| 摘要 |
A calender in a paper or board machine comprises a calender frame, at least two soft-faced rolls mounted on the calender frame and at least one hard roll mounted on the calender frame in a manner that allows the hard roll to be displaced between a first position in which it forms calendering nips with the two soft-faced rolls and a second position in which it is spaced from the soft-faced rolls. During threading of the web; while the calender is in operation, the hard roll is shifted to its second position, the web is passed over the soft-faced rolls, and the hard roll is shifted back to its first position and brings the web into the nips between the hard roll and the soft-faced rolls. |
