| 摘要 |
PROBLEM TO BE SOLVED: To prevent an ink from leaking through the rear end side or side of a stencil base paper installed on a small-diameter plate cylinder. SOLUTION: The peripheral wall 2 of the plate cylinder 4 has an ink passing region and a non-passing region. An ink screening member 30 is arranged at the rear of a printing region with respect to the rotating direction R of the plate cylinder 4. The ink screening member 30 consists of a near saw-teeth-like basic material 31 and an elastic covering member 32 bonded with each other. Spaces 36 are formed between both the members. A portion covered by the ink screening member 30 has large- diameter openings 28 or a larger open area ratio, while a portion not covered has small-diameter openings 18 or a smaller open area ratio. At printing, an ink moves on the outer peripheral surface of the plate cylinder 4 towards the counter direction of the arrow R and enters the spaces 36. The covering member 32 deflects by being pressed with a press roller, resulting in returning the ink in the space 36 through the opening part 28 into the plate cylinder 4. As compared with the amount of the ink going out of the interior of the plate cylinder 4, the amount of the ink pushing back through the openings 28 covered by the ink screening member 30 is larger. Thus, no ink leaks to the outer peripheral surface side of the ink screening member 30. When the press roller separates from the covering member, the volume of the space 36 returns to its initial volume.
|
