Colour anodising aluminium

Chemical process …

Colour anodising of the initially colourlessly anodised aluminium with organic or inorganic colour solutions. The colour range is unlimited but only some colours are non-fading.

Colour anodising of oxide coatings …

Colour anodising of the previously colourless anodised oxide coating by electrolysis, applying alternating current in metallic salines (electrolytic process = 2-step process). The range of colours is as follows: from nickel silver via brown to black (e.g., Colinal^©).

General…

Demands of production require profiles (moulding) and metal sheets (rolling) with different surface structures. This also affects any later colour anodising process so that even colouring is close to impossible and blotches cannot be avoided.

Sealing

All oxide layers are porous. Closing the pores requires sealing in boiling water (with or without additives). This is a very complicated swelling process. Only by sealing will the oxide coating receive its excellent qualities. To extend the design options, methods were developed to apply coloured oxide coatings on aluminium. Colour effects of anodised aluminium can in principle be achieved in several ways.