Rapid heating and cooling of a rotating calender roll involves flame or radiation heating of thin metal sheet on an insulated roll body before the processing gap then rapid cooling behind the gap

摘要

The temperature of a metal sheet(14), preferably copper sheet, covering the surface of a calender roll body(9) is locally raised(5) to a plastic processing range by radiation heating or heating with a flame. Low thermal conductivity of a roll cover retains the temperature until the heated area has rotated past the gap(20) between the roll(1) and an opposing roll(2). Fluid or gas coolant then cools(6) the heated metal sheet area to the solidify the plastic and the latter separates from the roll which is then reheated. An Independent claim is included for a calender roll construction used in the process which comprises a roll body with a cover comprising an insulating layer of heat resistant friction material with low thermal conductivity onto which a thin outer metal layer for producing textures or structures is electroformed or bonded.