Aluminium Finishes
The natural finish and surface quality of aluminium in most cases is such that it can be used for many applications without any finishing required. There are cases in which different aluminium finishes are required for different reasons which include aesthetic improvement, different colour, better resistance to wear, improved reflectivity, better surface structure and improved electrical insulation.
At thyssenkrupp, we offer many different aluminium finishes each of which has different properties and is best suited for different applications.
Surfaces and finishes
This is the finish that the aluminium has as it comes out of the mill. In this finish, aluminium has a wide range of uses and applications. This is the original nature of aluminium and no mechanical or chemical finish is done on the surface.
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For clients that would prefer to have their aluminium surface finished, it is important to emphasise this to our team in order for the finish to be preserved during the extrusion process or during delivery. For more details on this type of finish, you can get in touch with our team.
Painting aluminium offers a variety of attractive colours and better ageing to the metal. The most common method of painting aluminium is powder coating, which requires pre-treatment prior to the application of the paint to ensure proper adhesion of the paint. Powder coating is preferred in paint finishing of aluminium profiles because:
- Powder coating is ideal for outdoor use
- The paint does not run or blister
- Powder coating withstands abrasion and knocks better than wet painting.
However, while powder coating is preferred, we also offer high-quality wet painting finishes for clients that prefer this alternative process. The paint finishing can be varied in the colours you choose and also the gloss level. We can apply the paint finishing at our mills or our customers can opt to have the finishing done by another independent finisher.
Anodising is a very common finish in aluminium profiles. There are a variety of benefits using this material, which includes:
- Maintaining the new appearance of the product
- Improving the ability of aluminium to withstand corrosion
- Aesthetic purposes
- Creating functioning specific surfaces
- Electrical insulation
- Creating touch friendly surfaces.
There are different layers of thickness of anodising applied to aluminium to achieve different benefits. The thicker the anodic layer, the better corrosion resistance and the better the finish.
This is a mechanically abrasive process that gives the aluminium surface a brushed or bright finish. Polishing is not a common process, but it presents different properties and benefits of aluminium. These include:
- Improved aesthetic appeal.
- Improve reflective properties of aluminium.
- Reduce product adhesion.
- Improve ease of cleaning the surface.
Cast plate finish is most commonly used when post machining work is done. With cast plate, the aluminium plate is cast in a block and all the six sides are then sawn dawn making them rough. The plate can then be machined and taken through other finishes to match the application that it will be used for.
Unlike cast plate, tooling plate is machined on the top and bottom surfaces to give a much tighter thickness tolerance and reduce further machining times.
Bright dipping gives the aluminium surface a shiny surface. It involves bathing the product in acid to smooth the surface and create a “mirror-like” finish.
While this process is required to create some products, it’s not recommended and is often discouraged.
This is a cheaper alternative to anodising. Alodining coats can be used to enhance the passivating oxide layer on the surface of the aluminium products. It also helps to enhance corrosion resistance.
The Alodining layer is not as strong or wear resistant as anodised aluminium, it has a high electrical conductivity that may be necessary for some applications.
This aluminium finish is seen in more artistic applications. It is the sublimation process for creating coloured patterns on aluminium. The patterns are transferred from a film wrapping onto the aluminium surface using heat.
Extruded aluminium is often preferred for this finish to create a wood pattern.