Calender, to polish paper/cardboard webs, has a wide nip between a roller and a mantle, with a heater aligned at the roller surface to prevent flash evaporation at the exit from the nip

摘要

The calender (1), to polish the surfaces of paper or cardboard webs (2), has a wide nip (3) formed by a roller (4) and a mantle (5) with an inner support shoe (6). An induction heater (13) is aligned at the roller surface. The roller has a thermally insulated core (9) with a thin outer layer (10) which is thermally conductive and has a low heat capacity, and a thermal coefficient of expansion which gives a width change through heat of at most1.3% under working conditions.