Total Strain of Newtonian Fluids in a Vane Extruder

Abstract

The vane extruder, which makes a polymer suffer elongation stress much larger than shearing stress, is an innovational equipment in polymer processing. A physical model and a mathematical model are established to analyze the mixing characteristics in polymer processing, namely, the two important functions of residence time distribution and strain distribution function are obtained. It is shown that the direction of total strain gradient is consistent with the orientation of the material flow. The results show that the vane extruder has an advantage over traditional screw extruders due to it being based on elongational rheology.

A comprehensive review on flow field properties in polymer mixing processes: a focus on applications in energetic materials

“…It is equal to the product of the strain rate and the residence time. Huang [59] deduced analytical solutions for the velocity field and total strain based on a comprehensive analysis of a physical model of vane plasticizing and conveying units. The analytical solution enables the investigation of the influence of structural parameters on mixing effects.…”

“…Another parameter to characterize the percentage and distribution of tensile deformation was named the tensile deformation effect index, which was used to investigate the proportion of tensile deformation in mixing equipment and the effect of structural parameters [59]. Based on the scalar form of the second invariant of the deformation rate tensor, the tensile deformation as a percentage of the total deformation is defined as the tensile deformation effect index , h as in equation (7):  g is the rate of shear deformation in the x y-plane.…”