The Formulation of a Mathematical Model for Plasticating Screw Extrusion

Abstract The theory of plasticating extrusion has reached the stage where scientific design methods can replace the empirical ones. It is possible today to build a mathematical model comprising the whole plasticating extruder. This model predicts the temperature and pressure profiles along the extruder, the solids content everywhere in the extruder, the total power requirements and even the temperature fluctuations of the extruder. These developments were made possible by the recent mathematical formulation of the melting mechanism in the extruders, by a more accurate formulation of the melt conveying theories and by the availability of high speed digital computers. The development of such a mathematical model is discussed in this paper. The model has been built by a stepwise process of improving existing theories and eliminating critical simplifying assumptions and undue complexities. This has been accomplished by comparing the computer simulated results with their experimental counterparts. The applicat...