Water treatment plays a crucial role in automotive painting lines, impacting both the quality of the paint application and the longevity of the painting equipment. 

  • Water Quality: The preparation stage before painting an automobile or truck involves water-based cleaning processes to remove dirt, oils, and other contaminants from the surface. The quality of the water used is vital because impurities in the water can lead to poor paint adhesion and defects in the paint finish such as spotting or blushing.
  • Biofilm Formation: Biofilms are colonies of microorganisms that adhere to the surfaces of water distribution systems. In an automotive paint line, biofilms can develop in the piping and tanks that distribute and store process water.
  • Impact on Paint Quality: The presence of biofilms can lead to the introduction of bacteria and other contaminants into the paint and onto the car’s surface, which can cause defects in the paint such as fisheyes, pinholes, and craters.
  • Maintenance and Downtime: Biofilms can also lead to blockages in the water system and nozzles, requiring costly maintenance and potential downtime of the painting line to address these issues. 
  • Corrosion Protection: Historically, Chromium(VI) compounds were added to water systems in automotive paint lines for their excellent corrosion inhibition properties. They help protect the metal surfaces and equipment from corrosion, which is particularly crucial in the highly controlled environment of paint shops.
  • Now, without Chromium(VI), alternative corrosion inhibitors must be used, which may not be as effective or might require higher concentrations or more frequent applications. This can increase the operational costs and complexity of water treatment systems. 
  • Innovative physical treatment technologies such as ultrasound, the use of catalysts and biosignal technology are employed to ensure the purity of water used in the painting process. They offer an environmentally friendly solution against surface contamination, corrosion and improve the homogeneity of paints.