Anodising is a versatile and durable finish, used in a variety of applications, from architectural facades to machine parts. Anodising is an electrochemical process which forms an aluminium oxide coating on the surface of aluminium parts. To find out more about the anodising process, click here.
Often, project specifications ask for particular colours, either to brand or to colour code parts or equipment.
There are two main ways to colour anodising:
Because aluminium oxide is a porous material, it is possible for dye to be embedded in the pores before they are sealed. Once the parts are anodised, they are dipped in the dye solution, allowing the dye to fill the pores. The anodising is then sealed and its colour is maintained. Some dyes create a more consistent finish than others – black dye produces especially good results, and consistent colour each time.
Electrocolouring involves immersing the anodised aluminium in an electrolytic tin solution, which forms an organic ‘salt’ on the surface of the anodising. This salt is deposited at the bottom of the pores, and can then be sealed into the anodised finish. Different colours – and shades of the same colour – can be achieved by adjusting both the time the part is immersed in the tank, and the voltage applied.
Both standard and hard anodising can be dyed or electrocoloured.
It is worth noting that anodising can produce different colours or shades on its own. Most standard anodised finishes come out a silvery grey colour – this can vary depending on the micron thickness of the finish and the alloy used. On the other hand, hard anodising produces a charcoal grey colour, which also varies depending on alloy, and can appear darker depending on the micron thickness of the finish. Uncoloured anodised finishes are known as ‘natural’ or ‘clear’ anodising.
DECO offers an exceptional range of anodised finishes: DecoUltra. From its standard anodised finish DecoUltra AD, to its unique hard anodised finish DecoUltra ZD, DecoUltra offers finishes for all project needs. DECO offers a range of colours for all its DecoUltra finishes, including clear, black, gold and several different shades of bronze.
For more information on DECO’s anodising services and the colours we offer, contact us.