What is Direct and Indirect Extrusion?

By June 15 , 2016


Direct Extrusion

  • 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

  • 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.

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