Three-dimensional scanning electron microscopy characterization of the topography of textured polymeric surfaces

A stereographic scanning electron microscopy (SEM) technique combined with a filtering procedure was used to characterize the surface topography of injection- molded polymeric plaques to improve the understanding of the relation between surface texture and gloss of deliberately textured and quite rough surfaces. The specimens, having small differences in surface topography and gloss, were produced by using two mold cavities with slight differences in surface texture and three different polymers. Small differences in gloss were also achieved by changing the processing conditions. All specimens exhibited a very low gloss. A stereographic image of the textured surface was constructed from two SEM micrographs of the same area, but differing slightly in viewing angle. From this image, descriptors characterizing the surface topography could be evaluated, in the present study the root-mean-square roughness and a lateral correlation length. The results indicated that small differences in gloss in the low gloss region could to a significant extent be associated with small-scale variations in the surface topography. The EM method used might provide a useful tool for identifying the length scale at which the surface pattern or irregularities has a strong effect on the appearance of polymeric low-gloss surfaces. \ua9 2010 Society of Plastics Engineers