| 摘要 |
A method for controlling the temperature of a heated roll in a calender is provided. The calender comprises at least one heated roll or thermoroll and at least one backing roll, between which is formed a nip through which the material web is conveyed. To the heated roll is supplied internal thermal power by internal heating means of the roll, and external thermal power by external heating means of the roll. Before changing the heated roll, internal thermal power is minimized within a specific period by control means provided in conjunction with the internal heating means; external thermal power is maximized within a specific period by control means provided in conjunction with the external heating means; and the surface temperature of and/or the thermal power released by the heated roll, which corresponds to the surface temperature and/or thermal power desired for the grade of the material web, is maintained within a specific period. The present invention further provides a method for changing the material web grade to another grade.
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