Surface treatment method and apparatus for graining aluminium base for printing plates

摘要

A surface treatment method and apparatus for graining a surface of an aluminum plate as a base of a printing plate, wherein graining brushes are pressed onto the aluminum plate and are turned to brush the aluminum plate to rub abrasive slurry on the aluminum plate surface.The amount of electric power required for driving the graining brush to turn at a constant speed to brush the aluminum plate is monitored and maintained constant by changing pressing amount of the graining brush onto the aluminum plate. A classifier continually takes in a part of the abrasive slurry from a slurry supply tank, classifies abrasive particles in the abrasive slurry according to their particle diameters, and feeds back those abrasive particles with larger diameters than a predetermined particle diameter to the slurry supply tank. Those abrasive particles with smaller diameters than the predetermined particle diameter are excluded from the abrasive slurry, so the particle diameters of the abrasive materials in the abrasive slurry are maintained in a predetermined range.