Physical properties such as particle size, size distribution, shape, surface area, and density all play a role in how powders flow. Anyone who handles powders understands that flow properties can easily change when a material is moved from one environment to another. Environmental conditions during processing, handling, or transport, including temperature, humidity, electrostatic charge, and time can critically affect flow. For these reasons, multiple testing conditions should optimally be used to analyse the way a powder will flow in a given processing environment.
The test describes the flowability (cohesiveness) of the substance in accordance with the procedure described in Ph.Eur. Additionally, the angle of repose can be measured.
For Material Experts:
Instrument and measuring principle
The flow rate (g per sec.) for a predetermined amount of substance is measured in a standardised funnel described in Ph. Eur. The aperture diameter can be varied.
Sample amount: 80 g of the substance
Liu LX, Marziano I, Bentham AC, Litster JD, White ET, Howes T (2008) Effect of particle properties on the flowability of ibuprofen powders. International journal of pharmaceutics 362(1-2):109-117.