ELECTROLYTIC TREATMENT METHOD

摘要

A method of electrolytic treatment on the surface of metal web, such as may be employed to fabricate offset printing plates supports, in which the rate of consumption of graphite electrodes used with the process is remarkably reduced. A current having asymmetric positive and negative half cycles is applied between graphite electrodes disposed in a main cell. A portion of the current of the half cycle having the larger average value is applied to an auxiliary anode electrodes provided in an independent auxiliary cell separated from the graphite electrodes. The auxiliary electrode is made of an insoluble material. By making the current density for anode reaction on the surfaces of the graphite electrodes smaller than the current density for cathode reaction on the surfaces of the graphite electrodes, the consumption rate of the graphite electrodes is greatly reduced.