There are two commercial multi-roll

There are two commercial multi-roll calenders available: Valmet’ OptiLoad and Voith Sulzer Paper Technology’ Janus calender. Both units are targeted at new installations on- and off-machine, as well as for rebuilds of existing supercalenders. Voith’ system was commercialized first, starting with the October 1996 startup of two units at KNP Leykam’ Maastricht, Netherlands, mill. Valmet’ first two off-machine OptiLoad units were brought online in April 1997 on the huge 354-in.-wide (9-m) coated woodfree line at Metsa-Serla’ Oulu, Finland, mill. Most installations are off-machine, but the long-term potential of these units appears to include wider on-machine application. Two Janus calenders are operating on-machine, at Lang Paper in Germany on SC grades, and for an off-machine coater in Japan. Valmet’ first on-machine units will start up in 1998; the first in Canada, followed by one in Finland.