Powder Flow Properties

In addition to providing analysis of particle size, shape, surface area, and density, Particle Testing Authority can perform measurements of powder flow properties using the FT4 Powder Rheometer® and provide application support from the experts at Freeman Technology (recently acquired by Micromeritics) based on real-world experience.

Any organization that incorporates the flow of bulk powders in any part of their process has a lot to gain by measuring and understanding the flow properties of their powders whether it is to optimize a formulation in a development environment, predict in-process performance, understand batch differences, or to ensure the quality of raw materials or intermediates.

Different particle sizes, shapes, surface area, etc. Every particle is unique

Smooth, spherical, monodispersed particles

Spherical, but highly porous structure and rough surface

Volcanic ash sample demonstrates the complexity of individual particles


Providing a Comprehensive Understanding of Powder Behavior

Traditionally a small number of limited measurement techniques (particle size distribution and angle of repose, for example) have been commonly used to describe the flow behavior of powder.  However, other particle properties such as shape, surface texture, density, friability, and hygroscopicity will have a significant influence on the flow energy, cohesive strength, shear strength, and wall friction of the bulk powder. Here at PTA, we can measure these properties and more with highly reproducible results using these well-defined methodologies:

  • Stability and Variable Flow Rate
  • Aeration
  • Permeability
  • Compressibility
  • Shear Strength (ASTM D7891)
  • Wall Friction (ASTM D7891)

The above methodologies allow powder samples to be comprehensively characterized for the extremes of packing and environmental conditions that occur in everyday processing.


Understanding Powder Behavior:


  • Filling
  •  Tablet compression
  •  Hopper Flow and Design
  •  Wet granulation end point and scale up
  •  Flow additive selection and optimization
  •  Humidity effects
  •  Electrostatic charge
  •  Mixing / Blending
  • Feeding
  • Segregation
  • Attrition
  • Dry powder inhalers
  • Caking
  • Milling
  • Conveying
  • Wall friction and adhesion
  • Compact hardness and payoff

Mechanism that contribute to powder flow