Autodeposition is a waterborne, anticorrosive paint layer applied to metal by means of a chemical reaction rather than by electrical or contact methods. The autodeposition process is simple in comparison to other processes used for applying corrosion-resistant coatings. Following conventional cleaning and rinsing stages, metal parts are immersed in a coating chemical bath, where the pigment and resin particles are deposited. The growth in film thickness is time-dependent. A rapid deposition rate is followed by a decrease in growth, which results in a uniform and 'self-limiting' coating thickness. A protective barrier film is formed wherever the coating bath makes contact with the metal workpiece. This process is faster and more environmentally responsible than conventional coating processes; however, a typical seven-stage autodeposition process still requires several cleaning stages. Recent advances are pushing autodeposition technology past this boundary to offer manufacturers and coaters a coating solution that lowers the environmental impact even further, while also reducing the overall manufacturing production footprint and increasing efficiency in the assembly process. The newest development in autodeposition coatings allows manufacturers to eliminate several layers of cost and complexity. It also has the ability to coat large volumes of densely racked or complex shaped metal parts uniformly, giving finishing professionals the choice to coat their parts as an assembly or as individual pieces. Advanced autodeposition coatings allow for the opportunity to coat many or a few parts in a single coating bath without requiting adjustments to process conditions or equipment. The coatings also offer the opportunity to design combined primer-topcoat systems that reduce the effective paint line footprint by up to 50% compared to conventional coating systems. These and other advances are allowing autodeposition coating processes to reduce environmental impact, improve the functional performance of the part and lower total manufacturing costs in automotive paint shops and other applications. The technology already is being used in automotive manufacturing facilities to displace conventional metal pretreatment and electrocoat processes for coating entire vehicle frames. Global research in the automotive industry and at universities is expanding the opportunities for autodeposition coatings even further. Improvements under investigation include reducing cure time/temperature through polymer research, enabling multimetal substrate coating applications, and enhancing surface appearance on all substrates.
Streamlining autodeposition
Finishing Today ; 84 , 5 ; 14-17
2008
4 Seiten, 2 Bilder
Aufsatz (Zeitschrift)
Englisch
Kraftfahrwesen | 1989
|SAE Technical Papers | 1989
|Autodeposition Coatings: New Commercial Applications
SAE Technical Papers | 2008
|Autodeposition; An Environmentally Sound, Quality Finish
SAE Technical Papers | 1997
|Autodeposition; An Environmentally Sound, Quality Finish
British Library Conference Proceedings | 1997
|