Modelling of flow and chemistry in twin screw extruders

Reactive extrusion involves the difficulties of mastering the twin screw extrusion process and controlling a chemical reaction under very specific conditions (high viscosity medium, high temperatures, short residence times). Therefore, it is often very difficult to understand all the aspects of the process and the complex interactions between the numerous variables, and then to properly optimise the industrial process. Numerical modelling can be a very efficient tool to overcome these difficulties. However, it is a real challenge, as the information needed is sometimes difficult to obtain with the required accuracy. After a general presentation of the principles of reactive extrusion modelling, different examples of applications are presented to illustrate the interest of the method.