Abstract: Calender for treating web materials, comprising a structure for supporting two heated rollers forming a nip, wherein each roller has surface reliefs (RR) and in an operational setting of the calender the reliefs of one roller are radially opposed to those of the other roller, each roller rotates with a predetermined angular speed around its axis, the rollers are heated by heating means, and each roller undergoes an axial elongation as a consequence of its heating. The calender comprises detection means (E1, E2; IS) adapted to detect the axial elongation of each roller and a programmable control unit (UCP) connected to the detection means and to the heating means. The control unit is programmed to determine the difference between the axial elongations of the rollers and emitting an alarm signal if the absolute value of this difference is greater than a limit value.

Abstract: A calender for the treatment of web-like materials, including a fixed structure adapted to support two heated rollers shaped to be connected to the fixed structure, to a drive unit and to a heating system. The calender includes automatic elements for engaging and respectively for disengaging the rollers to and from the fixed structure, the drive unit and the heating system; the automatic elements are controlled by a programmable control unit and each of the rollers has an engaging surface shaped to be engaged by mechanical elements for moving the rollers which move the rollers between the calender and one or more waiting or parking stations while the rollers are at a temperature between 50° C. and 200° C.

Abstract: A calender for the treatment of web-like materials, including a fixed structure adapted to support two heated rollers shaped to be connected to the fixed structure, to a drive unit and to a heating system. The calender includes automatic elements for engaging and respectively for disengaging the rollers to and from the fixed structure, the drive unit and the heating system; the automatic elements are controlled by a programmable control unit and each of the rollers has an engaging surface shaped to be engaged by mechanical elements for moving the rollers which move the rollers between the calender and one or more waiting or parking stations while the rollers are at a temperature between 50° C. and 200° C.

Abstract: Calender for the treatment of web-like materials, including a fixed structure supporting two heated rollers reciprocally arranged so as to form a nip traversable by web-like materials, where each roller has pins mounted on bearings. The structure includes two lower levers and two upper levers adapted for exerting on the bearings forces oriented according to not coinciding directions, each lever being connected with an actuator that controls its rotation around a horizontal axis to put it in a first engagement position of the respective bearing and in a second release position, such that in the second position of the levers the extraction of the rollers from the calender is allowed.