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A 2‐d numerical study of intermeshing self‐wiping screws in biopolymer extrusion
Author(s) -
LaiFook R. A.,
Li Y.,
Smith A. C.
Publication year - 1991
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760311513
Subject(s) - laminar flow , materials science , power law fluid , extrusion , mechanics , flow (mathematics) , plastics extrusion , finite element method , mixing (physics) , composite material , mechanical engineering , thermodynamics , engineering , physics , quantum mechanics
A knowledge of flow behavior is important in the study of laminar flow in twin‐screw extrusion processes to predict the velocity distribution and to understand the mixing process. The flow of a power law fluid in self‐wiping twin‐screw extruders is examined using a two‐dimensional finite element analysis of a mid‐channel section of intermeshing screws. Theory is compared with experiment using food biopolymer and plastic materials. Comparisons showing overprediction of throughputs, but similarities in behavior, suggest that this model could provide an upper limit for melt conveying. For most of the throughput range examined, pumping of intermeshing self‐wiping screws appears to be almost independent of the power law flow index of the melt extruded, but the value of the flow index determines the degree of influence intermeshing has on the overall pressure gradient generated in the extruder.