Fully automated wall friction measurement
A new module for the Freeman Technology FT4 Powder Rheometer allows fast now, fully automated measurement of wall friction using standard or custom materials in contact with powders under test. That what the company based in Worcestershire, UK, recently announced. This new module further extends the capabilities of the FT4, a system that is rapidly becoming a universal powder tester. The FT4’s new wall friction module allows experimental measurement of frictional resistance with a total test time of around 10 minutes. A 48 mm diameter disc of the appropriate material and finish is used to compress a powder sample through a step sequence of predetermined normal stresses. At the same time, the disc is rotated and the shear stress is determined from measurements of the frictional torque at each stress level. The wall coefficient of friction is then calculated from the slope of the shear stress versus normal stress data. The wall friction module comes with a set of four grade 304-stainless steel discs with various surface finishes. The simplicity of the disc design means that additional discs featuring specific materials and surface conditions can be produced easily.