There are three stages for aluminum extrusion processes: Casting, extruding and oxidization.

Casting

Compounding in the aluminum extrusion press
Calculate specific amount of various alloy and fix various raw materials properly according to the specific alloy grades of the required products.

Smelting the prepared raw material
Put the prepared raw material into the smelting furnace for smelting by following specific requirements of smelting process and eliminate slags and gas from the furnace by degassing and slag removal.

Casting
Conduct cool casting to the molten aluminum under certain casting condition through the deep wall system to achieve round casting billets diversified in specifications.

Extruding

• Designing and creating a die based on cross-section of the aluminum extrusion profiles;
• Using aluminum extrusion press to achieve extrusion forming of the heated round casting billets;
• Adopting forced air quenching and the subsequent artificial aging process to complete heat treatment strengthening, with the heat treatment system for heat treatable alloys with different alloy grades.

Oxidization

The extruded aluminum profiles feature poor corrosion resistance, in which surface anodizing is required to enhance corrosion resistance, abrasiveness and appearance of the aluminum profiles.

Surface pretreatment
Conducting surface cleaning to the aluminum profiles through chemical or physical approach to make the pure aluminum profile exposed, thus getting complete and compact artificial oxide film, besides, the polished finish of surface can also available by mechanical processing.

Anodizing
The aluminum profiles, after undergoing a surface pretreatment process, can achieve anodizing on its surface under proper process conditions and forming AL203 surface film featuring compact, multi-pore and highly absorptive.

Pore sealing
Seal the film pore of anodized porous oxide film to make the film pollution, corrosion and abrasiveness free. The oxide film is colorless and clear, using high absorption of pre-sealed oxide film to absorb and deposit some metal salt within in the film pore, which can give aluminum profiles multiple colors in appearance except fot its original color.