Attribute Characteristics:

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.