Overall, the model in this study uses the same AM and BC particle sizes and densities as well as the same force field coefficients (restitution, friction and rolling friction) as in our previous DEM model . However, there are still several differences in the geometry and particles properties between these two studies. First, the model in this work uses the same shape of a twin-screw as in the experiment, which significantly improves the similarity of the shear rate distribution in the extruder between the model and the experiment. In addition, we add a material injection barrel and a recirculation circuit to ensure that the particles would not be overflowed and lost during the simulation. This recirculation circuit is something that exists in the real extruder. Second, we set the different values for the material properties of BC particle and consider the material of PCL, which is not included in our previous model .