Alkaline cyanide-free zinc continues to gain in popularity because of its superior metaldistribution. Problems typically associated with the process, however, include blistering, anodepassivation and discolored chromate layers. These problems demand careful control of severalparameters, often interrelated variables. This paper discusses an integrated concept that controlsthe factors affecting bath performance and finishing quality through newly conceived criticalprocess elements: True inert anode design to prevent metallic contamination, improve currentdistribution and reduce consumption of organic additives; small-size zinc generators designedwith catalytically coated baskets for accelerated dissolution of zinc for uninterupted large-scaleproduction; and a fully automatic system for the control and delivery of zinc concentrate,alkalinity as well as additives, with the full parameters’ documentation. The total concept, usedusccessfully at various installations, provides applicators with constant quality, supported bydocumented data.
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