Aluminium Production Process at Alumex

Aluminium is a flexible metal that can be converted into different shapes using various production methods.

The production of aluminium extrusions starts with a billet, which is cut either from long imported Aluminium logs or logs produced in-house according to pre-defined specifications using pure Aluminium ingots, primary or secondary scraps. In the extrusion process, a certain pressure is applied on a heated billet which comes through a heated container through the die to produce a long profile. The die forms a crucial part of the production process to provide the correct flow pattern and accurate dimensions. Extruded profile is then cooled using chilled water or air. It is then stretched to achieve the required straightness and cut into standard lengths. These profiles are then aged at elevated temperatures to improve their mechanical strengths. Once completed, the basic extrusion form of ‘Mill Finished’ is achieved.

Decorative/protective surface finishes such as anodized, powder coated and wood effect are value added forms of Mill Finish profiles. Color, coating thickness, lengths and type of finishes are decided according to customer requirements.

Decorative/Protective Finishing Processes

Mill finish products: This is the basic form of the extruded Aluminium profile, having a raw, smooth Aluminium texture with mechanical strength and surface hardness. These products are widely used for pipes and hardware items.

Powder coating Process: A polyester powder mixed with color pigments are ionized through a pressure gun and sprayed onto the chemically pre-treated mill finish profiles, which are earthed and hung on a conveyor. The profiles which pass through the polyester powder ‘cloud’ are then subjected to deposits of powder onto the profile in a controlled manner to give a uniform layer. This profile with the dry powder on its surface is then passed through an oven for curing. The cured colored powder provides a lush durable texture to the surface. Various types of powder and pigments provide a large range of colors, shades and gloss texture to choose from.

Natural anodized Process: An accelerated and controlled protective layer is etched onto the mill finish surface using an electrolysis process. This process creates a uniform satin texture. The clear sealing process adds additional durability to prevent scratch marks. It is extremely durable for exterior applications including sea-side environments, particularly with a ‘high-micron’ coating.

Bronze anodized Process: Has the natural anodized finish with all the durability and surface characteristics. Various bronze shades are available depending on customer requirements.

Chemical polished Process: Profiles are submerged in a special chemical tank and a controlled ‘electrolysis’ process is performed to provide a fine smooth surface, which provides a mirror finish.

Wood Finish Process: This is a powder coated profile with a base colour to match the wood finish texture. The profile is wrapped in a textured film and passed through an oven to print wood finish surface texture. This process is called sublimation. Currently, Alumex offers three types of wood finish products, which resemble the Oak, Teak and Mahogany wood surfaces.