Calender for treating a web of paper

摘要

A calender for treating a web of paper includes a stack of hard rollers and soft rollers. The stack includes a first set of processing nips and a second set of processing nips. Each processing nip is formed by a juncture of one of the hard rollers and one of the soft rollers. One side of the web of paper contacts against the hard rollers in the first set of processing nips and contacts against the soft rollers in the second set of processing nips. At least a last soft roller in the stack, which delimits a last processing nip that the web of paper passes through in the calender, has a lower surface roughness Ra than a surface roughness Ra of at least a first soft roller in the stack. The first soft roller delimits a first processing nip that the web of paper passes through in the calender. The surface roughness R. of the last soft roller is less than 0.35 mu m.