Tools to Simulate Distributive Mixing in Twin-Screw Extruders

The application of the mapping method in finite element modeling is extended to quantitatively compare mixing in different twin‐screw extruder layouts. The mapping method provides volumetric quantities, which are crucial for the analysis and optimization of mixing based on the tracking of particles in the velocity field. A new approach to the mapping method is developed to analyze mixing in complex, dynamic open geometries. Several screw configurations and different types of conveying screws are compared, changing the pitch and gap widths. The volume‐weighted intensity of segregation is used as a mixing measure. With a novel three‐dimensional extended finite element method, truly accurate velocity fields in twin‐screw extruders operating under realistic conditions are computed. These serve as input for the mapping method, which does provide volumetric quantities and allows a quantitative analysis of mixing in different screw layouts. The figure shows the beauty of mixing.