Rotobarrel galvanising
Barrel galvanising is used for small metal parts, screws, bolts etc. The parts are placed inside barrels and processed in bulk. Acid zinc plating is preferred because it is better suited to different base materials (AVP, cast iron, zamak), and because of its brilliance.
Alkaline zinc
This galvanising process provides our excellent thickness distribution even on objects with very complex geometries.We recommend this treatment as the best for reaching maximum corrosion resistance and thickness uniformity.
Acid zinc
A galvanising process particularly suitable for all items for which appearance prevails over deposit uniformity. Recommended for ‘difficult’ materials such as Pb steels (AVP, PR80..) and cast irons.
Passivations
Passivation is a post-galvanisation treatment, consisting of the formation of a thin layer or film that aims to enhance protection against zinc oxidation (white rust). It has different colours according to type.
Blue passivation
Passivation that gives zinc a pleasant light blue colour and good corrosion protection (> 24h salt spray). The chromatisation layer is free of chromium 6 and cobalt.
Yellow or tropical passivation
This passivation gives the treated objects a distinctive and pleasant yellow colour with red reflections. Very popular in furnishing, it gives high corrosive protection to zinc (> 200h salt spray). The chromatisation layer contains cobalt and complies with RoHs 2011/65 EU directives.
High-resistance or technical passivation
The high-strength passivation refers to the capacity to increase the corrosion ‘resistance’ of zinc, by virtue of which protection reaches 240h in neutral salt spray. The appearance is iridescent with pink and green hues, and a yellowish hue if the zinc is electro deposited from alkaline solution, and neutral if from acid zinc. It contains cobalt and complies with RoHs 2011/65 EU directives.
Black passivation
Passivation used for decorative purposes, to prevent light reflection and to improve heat absorption. It has a considerable thickness (2μm), moderate corrosion resistance (24<Bk<48), and is therefore often sealed or painted. For alkaline zinc we use triple-function passivation, which complies with RoHs guidelines, while for acid zinc we currently use 6-function passivation with silver salts.
