At the recent European Automotive Coating Conference held in Bonn, Germany, Sven Radek, Group Leader for Process and Application for Axalta Coating Systems (NYSE: AXTA) examined the challenges and opportunities that lightweight automotive design brings to coatings systems used by car manufacturers (OEMs).
"Lightweight vehicle construction is definitely driving innovation in low-bake coatings,” Radek said. "Over the next 15 years, automotive manufacturers will be replacing standard steel with high-performance steel, aluminium, plastics and composites. They will also be cutting weight from safety, communication and electrical components, in an effort to make vehicles lighter to reduce emissions and fuel consumption. These changes will have a significant impact on coating systems, as many of the new, lighter materials cannot withstand high-bake temperatures.”
Radek referenced the research that Axalta, a leading global manufacturer of liquid and powder coatings, is conducting on new technologies that hold the promise of integrating existing low-temperature paint system solutions. To date, no comprehensive, integrated solution exists that suits all application situations.
Axalta already has low-bake systems that cure faster and at lower oven temperatures than traditional systems, to help car manufacturers reduce energy costs and enable them to use new materials. The company also has an active development programme for low-temperature topcoats and electrodeposition coats, as well as for two coat (2K) fillers, 2K PUR waterborne basecoats and 2K clearcoats that can cure at 80°C. With sustainability and productivity at their core, many of Axalta’s new systems share the ability to reduce the number of bake steps while aiming to deliver the same full layer performance as traditional coating processes.
Radek explained the existing low-temperature paint systems available for plastic automotive parts, for trucks and buses, as well as for specialised colours for customised OEMs that cure at between 80°C and 125°C. He also examined the benefits and disadvantages of different technologies that allow curing at lower temperatures ranging from 70°C to 120°C.
Finally, Radek presented possible process options for the future. One scenario that is becoming popular again is UV drying on the paint line. Axalta’s UV Monocure System, one of the company’s Harmonized Coating Technologies, replaces drying ovens with UV curing. This can reduce the drying zone footprint by as much as 70%. He also discussed how new robotic application will open up the possibility of reaching so-called shadow zones – those that are very hard to reach during the coating process.