| 摘要 |
PURPOSE:To enable exact avoidance of possible leakage of printing ink by making the opening rate of the circumferential wall of a plate cylinder having tiny holes thereon smaller than that at the central area. CONSTITUTION:A plate cylinder 1 has a three-layer structure which comprises a support cylinder 2, an intermediate screen layer body 4 and an outer screen layer body 5 wrapped entirely on the outer surface of the intermediate screen layer 4 except for the mounting part of a land member 3. The support cylinder 2 has numerous tiny holes 6 for passage of ink on the part excluding the mounting part of the land member 3, the perimeter thereof and both side ends of the cylinder. The circumferential wall thereof having the tiny holes 6, namely, an ink passage area 7 has a porous structure with the mesh of about 20-60. The tiny holes 6 are so arranged as to be 20-5%, for instance in the opening rate at the central area A except for the peripheral part and 0.5-0.05% in the minimum opening rate at the peripheral part, namely, at the final end B1, the initial end B2 and both side ends B3 of the ink passage area 7 except the central area A in the ink passage area 7. |
