DOI: 10.5176/2251-3701_2.2.70
Authors: Cathren E. Gowenlock, Ian Mabbett and David A. Worsley
Abstract:
Near Infrared (NIR) radiative curing is a fast thermal curing technology used to cure 25 micron polyester melamine industrial coil coatings on galvanized steel substrate. The cure is optimized when the top coat is relatively transparent to NIR and with most NIR absorption taking place at the substrate surface. In this study UV/Vis/NIR spectroscopy and lab scale curing trials with a white top coat were used to show that absorption in the bottom most layers of the coating system can be taken a stage further by the addition of NIR absorbing pigment to the primer layer. The results show energy efficiency benefits for NIR cure by increasing the amount of incident radiation absorbed without altering the colour properties of the coating. A similar smaller benefit is also evident with a conventional convection cure.
Keywords: Coil coating, fast cure, melamine, Near Infrared, polyester
