Characterization of Calender Roll Surface Features Using Interferometric Profiling, 1995 Finishing and Converting Conference Proceedings

J.K. Knapp

R.D. Lampman

Praxair Surface Technologies

Sheet surface features, such as smoothness and gloss, are greatly influenced by calender roll surface topography. It is known that calender roll surfaces replicate onto the paper being processed. Industry standards utilize analytical tools, such as profilometry, to characterize roll topography and identify wear and defects in the roll face. This practice is an important aspect of maintaining consistent high quality paper. This report goes beyond the use of such standardized methods and examines the use of interferometric profilometry as applied to the measurement of calender roll surface degradation.

An optical, non-contact profiling technique based on interferometric analysis is used to generate three- dimensional surface profile measurements of two calender roll materials. The ablility of interferometric profilometry to detect slight surface degradation of a thermal spray coating and chrome cast iron, following exposure to abrasive wear and corrosion, was investigated. This information is used to elucidate the mechanism of calender roll wear as well as provide a means of gauging the degree of surface finish degradation.