Patent ID: 6848357

Claim:
A method of cooling a heated roll in a calender having a nip formed between the heated roll and an adjacent backing roll, the nip being adapted to have a material web conveyed therethrough, the heated roll having a mantle with an external surface adapted to contact the web in the nip, the external surface being heated by thermal energy from an internal heating device disposed within the heated roll and thermal energy from an external heating device disposed outwardly thereof, the internal and external heating devices cooperating to control the external surface at a process temperature for producing a corresponding grade of the web, said method comprising: decreasing the thermal energy provided to the external surface by the internal heating device; increasing the thermal energy provided to the external surface by the external heating device as necessary to maintain the external surface at the process temperature; minimizing the thermal energy provided to the external surface by the external heating device, after the thermal energy provided by the internal heating device is decreased to a minimum level, so as to cool the external surface, thereby allowing the grade of the web to be produced until the thermal energy provided by the internal heating device is decreased to the minimum level.