Colorkey Powder Primer: Effect of Cure Time and Temperature on Finish Appearance and Adhesion

摘要

The automotive industry has made an effort to reduce the environmental burden of vehicle manufacturing processes. In particular, efforts have been directed toward coating processes, known for their major environmental impacts, as compared to other vehicle manufacturing stages. The use of powder coatings is seen as an alternative to solvent-borne counterparts, due to their minimal or zero VOC emissions. However, powders have mostly found application as anti-chip primers and their use as topcoats has not yet become a standard process. An important innovation is the use of colorkey primers for areas of the car that do not require high glossy appearance. Colorkey primers, if properly formulated and applied, could potentially eliminate the basecoat stage in these areas. This would result in significant reductions in material use, and process effort. The research discussed in this paper studied the finish quality of one powder colorkey primer (red) and two powder basecoats (red and black) in relation to the cure temperature and time. Curing scenarios were investigated corresponding to the cure of the cure window. Appearance parameters such as gloss, distinctness of image (DOI), and orange peel were compared for each curing condition and powder type. In addition, final film build and adhesion properties were determined.