Enhance Your Aluminium Extrusions Through Different Finishes

  • Using aluminium for your project is beneficial in several ways, as this metal is not only cost-effective and versatile, but also has a high strength-to-weight ratio and non-corrosive properties. Aluminium finishes can be beneficial for extrusion, as they can improve corrosion resistance and enhance the appearance of aluminium. Aluminium has the tendency to naturally protect itself from corrosion, due to the oxide film that covers it. While the oxide film is capable of protecting the aluminium from various applications, in some cases you might need extra protection. Choosing a certain finish can also enhance the look of the extrusion that matches your vision for the project.

    There are primarily six different types of aluminium finishes available for extruded aluminium that serve different purposes and can be used in various applications based on their differentiation.

    Mechanical finishes: 

    Like other metals, the finishing process of aluminium is also kind of similar. However, as aluminium has certain characteristics, like aluminium alloy, sometimes special equipment can be required for a higher quality finish. In mechanical finishes, it removes the metal by abrasion, such as through polishing, buffing, blasting, and grinding or sanding. These polishes help aluminium to improve the surface quality and often a texture can be applied by way of force, as aluminium is a much softer metal than steel.

    Pre-treatment: 

    In this process, the aluminium is cleaned or etched with alkaline or other acidic materials, after which a pre-treatment coating is applied. This added coating provides necessary resistance against corrosion by enhancing powder or paint adhesion.

    Bright dipping:

    Some aluminium finishes can provide a mirror-glazed finish by performing bright dipping. In this process, the aluminium is put into a special dip, which is a combination of phosphoric and nitric acids to give that mirror finish to the extruded aluminium. After this process, the aluminium can also be anodized, which helps in thickening the oxide layer that provides corrosion-resistance to the metal.

    Anodizing:

    Through this process, the aluminium gets additional protection, besides having the natural oxide film. This anodic oxide is durable and comes in multiple colours and can also be used with any kind of aluminium alloy.

    Liquid paint:

    Liquid coatings contain organic compounds and come in various colours and thickness. They are usually driven off during the baking or curing process, after which the volume solids form a film on the extrusion.

    Powder coating:

    In the powder coating process, certain substances like pigments and levelling agents are mixed and combined to get the desired coating. The whole method goes through a melt mixing, cooling, and grinding process and is applied to the aluminium through a spray gun for a pristine finish. This process is one of the most popular finishes and can provide a variety of colours and gloss levels depending on your choice.

    Aluminium extrusion can be required for a variety of applications and thus it is necessary to choose the right finish that fits your purpose.