Characteristic parameters and process maps for fully-filled twin-screw extruder elements

The shape and form of twin-screw extruder elements determine the physical conditions under which the material is processed. In this work, we investigated the pressure build-up, power consumption, dissipation and distributive mixing behavior of fully filled extruder elements via Smoothed Particle Hydrodynamics simulations, covering a wide range of conveying, kneading and mixing elements used in the ZSE12, ZSE18 and ZSE27 pharma extrusion equipment series. As a result, a comprehensive parameter catalogue of characteristic values was computed. These parameters allow studying the pressure build-up, power consumption and mixing behavior for all elements under various operating conditions. Additionally, we show novel process maps which support optimizing the length of a process zone. Properly used, the catalogue can assist a rational selection of screw elements during process design and transfer.