PRELIMINARY GRINDING METHOD OF METAL PLATE FOR LITHOGRAPHY PLATE, AND PRELIMINARY GRINDING APPARATUS OF METAL PLATE FOR LITHOGRAPHY PLATE

摘要

PROBLEM TO BE SOLVED: To provide a preliminary grinding method and a preliminary grinding apparatus causing no uneven grinding on a metal plate for lithography plate even if the grinding is carried out for a long time. SOLUTION: The surface of the metal plate for printing plate is brought into contact with a rotating grinding roller. Non-woven fabric of the grinding roller contains abrasive material to polish the surface of the metal plate for printing plate. The grinding roller is constituted of first annular bodies 26A formed of non-woven fabric containing abrasives, and second annular bodies 26B having smaller diameters than that of the first annular bodies 26A and harder than the first annular bodies 26A with the first and second annular bodies laminated on a core material 24.