K.Walter – A complete “4-in-1” solution for chrome plating of gravure cylinders
GERMANY • “4-in-1” is the key advantage of the new HelioChrome Rapid EC for the chromium plating of gravure cylinders. The essential additives – which previously had to be added for various effects – are now included in the product.
For optimum composition of the chromium layer, various additives were previously added to the bath and dosing errors could not be ruled out. Now that additional additives are unnecessary, as HelioChrome Rapid EC is said to offers consistently stable results. This also eliminates the need for the formerly used lead anodes.
HelioChrome Rapid EC is based on chromic acid and includes the additives HelioChrome Rapid Catalyst, HelioChrome Wetting Agent FF and HelioChrome REOX3, which are responsible for various galvanic effects. The Rapid Catalyst supports electrolysis to give the chromium layer maximum stability. Specifically, hardness, roughness and microcracks are steered into the respective ranges. Thus, the range for the desired corrosion-resistant microcracks is most favorable between 300 and 600 cracks per centimeter.
Wetting Agent FF is a PFOS-free (PFOS = perfluorooctane sulfonate, an anionic surfactant of perfluorooctanesulfonic acid) wetting agent that can reduce the surface tension of the electrolyte from over 70 mN/m to less than 30 mN/m. “FF” stands for “foam-free”. Under normal conditions, the formation of gas bubbles and thus of surface foam and spray mist is negligibly minimized. This is advantageous because it considerably reduces the chromium content in the exhaust air and lessens the risk of hydrogen depletion. And since the electrolyte spreads much more, the system is easier to clean; there is hardly any carryover. At the same time, greater contamination of the chromium plating bath is avoided, which saves cleaning effort and protects the system hardware.
REOX3 controls the trivalent chromium in the electrolyte and is the decisive component for electrolysis without lead anodes. This is extremely welcome from the point of view of occupational health and safety because operators no longer have contact with the previously used lead anodes, i.e. they no longer need to clean them.