| 摘要 |
There is provided an apparatus and a process for using same for etching a metallic object (22), suitably a plate to prepare a metallic printing plate. The object is partially covered by a resist surface (14) wherein the exposed portions (16) of said metal, will be exposed to the action of an electrolytic etchant force. The apparatus comprises a bath (10) for an aqueous electrolyte (12), an electrode (23), suitably but not critically metallic, immersible in said electrolyte, which will serve as the cathode, a source of direct current voltage (32), which may further be associated with adjustment means (38) for controlling the applied voltage. The voltage should be adjustable to operate accurately within a rather narrow voltage range, such than the minimum voltage shall be at least that of the ionization potential of the metal of the metal object in the electrolyte chosen and the maximum shall not substantially exceed the sum of the decomposition voltage of the aqueous electrolyte and the over-voltage of the cathode selected.
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