion, Chemical and Chip Resistance|
|HVAC||Corrosion Resistance, Color Control, and Weatherability|
|Laboratory Furniture||Chemical, Stain, and Corrosion Resistance, Color Control|
|Lawn and Garden||Corrosion Resistance and Weatherability|
|Metal Office Furniture||Color Control, Hardness, and Stain Resistance|
|Plated Objects||Clarity, Weatherability, Corrosion Resistance|
|Printed Circuit Boards||Edge Coverage and Hardness|
|Railway||Corrosion and Chip Resistance, Weatherability|
|Structural Steel||Corrosion Resistance and Weatherability|
|Heavy Duty Truck and Bus||Corrosion and Chip Resistance, Weatherability and Color Control|
|Wheels||Corrosion and Chip Resistance, Weatherability|
- Throw power for 100% coverage of complex parts
- Uniform film thickness
- Benchmark corrosion protection
- Superior edge coverage
- Product and process consistency
- Compatibility with other coating technologies
- One coat applications for optimized performance even under extreme performance conditions
- Low temperature cure in many applications
- Excellent color and gloss control
- Stain resistant
- Chemical resistant
- Detergent resistant
- System automation
Utilization – Film thickness is easily controllable, unlike other types of coatings. With close-looped recycling, all coating paid for goes on the product.
Maintenance – Less time and money is spent on cleaning and maintaining finishing equipment. As a result, less cost is passed onto the customer.
Labor costs – Unlike other applications, electrocoating requires a smaller worker pool. There are sprayers, paint mixers, touch-up personnel, and strip tank operators for other finishes and coatings; these workers are eliminated or reduced by electrocoating.
Electrocoating – The Process
Using a water-based chemistry supplied and maintained by PPG, we pretreat non-aluminum stampings and assemblies to prepare the metal substrate for electrocoating. The process begins with two caustic cleaning stages, followed by two rinses, a conditioner stage, zinc phosphate coating, a sealer, and two more rinses before e-coat.
Utilizing PPG-supplied e-coat products, pretreated parts are inducted into a 33,500-gallon e-coat tank that is cooled by chiller. Programmable rectifiers and 32 anodes in the e-coat tank ensure consistent film build regardless of size. A large external cam mechanism provides end-to-end rocking movement of a pallet of parts to further enhance film build consistency. Passing through three post-electrocoating rinse tanks later, parts are inducted into an overhead oven where they are cured to a high-quality, corrosion-resistant finish.