| 摘要 |
PROBLEM TO BE SOLVED: To perform a direct forming and repeated erasings of a printing image area by providing a smooth surface without pores, which has a specified surface roughness, on a printing plate, and making the surface hydrophilic or hydrophilizable, and at the same time, preventing the surface from containing a strong dipole. SOLUTION: A device which erases a printing image area and hydrophilizes a printing form plate is provided in a printing mechanism, and is attached to the periphery of a plate cylinder 1 equipped with the printing form plate 2 on which the printing image area is formed. Also, on the plate cylinder 1, a rubber cylinder 3 is provided together with respective rollers 4 and 5 for an ink device or a dampening device. In addition, on the printing plate 2, a cleaning device 6 and a dryer 7 are provided in a manner to be able to approach/separate, and a cleaning fleece 8 is fed from a feeding roller 9 to a pressing roller 10, and is pressed to the printing plate 2. In such a constitution, on the printing plate 2, a smooth surface without pores, of which the surface roughness Ra satisfies Ra<1μm, is provided. Then, the surface is made hydrophilic or hydrophilizable, and at the same time, the surface does not contain a strong dipole. |
