Premium
Quantification of the slip phenomenon and the effect of shear thinning in the capillary flow of linear polyethylenes
Author(s) -
PérezGonzález José,
De Vargas Lourdes
Publication year - 2002
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.11026
Subject(s) - slip (aerodynamics) , materials science , extrusion , slip line field , shear thinning , capillary action , slip ratio , composite material , shear rate , critical resolved shear stress , shear stress , shear (geology) , mechanics , shear flow , rheology , thermodynamics , physics
The slip phenomenon in the capillary flow of linear polyethylenes and its relation to their shear‐thinning behavior was studied in this work. A simple macroscopic analysis that allows a description of the trend of the slip length and the contribution of slip to the average fluid velocity as functions of the shear stress is presented. From this analysis it is shown that an increase or decrease of the slip length for increasing shear stress is determined by the polymer architecture and the competition between slip and shear thinning. A similar behavior is observed for the ratio between the slip and whole average fluid velocities. The analysis is validated using experimental data obtained during the continuous extrusion of linear low‐density polyethylene melts under strong slip conditions in a brass die.