Modelling of Mixing in Single Screw Extruders


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Polymer extrusion is one of the most important polymer processing techniques. Modelling of the phenomena developing inside single screw extruders enabled the development of commercial software which can be used to study the performance of existing systems and to define the equipment characteristics for new applications. Although mixing is one of the most important performance measures of extrusion, it is usually disregarded in the available programs. Consequently, in this work mathematical models for quantifying mixing in single screw extruders are developed and subsequently inserted in a global computer modelling program of single screw extrusion. The mixing model quantifies distributive and dispersive mixing and coalescence mechanisms in a liquid-liquid system. This is accomplished by calculating the variation of the thickness of drops considered to be suspended in the polymeric matrix, taking into account the rate and drop break-up time and the coalescence probability. The influence of several parameters, such as viscosities, initial drop dimension, screw speed and barrel temperature, are examined



Materials Science Forum (Volumes 514-516)

Edited by:

Paula Maria Vilarinho




N. Domingues et al., "Modelling of Mixing in Single Screw Extruders", Materials Science Forum, Vols. 514-516, pp. 1409-1413, 2006

Online since:

May 2006




[1] H.E.H. Meijer, J.M.H. Janssen, Mixing of Immiscible Liquids, In I. Manas-Zloczower, Z. Tadmor, Mixing and Compounding of Polymers, pp.85-147, Hanser Publishers, Germany (1994).

[2] J. L. White, Polymer Mixing - Technology and Engineering, Hanser Publishers, Germany (2001).

[3] T. A. Osswald, Polymer Processing Fundamentals, Hanser Publishers, Munich (1998).

[4] N. Domingues, Modelação Matemática de Mistura em Extrusão de Polímeros, Master Thesis, University of Minho, Guimarães (2004).

[5] J.M. Ottino, The Kinematics of Mixing: Stretching, Chaos and Transport, Cambridge Univ. Press, UK (1989).

[6] A. Gaspar-Cunha, Modelling and Optimization of Single Screw Extrusion, PhD Thesis, University of Minho, Guimarães (1999).

[7] I. Manas-Zloczower, Analysis of Mixing Polymer Processing Equipment, Rheo. Bull. 66, n. º 1, pp.5-8 (1997).

[8] Y. Renardy, V. Cristini, J. Li, Drop Fragment Distribution under Shear with Inertia, Int. J. Multiphase Flow, n. º 28, pp.1125-1147 (2002).


[9] H. P. Grace, Dispersion Phenomena in High Viscosity Immiscible Fluid System and Application of Static Mixers as Dispersion Devices in such Systems, Chem. Eng. Comm., 14, pp.27-52 (1982).

[10] Y. W. Stegeman, Time Dependent Behaviour of Droplets in Elongational Flows, PhD Thesis, Technische Univ. Eindhoven, Germany (2002).

[11] L. A. Utracki, Z. H. Shi, Development of Polymer Blend Morphology During Compounding in a TwinScrew Extruder, Polym. Eng. Sci. 32, n. º 24, pp.1824-1833, (1992).


[12] L. Delamare, B. Vergnes, Computation of Morphological Changes of a Polymer Blend along a Twin-Screw Extruder; Polym. Eng. Sci. 36, n. º 12, pp.1685-1693 (1996).


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