- Direct Extrusion is also known as Forward Extrusion. In this process the Ram of the machinery moves and forces the Billet (semi-finished metal form) through the die. It is the most common Extrusion process used.
- The disadvantage of direct extrusion is that the force required to release the billet out of the extruder is more than that required in Indirect Extrusion.
Read also : What is the Definition of Extrusion?
- Indirect Extrusion is a method in which the Ram is stationary and the dye moves forcing the Billet through the dye. So as to keep the die stationary a stem is used which should be longer than the container containing the Billet.
- The advantage of Indirect Extrusion is that there is reduced friction in the billet which helps in increasing the speed and efficiency of the manufactured product and extruder machine.
- No heat is formed due to friction in the process of indirect extrusion. Hence the extruded product does not crack and there is less wear and tear of the machine.
- The extruded material might comprise of some impurities hence the extruded product has to be finished or chemically treated before packaging and supply.