Gloss Retention of Calender Roll Thermal Spray Coatings Abraded by TIO2 Slurries, 1998 Finishing and Converting Conference Proceedings

A laboratory study was undertaken in which polished high gloss thermal spray coatings were abraded by use of titanium dioxide slurries. A two level factorial design with blocking was used to study the effects of load, weight percent TiO2 solids, time and pH on gloss. Light microscopy, scanning electron microscopy and vertical scanning interferometry were used to evaluate surface structure and texture of the as-polished and abraded surfaces.

It was found that only time and pH produced a significant change in gloss. The effect of material type was not clearly differentiated on a statistical basis. A Super D-Gun TM tungsten carbide coating showed the best retention of gloss but was not significantly better than cast iron, contrary to behavior already established on many calender lines. The SDGTM coating did undergo substantially (statisticaLly significant) less surface roughening than cast iron. Two ID-OF thermal spray coatings did not retain as high gloss numbers as cast iron but did have smoother surfaces. These latter observations, however, were not always statistically significant.