System for keeping calender rolls of a paper machine clean

A system for maintaining calender rolls of a paper machine clean, including in a running direction, that is in the MD direction, of the web (W) after a dryer section (1) a coating station (2), an additional dryer section (3), a measuring station (4) and a calender (5), which is advantageously a multi-nip On-Line calender, before a reeling unit (6), when producing high-gloss paper or coated paper, characterized in that in order to prevent coating dye from addhesing onto a smooth surface of the calender roll and as a result, the smooth surface of the calender roll from becoming soiled and to prevent an overheating phenomenon and an extra heat-transfer resistance of a thermoroll, the system includes a second measurement station (10), which is provided with measuring and indicator means for producing an output indicating the soiledness of the web (W) or a humidity profile in transverse direction, that is in CD direction, and that, when the output of the second measurement station (10) indicates excessive soiledness or uneven humidity profile, the system will perform as a response to the output of the second measurement station (10) a function selected from a group including:

• cleaning of the surface of the smooth-surfaced calender roll;
• a change of nip load in the calender (5);
• correction adjustment of the CD-directional humidity profile of the web (W);
• cutting of the web (W) and conducting it into a pulper, and/or a change of running speed of the web (W).