ON-LINE MULTI-ROLL CALENDER AND A METHOD FOR CALENDERING FIBROUS WEB ON AN ON-LINE MULTI-ROLL CALENDER

摘要

An on-line multi-roll calender (10) comprises: as intermediate rolls with a hard surface, forged steel thermo rolls (T); as intermediate rolls with a soft surface, polymer rolls (C) for which there is a system for balancing their temperature; for guiding the web (W) in each nip (Nl...N7) and out of it, at least one fly roll (F) provided with a flexible one-piece composite shell (54); web break detection means; a web arranged extra wide so that, during run, the web is wider than an end area of a shell of the hot thermo roll (T) of which a considerable amount of heat can be conducted or emitted into a cover (42) of the adjacent polymer roll (C); first actuators (100) and first mechanisms (101) for transferring the polymer roll (C, 13) during run sideways (RO) in relation to the press plane of the roll stack; and second actuators and second mechanisms for increasing or decreasing (WS) the distance of a fly roll (F) with a composite shell from the adjacent thermo roll during run so that the length of the web (W) in the roll stack changes accordingly. Furthermore is described a method for calendering a fibrous web on an on-line multi-roll calender.