Patent ID: 8302558

Claim:
An apparatus for coating a cylinder with a plastic composition comprising: supporting means for horizontally mounting a cylinder (C) for rotation about its axis of rotation; a coating unit disposed on one side of the cylinder for selectively applying a layer of heat-hardenable plastic composition onto the surface of the cylinder (C) ; driving means for rotating the cylinder (C) in a direction to cause its peripheral surface to move past said coating unit; heating means for applying radiant heat to said cylinder (C) throughout its length as said cylinder is rotated, said heating means including a plurality of discrete heating elements distributed along the length of the cylinder and around at least part of the peripheral surface of the cylinder (C), said heating elements being arranged at least in separate columns disposed parallel to one another along the length of the cylinder ; a temperature sensing system for measuring the surface temperature of the cylinder (C) along the whole length of the cylinder; and a processing unit coupled to the temperature sensing system for controlling operation of said heating elements as a function of the measured surface temperature and a desired temperature setting (t c ), wherein said temperature sensing system is adapted to output a temperature measurement profile (T m ) representative of the surface temperature of the cylinder measured along the whole length of the cylinder, which temperature measurement profile (T m ) comprises a plurality of measurement samples taken along the length of the cylinder (C), said temperature measurement profile being subdivided into a plurality of zones (Z 1 to Z 8 ) each associated to one corresponding column of heating elements, each zone (Z 1 to Z 8 ) encompassing a corresponding series of measurement samples, and wherein the processing unit is adapted to control operation of each column of heating elements on the basis of the surface temperature measured within at least one of said zones (Z 1 to Z 8 ).