Anodising aluminium systems increase their resistance to corrosion and wear however due to the anodising process, it is often best practice to powder coat louvre mullions separately.
In a nutshell:
• Anodising involves an electrochemical reaction which creates a strong, durable oxide layer on aluminium.
• The build-up of the louvre system means that the electric current doesn’t always reach the mullions.
• This creates a knock-on effect as some clips don't have an oxide layer and are left undyed.
• Anodising the system in one can cause problems in achieving an even layer but anodising the parts separately is costly.
• PPC coating mullions is a more cost-effective solution that also helps suppress vibrations in the system.
Anodising is a popular method of colouring louvre systems due to its durability and sleek, metallic finish. This process is achieved through an electrochemical reaction, where an electric current is passed through aluminium in an electrolytic solution bath to create a very robust oxide layer which is later dyed a specified colour.
However, due to the build-up of a louvre system, it is best practice to powder-coat the supporting mullions and clips separately. One reason is that the clips that attach to the mullion have poor conductivity, meaning that when the electric current is passed through the mullion it doesn’t always reach the clips. Another reason would be that when the system is submerged in the bath, the electrolyte solution can get stuck between the metal parts due to capillary action and therefore doesn’t drain properly later on. These issues then have a knock-on effect on the dyeing stages because an oxide layer hasn’t been formed over the entire system leading to some areas being left uncoloured. Therefore, to achieve a consistent, high-quality finish, it is often best practice to coat the mullions separately.
However, anodising each louvre element would be very costly which is why many practices choose to powder-coat louvre mullions. Another benefit to powder-coating mullions is that because it covers the metal in a layer of polyester paint, it prevents the metal components from connecting and suppresses vibrations in windy conditions.