Electrograining of aluminium in HCl: effect of the alloy for high‐speed processing lines

Abstract

AbstractElectrograining of aluminium in hydrochloric acid is one of the most commonly used processes for manufacturing printing lithographic plates. Two of the main features to be taken into account are the final morphology of the electrograined surface and the susceptibility of the alloy to be processed or, more specifically, the speed of the processing line. Both issues determine the efficiency of the production in terms of quality and time. In this work, a widely used commercial aluminium alloy (1050) is compared with a new experimental one (1050 modified with Zn) and with a higher strength alloy (namely 1020). In order to analyse their response to a.c. graining in HCl for high‐speed lines, some techniques such as image analysis or interferometry have been used. In general, the alloys doped with Zn and Mg present a better response to litho processing in terms of graining activity and reduction of streakiness when treatment of lower time periods is applied due to their influence as pitting initiators. Copyright © 2010 John Wiley & Sons, Ltd.