Shear cell powder testing aims to measure how much energy is required to initiate powder flow, for example, from a silo or hopper into a receptacle.
Using a Schulze Ring Shear Tester (RST XS), we slowly apply horizontal stress to the upper layer of powder when the bottom layer is restrained from moving – the test is complete when the powder bed "yields”. The force applied can be changed to mimic the scale of the process of interest and predict how the material flows from small hoppers to large IBCs.
The ring shear tester is very useful in power testing as it is able to test materials that are poor flowing, free-flowing or require large shear deformations. We use the results to predict how formulations will flow in process equipment e.g. tablet press hopper.