Plasticating single-screw extrusion involves the continuous conversion of loose solid
pellets into a pressurized homogeneous melt that is pumped through a shaping tool. Traditional
analyses of the solids conveying stage assume the movement of an elastic solid plug at a fixed
speed. However, not only the corresponding predictions fail considerably, but it is also well
known that, at least in the initial screw turns, the flow of loose individual pellets takes place.
This study follows previous efforts to predict the characteristics of such a flow using the discrete
element method. The model considers the development of normal and tangential forces resulting
from the inelastic collisions between the pellets and between them and the neighbouring metallic
surfaces. The algorithm proposed here is shown to be capable of capturing detailed features of the
granular flow. The predictions of velocities in the cross- and down-channel directions and of the
coordination number are in good agreement with equivalent reported results. The effect of pellet
size on the flow features is also discussed
