Apparatus for coating a cylinder, in particular a wiping cylinder of an intaglio printing press

Abstract

There is described an apparatus () for coating a cylinder (C), in particular a wiping cylinder of an intaglio printing press, with a plastic composition comprising inter alia heating means () for applying radiant heat to the cylinder throughout its length as the cylinder is rotated, the 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, the heating elements being arranged at least in separate columns (toO) disposed parallel to one another along the length of the cylinder. The apparatus further comprises a temperature sensing system () for measuring the surface temperature of the cylinder along the length of the cylinder and a processing unit coupled to the temperature sensing system () for controlling operation of the heating elements () as a function of the measured surface temperature and a desired temperature setting (t). The temperature sensing system () is adapted to output a temperature measurement profile (T) representative of the surface temperature of the cylinder measured along the length of the cylinder, the temperature measurement profile being subdivided into a plurality of zones (Zto Z) each associated to one corresponding column of heating elements (toO). Operation of each column of heating elements (toO) is controlled by the processing unit on the basis of the surface temperature measured within at least one of the zones (Zto Z).