Metal Colours Limited

Metal Colours Limited

Zinc Plating

Description:
Zinc Plating: Three automatic rack plants with a maximum process window of 3.6m x 1.5m x 0.7m. Two large automatic barrel process plants with 1.2m cylinders. The process solutions are alkaline non-cyanide based. Clear, Colour and Hexavalent Chrome Free passivation and topcoats are available. All plants have fully automated transporters with a high degree of process control, which includes automatic dosing of process chemicals and additives as well as process solution temperature and direct current control.

Benefits: Zinc is the process of choice for a cost effect method of achieving enhanced corrosion protection. It is also an ideal sub-surface for final finishing. [top]

Corrosion Protection: Corrosion protection is directly proportional to the electroplate thickness (3-30µm according to our client's specification). The principal protection is due to the zincs encasement of the item, which prevents contact with the environment. An important feature of zinc is it’s sacrificial property, which means that where the ferrous base of the item is exposed to humidity for example, the associated chemical reactions of corrosion will affect the zinc in preference to the steel. Zinc also provides outstanding metal distribution and uniform covering power. The coating is capable of accepting the environmentally friendly clear blue trivalent chromium passivate as well as yellow and olive drab finishes.

Wear Protection: Zinc plating bestows an increased surface hardness on the item with the finished hardness (100g HV) ranging between 80-150HV. Zinc is beneficial where items must retain their original appearance for many years. [top]
Corrosion Protection
White-h Red-h
Clear Passivate 20 100
Yellow Passivate 70 150-200
Hexavalent chrome Free Thick Film 130 300
Olive Drab Passivate 150-200 250-360
Black Passivate 30-50 120-50
Above data relates to corrosion testing in accordance with ASTM B117 procedures, 5% neutral salt spray, and deposit thickness 8µm. Silicate post dips and lacquers can add 100-250h to the above values. Protection of steel substrates (red rust corrosion) is proportional to the deposit thickness.

Value Added Services: Zinc plating can be used as a final finish or as a base for post-treatments. Additional treatments can be applied to complement the primary finish such as clear or coloured lacquering, oil seals, wax silicate finishes, leach and seal systems or wax emulsions dosed with corrosion inhibitors. Post treatment applications can be applied for functional or aesthetic purposes. [top]