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EFFECTS OF SHEAR‐THINNING BEHAVIOR ON MIXER VISCOMETRY TECHNIQUES 3
Author(s) -
MACKEY K. L.,
MORGAN R. G.,
STEFFE J. F.
Publication year - 1987
Publication title -
journal of texture studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.593
H-Index - 54
eISSN - 1745-4603
pISSN - 0022-4901
DOI - 10.1111/j.1745-4603.1987.tb00900.x
Subject(s) - shear thinning , impeller , viscometer , materials science , shear rate , rotational speed , composite material , shear (geology) , rheology , mechanics , viscosity , mechanical engineering , physics , engineering
Brookfield RVTD and HBTD viscometers equipped with a flag impeller, having an impeller‐to‐cup diameter ratio of 0.55, and non‐Newtonian fluids 1.0% guar gum and 1.5, 2.0 and 2.5% carboxymethylcellulose were used to collect torque versus rotational speed 0.5–10.5 rad/s (0.5–100 rpm) data. Power Law consistency coefficient and shear thinning index were quantified using a Haake concentric cylinder viscometer. The proportionality constant which relates mixer shaft speed to effective shear rate (k 1 ) was very sensitive to the shear thinning index at low values of rotational velocity. Results indicate that it is not practical to use one constant value for k 1 when measuring properties of shear thinning fluids at low values of N or when using impeller‐to‐cup ratios significantly less than 1.0.