MANUFACTURE OF PRINTING PLATE

摘要

PROBLEM TO BE SOLVED: To inexpensively and stably manufacture a lithographic printing plate substrate for forming uniform pits and well keeping the quality level and the printing performance level of a chatter mark in a process of electrochemical surface roughening of an aluminum plate as one of the lithographic printing plate manufacturing processes. SOLUTION: An electrode 3 and an aluminum plate 4 in the state of being immersed in an electrolyte 2 are disposed in an electrolytic cell 1, and an ultrasonic oscillation element 5 is disposed below the electrode and the aluminum plate. The electrode 3 and the aluminum plate 4 are connected with an electrolytic treatment power source 6. In such an electrochemical surface roughening device, the power amount is adjusted to be in the range of 50-300 c/dm2 while emitting ultrasonic waves of 20-50 kHz frequency by the ultrasonic oscillating element 5 to surface-roughen the aluminum plate 4.