Plasticising
During plasticising, mechanical energy is converted into heat through friction, which melts and homogenises plastics in the plasticising unit of an injection moulding machine, an extruder or another screw machine. This process must run evenly and gently in order to avoid hidden defects in the moulded part.
Uneven plasticising leads to different temperatures in the material, which causes material layering. These layers create interfaces with inhomogeneities that lead to high stresses and cracking inside the material.