摘要 |
The present invention discloses a planographic printing plate having a notched portion on its surface having a required size, and having smaller burrs at a rear face, and a planographic printing plate cutting device and a planographic printing plate cutting method for forming such a planographic printing plate by cutting. The planographic printing plate cutting device of the present invention includes an upper roller for forming a recessed section at the planographic printing plate. The upper roller, which is formed substantially into a disc shape as a whole, has a pressing portion parallel to a web (the planographic printing plate), and a slope portion that is slanted with respect to the surface of the web at a predetermined inclination. This upper roller presses the web such that a sloped face (recessed section) that is slanted with respect to the surface of the web is formed. Next, a shearing roller shears the web at the sloped face such that a remaining portion of the sloped face forms a notched portion. Because formation of the notched portion and the shearing process are carried out as separate processes by separate members, a notched portion having a required size can be formed at the surface, and burrs at the rear face can be reduced.
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