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Powder Flow

In industrial processes such as blending, handling, storage, feeding, compaction and fluidisation the reliable flow of powder is important as it affects the quality of the final product or production rate. Poor flow leads to wastage, machinery maintenance problems and downtime, with associated costs.

Within our research group we have a number of devices for evaluation of powder flowability:

  • Schulze Ring Shear Tester
  • Instron 5566 Test Bench – used for uniaxial compression tests
  • Geldart’s angle of repose tester
  • Ball Indentation Method
  • FT4 Powder Rheometer of Freeman Technology
  • Tap density
  • GranuDrum of GranuTool

The Ball Indentation Method is a new technique for measuring flowability of cohesive powders and caking of hygroscopic powders by indenting the surface of a powder bed. This technique requires very small quantities of powder and can be applied on loosely compacted beds, making the technique beneficial to industries with problems of accessibility or availability of the testing powder, e.g. pharmaceutical industries with limited amount of powder in the early development stage or in the nuclear industry, where the amount of powder available for testing is limited due to ionising radiation risks.

Recently we have also developed an accelerated test method for powder caking, the Environmental Caking Rig (ECR) that enables rapid conditioning of a powder to desired environmental conditions and measurement of how powder flowability is transformed, which provides insight into how a bulk powder will behave in a supply chain during storage. We have recently reviewed the state of the art for dynamic powder testing: https://www.kona.or.jp/jp/journal/pdf/2020/kona.2020018.pdf