A model for solid agglomerate dispersion in single screw extruders is proposed. The model combines numerical simulations of flow patterns in the metering section of a single screw extruder with a Monte Carlo method of clusters rupture and erosion mediated by a local fragmentation number. Particle size distributions and Shannon entropy are used for mixing characterization. The model is quite general and can be adapted for different polymer-additive systems as well as for different processing equipment.

A mathematical model to predict the evolution of the morphology of immiscible liquid–liquid systems in single screw extruders has been developed. The model computes the dimensions of the dispersed phase in the polymeric matrix, taking into account the stretching, break‐up, and coalescence phenomena. The corresponding routine was inserted in a process modeling software, describing the flow in a single screw extruder from hopper do die. The drop dimensions were computed along the melting and melt conveying zones. This enabled the study of the morphological evolution of a two‐phase liquid system in a single screw extruder, taking into consideration the effects of the material properties, operating conditions, and screw geometry. The limited experimental data obtained was generally in line with the theoretical predictions. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers

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A model of agglomerate break-up, incorporating both rupture and erosion, is employed to predict the dynamics of filler size distribution in a plasticating single screw extruder. Filler spatial distribution along the extruder length was also ascertained and direct comparison of experimental and computational data proved to be satisfactory. The method was also used to investigate the effect of material properties, operating conditions and extruder geometry on the dynamics of agglomerate dispersion along a single screw extruder. Generally, dispersion levels were primarily governed by the magnitude of the hydrodynamic stresses developed in the extruder and the residence time in the melt.