| 摘要 |
When a cylinder 14 of a printing unit having superimposed double printing elements 1, 2 working on the rubber-on-rubber principle functions only as an impression cylinder (ie. the forme cylinder 12 and cooperating blanket cylinder 14 are inoperative for printing) there is a tendency to contamination with ink and paper dust. This is reduced by giving the transfer cylinder 14 an ink-repellent coating. The coating may be in the form of a metal or plastics foil clamped above the normal rubber blanket, or may be evaporated onto the blanket as a Cr or Ni layer; the coating is hydrophilic in all cases. <IMAGE> |
