Assessing the mixing performance of extruders: indices and scale-up

This work proposes the use of global quantitative dispersive and distributive mixing indices to characterize the performance of a given screw. Calculation of these quantities uses a model of morphology evolution as a function of material and flow characteristics, which was coupled to a description of the flow developing along the screw from hopper to die. Scale-up on the basis of these indices is briefly discussed. Some results are presented in order to illustrate the usefulness of the methodology