| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for surface treating an aluminum plate for a printing plate to uniformly form grains of predetermined roughness economically and efficiently. SOLUTION: An electric energy monitor 32 monitors a driving electric energy of a rotary polishing brush 17, and outputs a level signal responsive to the energy to a controller 33. The controller 33 vertically moves the brush 17 by a brush moving mechanism 31 and changes a pressing amount X to an aluminum plate 15 so that the amount of the brush 17 becomes constant. A classifier 24 classifies polishing material particles in a abrasive material slurry 20 according to particle size, and discharges the particles of small size from a discharge tube 28. A pressing force of the brush 17 to the plate 15 and the size of the particles are regulated predetermined, and grains of predetermined roughness is uniformly formed on the plate 15. Since only the reduced particles are discharged, consumption amount of the material is reduced as compared with a conventional method of replacing all the amounts of the slurry 20 in a polishing material supply tank 12. Since the discharge amount of the discarded material is reduced, its discarding cost is largely decreased. |
