We use SolidWorks to design the extruder barrel and twin-screw geometry, followed by postprocessing and optimization of the STL files using Blender and MeshLab . In this way, we obtain a Computer-Aided Design (CAD) model of the extruder with an outlet diameter 50 times smaller than that of the experimental device, but with a good approximation of the relative proportions of twin-screw and barrel to the real extruder. We then process the STL file as an import file for use in the software LIGGGHTS .