Integrated Process (Powder Slurry)

The integrated process is commercially used on the Mercedes Benz "A Class" car. This environmentally friendly coating system was cooperatively developed by BASF, Mercedes Benz and equipment supplier Duerr at the automotive manufacturer's plant in Rastatt, Germany, that progressed from vision to reality in just two years. One of the system's components is a powder slurry clearcoat. Powder slurry is basically a powder coating, which is more environmentally friendly than solvent-based coating, in a liquid form. And the liquid material used is water rather than solvent. In fact, all primer and topcoat components used in the process are waterborne.Also, components of a typical coating system are applied and baked on for adhesion individually. The application system developed for the Mercedes A-class at Rastatt is a "wet-on-wet-on-wet" process that removes a baking step, thus supporting another environmental goal. Furthermore, the powder slurry clearcoat process can be applied on conventional paint lines after a relatively small capital expenditure. This leading edge approach was honored with multiple awards and international recognition.Specifically, following immersion in the corrosion-preventing dip coating that is free of any heavy metals, car bodies are coated with two waterborne basecoat layers, the first of which assumes the function of a primer-surfacer. The second waterborne coating layer delivers the actual color position. The final coat is a clearcoat applied by the powder slurry process. No energy-intensive drying is required because all three layers are applied wet-on-wet-on-wet. To assure a perfect color match, plastic components are affixed to the body before applying the topcoat and coated at the same time. Using new paint materials and applications systems that do not sacrifice quality, a massive reduction in energy usage and emissions, as well as trim coatings consumption, was acheived by 20 percent.