Patent ID: 7147754

Claim:
A system for maintaining calender rolls of a paper machine clean when producing high-gloss paper or coated paper, the system comprising: a dryer section; a coating station; an additional dryer section; a first measuring station; a multi-nip on-line calender having a plurality of calender rolls; a reeling unit, a web passing from the dryer section to the coating station to the additional dryer section, to the first measuring station, to the calender, and then to the reeling unit; a second measurement station positioned to receive the web after the coating station but before the calender, which is provided with measuring and indicator means for producing an output indicating the soiledness of the web or a humidity profile in a CD direction, the second measurement station arranged to output an indicator of excessive soiledness or uneven humidity profile; an apparatus responsive to an output of the second measurement station indicative of excessive soiledness, or uneven humidity profile said apparatus having a configuration and structure sufficient to perform at least one function selected from a group consisting of: cleaning of the surface of the smooth-surfaced calender roll; changing the nip load in the calender; making a correction adjustment of the CD-directional humidity profile of the web; cutting the web and conducting it into a pulper; and changing the running speed of the web.