| 摘要 |
PURPOSE:To minimize the fluctuation of the density of printing by preventing the defect in ink-transfer due to the dew condensation on the surface of a roller, by a method wherein a cooling roller is opposedly provided in contact with inking rollers and the cooling control of a plate surface is carried out by controlling the amount of water or the temperature of water according to the speed of operation. CONSTITUTION:A printing press consists of a plate cylinder 1, a blanket cylinder 2, inking rollers 3a-3d, reciprocating rollers 4a, 4b, an inking roller group 5, a cooling roller 8, a chilling unit 9, a flow rate control valve 10, and flow rate control apparatus 11. The cooling roller 8 is made double cylindrical. The outer cylinder rotates induced by the rotation of the inking rollers and cooling water flows through the space between the inner cylinder and the outer cylinder. The cooling roller 8 is connected to a cooling water piping with a rotary joint or the like. In stopping operation, the flow rate control valve 10 is tuned ON by the command from the control apparatus 11 and the dew condensation on the surface of the cooling roller 8 is prevented. Together with the start of the operation of the printing press, the temperature of a plate surface is detected and the flow rate is controlled by the flow ate control valve 10.
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