The extrusion process

There are several different extrusion methods. Direct and indirect extrusion are semi-continuous extrusion processes that take a variety of factors into consideration, including ingot weight, extrusion weight, extrusion profile length and cycle authorisation times.


ProfilGruppen uses Direct Extrusion.

There are also continuous extrusion processes, which are only used for small extrusions and simple pipes. However, the one thing all extrusion processes have in common is that the shaping process occurs during the brief moment the material passes the shaping pin in the tool. This is central to all extrusion pressing.

In order to secure a process with a sustainably high level of accuracy, tools must be precisely adjusted and utilised. In addition, process parameters must be carefully checked in order to ensure a high level of quality in production.

The extrusion process affords considerable freedom to the design of various extrusion cross-sections. At the same time, both the process and tool production are subject to a number of limitations.

The process of extrusion
Aluminium extrusions are manufactured by so-called power presses. An aluminium alloy billet is cut into suitable lengths, heated to 500 °C and then forced under very high
pressure through a die. The billet is forced through the die whose mandrel contours impart the shape in the extrusion drawing onto it. Depending on the alloy, extrusions are cooled with air and/or water after pressing. The extrusions are then straightened in hydraulic stretching equipment and cut into suitable lengths. Finally extrusion strength is increased by thermal aging, where the material’s natural hardening process is accelerated for five to eight hours at approximately 180 °C.