In this TechForFuture project ‘Polymer Mixing in a Single Screw Extruder’ a method to optimize mixing elements is developed based on numerical simulations (Computational Fluid Dynamics, CFD). A numerical procedure is developed to calculate the flow field in the extruder. By tracing particles in this field data is collected to determine distributive and dispersive mixing. Based on these data measu-ring values, the so called resident time distribution and Shannon entropy, have been used to quantity mixing. This way numerical values can be compa-red to experimental values such that the developed procedure could be validated with experiment on a single screw extruder on labscale with diffe rent mixing elements. In the end, this numeri-cal procedure can be used to analyze, optimize and judge different mixing elements with respect to their performance. The work has been carried out in close collaboration with Wavin.