Milling process optimization for the best surface coat adhesion of the rigid polyurethane foam

Abstract

Abstract In this research, the influences of milling parameters on the surface quality and coat adhesion of rigid polyurethane (PU) foam are highlighted. Several surface texture parameters were correlated with the milling parameters. The correlation between the coat adhesion strength, as determined by the pull-off test, and the milling parameters was also established. The investigation revealed that traditional height distribution roughness parameters, such as Ra, Sa, Rz, and Sz, do not offer sufficient information for a proper surface adhesion evaluation. Shaping and bearing surface parameters, on the contrary, provide more information for the surface quality assessment, although the structure of the PU was found to be inhomogeneous. The evaluation of milling process effects on surface texture and coat adhesion and the determination of optimal machining conditions were derived based on response surface methodology. The goal was an adequate surface texture that provides the best coat adhesion strength.