Multi-roll calendar

摘要

The multiroll calendar comprises a roll stack, in which two consecutive rolls form a roller nip for calendaring wood free coated paper on a brightness according to Gardner of greater than 75% or natural gravure papers on a pps-10 S-roughness under 1.15 mu m or film-coated light-weight coated papers on a brightness according to Gardner over 55%, where the roll stack is structured in a following row sequence such as a hard controlled deflection top roller (2), an elastic center roller with a thin metallic surface layer, a heatable hard middle roller, and two elastic middle rollers. The multiroll calendar comprises a roll stack, in which two consecutive rolls form a roller nip for calendaring wood free coated paper on a brightness according to Gardner of greater than 75% or natural gravure papers on a pps-10 S-roughness under 1.15 mu m or film-coated light-weight coated papers on a brightness according to Gardner over 55%, where the roll stack is structured in a following row sequence such as a hard controlled deflection top roller (2), an elastic center roller with a thin metallic surface layer, a heatable hard middle roller, two elastic middle rollers with a thin metallic surface layer, a heatable hard middle roller, an elastic middle roller with a thin metallic surface layer and a hard controlled deflection bottom roller. The elastic roller with a metal surface layer in the calendaring operation has a surface temperature of 90-130? oC. A line load of 300 N/mm acts in the roller nip in order to receive a nip length in web direction of 10 mm. A pressure element (14) is provided, in which the paper web (11) is designed before or after the roller nip over a contact angle of 5[deg] on the surface of a smooth, hard and heated roller. An independent claim is included for a method for converting multi-roll calendars.