Process for electrochemically roughening aluminum for printing plate supports

摘要

Disclosed is a process for electrochemically roughening aluminum or alloys thereof, in an aqueous electrolyte, under the action of an alternating current which is generated by superimposing at least two types of alternating current of different frequencies. The materials roughened in this manner are used as supports for radiation-sensitive reproduction coatings in the field of manufacturing offset-printing plates. Also disclosed are roughened aluminum supports and printing plates produced by the above process.