Modeling melt conveying and power consumption of co-rotating twin-screw extruder kneading blocks: Part B. Prediction models

Intermeshing co-rotating twin-screw extruders are very versatile because their screw configurations can be tailored both to the application and to the properties of the materials used. Finding the best screw configuration is one of the main purposes of twin-screw extrusion modeling, and requires models that accurately predict conveying and power consumption. The better the process can be predicted, the better the requirements of the final product can be met. We present novel prediction models of the conveying and power-consumption behaviors of intermeshing co-rotating twin-screw extruder kneading blocks for Newtonian fluids. These are based on numerical simulations and therefore consider the complex three dimensional (3D) geometry of this element type without the need for common simplifications. Our models are thus capable of including all leakage flows and gap influences, which are usually ignored, for example, by the flat-plate model. Since our models are derived by symbolic regression based on genetic programming, they consist of algebraic functions and are low-threshold. They can be used to calculate various process parameters for individual kneading blocks or entire screw configurations, as illustrated by a use case.