Paper mill roller coatings

Paper and pulp plants use hundreds of rollers of different functions in their production lines: press rollers (for water removal from pulp), guide rollers (paper direction in formation), drying rollers (thermal transfer), calendaring rollers (finishing and thickness), winding rollers (winding of the final product), coating rollers (application of coatings on paper). Cast PU coatings increasingly replace natural and synthetic rubber in these applications due to their combination of: greater durability (2-5x rubber service life), better chemical resistance (compatibility with severe process chemicals — bleaching), greater dimensional precision (tighter tolerances), better cut and abrasion resistance (production with recovered paper frequently includes metallic impurities that damage rollers). PPDI prepolymers (para-phenylene diisocyanate) are reference technology in this application — greater thermal and dynamic resistance than conventional TDI systems. Specialized market with high added value, dominated by global PU prepolymer manufacturers (Covestro, Lanxess, Era Polymers).