Profile design of extruded aluminium profiles

Special profile from Alumeco

Extruded special profile from Alumeco

On this page you will find information on how to manufacture extruded aluminium profiles and what ground rules to take into account in connection with their design.

Manufacturing of extruded aluminium profiles

Extrusion is a process whereby profiles are moulded. The extrusion process resembles squeezing toothpaste out of a tube. The toothpaste is a heated, cylindrical aluminium block also called a billet while the toothpaste tube is the so-called tool. As you can see in the illustration, the billet (pre-heated in an induction furnace to 450-500 degrees Celsius) is pushed through the tool/die, at which the profile is brought to the desired shape.

When the profile leaves the tool, it is cooled with water or air, after which the profiles are drawn while they are still "soft". This removes any tension build-up in the aluminium while the desired and correct profile dimensions are achieved. The profiles are then cut and afterwards given their final strength by being subjected either to heat and/or to cold hardening.

Many options and golden ground rules

There are many opportunities when it comes to profile design, but there are certain ground rules which should be taken into account to optimise the profile's suitability for production. This way you will typically create the most suitable design solutions for your profile design.

The table below displays selected examples of extruded profiles with preferred design shapes. The table is simplified, which is why you should always contact us as early as possible during the concept phase.

 

To prefer To avoid Comments
    Arrange hollows symmetrically, if possible.
    Open screw channels show a better geometrical accuracy in relation to each other and give a longer life to the die.
    Peaks should be rounded (avoid filling problems; higher extrusion speed).
    Narrow slits only if unavoidable, otherwise add spacers whereby the tolerances of the opening distance are considerably improved.
    Contours which are connected with an unfavourable flow of material reduce extrusion speed and induce tolerance problems (for the cross section as well as for straightness and torsion).
    The tolerances for polygonal formed open cross sections can be improved considerably by adding stiffeners or by designing a hollow section.
    Small geometries of a thick section are difficult to fill out with metal and sometimes cannot be extrduded.
    Small appendices in connection with thick parts of a section are hard to fill with metal and sometimes cannot be extruded.
Avoid too thin or too wide walls in hollow sections (problems with tolerances, increased
waste since defect not repairable). Arrange supporting spacers.
  • Billet on the way to be extruded
  • Billet on the way to be extruded
  • View of a typical aluminium press

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Extrusion
Assembly and packaging
Cutting