Flow properties of powders using four testers - measurement, comparison and assessment

The flow properties, i.e. cohesion and slope of the yield locus, of wheat flour and sugar were measured using four testers, namely, the triaxial cell, the direct shear cell, the Jenike shear cell and the rotational split-level (RSL) shear cell over a range of loading conditions. A statistical comparison was done at the 0.05 level of significance (P<0.05) to evaluate the performance of the four testers with respect to the yield loci. For wheat flour, the flow properties determined from the Jenike shear cell, the direct shear cell, the triaxial cell and the RSL shear cell experimental data were not significantly different. For sugar, however, the test results from the RSL shear cell were significantly different from the other three testers. Therefore, the four testers seemed appropriate for determining the flow properties of wheat flour and similar powders, whereas, the Jenike shear cell, the triaxial cell and the direct shear cell seemed appropriate for measuring flow properties of sugar and similar powders.