Patent ID: 6827010
Filing Date: 2004-12-07
Classification: D21G

Abstract:
A multi-roll calender and a fibrous web traversing said multi-roll calender, which multi-roll calender is an on- or off-line multi-roll calender comprising separate first and second sets of rolls, each set of rolls comprising rigid-shell press rolls and resilient-shell backing rolls for the press rolls, placed alternately one after the other, successive nips being situated between the press rolls and the backing rolls placed against each other, as well as a reversing or guide member guiding the run of the fibrous web so that as the fibrous web extends from each press roll to each reversing or guide member, the web leaves a surface defined by either a press roll or a backing roll while traveling between successive nips, wherein in the on- or off-line multi-roll calender comprising two sets of rolls the fibrous web extends past an intermediate moistening means after a first set of rolls, and before the second set of rolls, and that in the calender:a pre-moistening means immediately precedes the first set of rolls, and wherein the fibrous web enters the first set of rolls having a moisture content which is higher than the fibrous web moisture content immediately before the pre-moistening means; the fibrous web has a moisture content which is lower immediately after the first set of rolls; after the first set of rolls and the intermediate moistening means, the fibrous web has a moisture content which is higher than the moisture content of the fibrous web immediately before the intermediate moistening means; and the fibrous web after the second set of rolls has a moisture level lower than the moisture level of the fibrous web before the second set of rolls.