Washing device and its method for impression cylinder jacket in sheet-fed offset two-sided printing press

A washing device for an impression cylinder jacket in a sheet-fed offset two-sided printing press equipped with an impression cylinder installed with a jacket having a flexible metal plate, a base layer formed to have concave-convex profile on the surface of said metal plate and a low surface energy resin layer formed on said base layer, comprising:

• a cleaning unit capable of being in contact with or separated from a blanket cylinder that opposes said impression cylinder;
• a water dampening unit equipped with a water form roller capable of being in contact with or separated from a plate cylinder that opposes said blanket cylinder and supplying water to said plate cylinder;
• an inking unit equipped with an ink form roller capable of being in contact with or separated from said plate cylinder and supplying ink to said plate cylinder;
• and
• a controller that executes a first control of causing said plate cylinder to contact with said blanket cylinder and said blanket cylinder to contact with said impression cylinder, and causes each cylinder to rotate under those contacts for a specified period of time while said cleaning unit is in contact with said blanket cylinder;
• and a second control of separating said plate cylinder from said blanket cylinder, and causing said water form roller and said ink form roller with said plate cylinder.