Manufacturing method and manufacturing apparatus of support for planographic printing plate

A manufacturing method of a support for a planographic printing plate, comprising a surface roughening step for roughening at least one surface of an aluminum web continuously traveling,

• the surface roughening step comprising:
• an alkaline etching step of etching the aluminum web by bringing the aluminum web into contact with an alkaline solution;
• and
• an electrolytic surface roughening step of electrochemically roughening the etched aluminum web in an acid electrolytic solution,
• the method further comprising an anode oxidation treatment step for performing an anode oxidation treatment on the aluminum web of which surface is roughened in the electrolytic surface roughening step in an acid solution, so as to form an anode oxidation film on the aluminum web,
• the electrolytic surface roughening step including:
• a circulation step for cyclically using the acid electrolytic solution between an electrolyzer and an electrolytic solution reservoir during adjusting composition concentration of the acid electrolytic solution;
• and
• a filtering step of filtering the acid electrolytic solution cyclically used so as to remove solid matter in the acid electrolytic solution,
• and/or
• the anode oxidation treatment step including:
• a circulation step for cyclically using the acid solution between a feeding tank and an acid solution reservoir, and between an electrolytic treatment tank and the acid solution reservoir during adjusting composition concentration of the acid solution;
• and
• a filtering step of filtering the acid solution cyclically used, so as to remove solid matter in the acid solution, wherein
• in the filtering step, abrasive is added as a filter aid in the alkaline solution to be filtered,
• wherein the manufacturing method further comprises a step of performing mechanical surface roughening on the surface of the aluminum web with the abrasive before the alkaline etching step, and
• used abrasive generated in the mechanical surface roughening step are used in the filtering step.