METHOD AND APPARATUS FOR CLEANING PRINTING CYLINDER AND CORRESPONDING DIP ROLLER IN PRINTING MACHINE

PROBLEM TO BE SOLVED: To reduce the adhesion of a quick drying medium to a form roller and a plate cylinder by drying by spraying a cleaning fluid to a plate cylinder when a liquid medium is supplied to the plate cylinder by the form roller during printing operation and spraying the same to the form roller and the plate cylinder during non-printing operation to suck up the cleaning fluid from the peripheral surfaces of them. SOLUTION: Lacquer is supplied to a form roller 3 from a lacquer supply device 4 during printing operation and transferred to the plate cylinder 2 in a state requlated in quantity and, during a period when the plate cylinder 2 guides lacquer, a cleaning fluid is sprayed on the plate cylinder 2 in the state controlled by predetermined pulses by a sprayer 10 to be sucked up by a sucking-up layer 11. During non-printing operation, the plate cylinder 2 is decoupled from the form roller 3 and the cleaning fluid is sprayed on the plate cylinder 2 and the form roller 3 in the same way by the sprayer 10 and continuously sucked up from the peripheral surfaces of the plate cylinder 2 and the form roller 3. Therefore, the plate cylinder 2 to which a printing plate is provided under tension and the form roller 3 can be washed in combination and the form roller 3 and the plate cylinder 2 can be automatically washed within a printing press in different operation states and a cleaning time can be shortened.