(448ac) Measurement of Permeability of Powder with Reference to Flow Behaviour

Recent research has highlighted the importance of particle-air interactions in powder processing. For example, air pressure increase during powder discharge into closed cavities opposes powder flow and affects powder dosing processes such as die fill on rotary powder presses. The permeability of the powders is a property which influences flow performance under such conditions.

In this research a system is designed to measure the permeability of a range of powders used as excipients in pharmaceutical formulations. Starting from bulk density, the system is used to measure the permeability of the powders at different solid fractions by applying a small degree of compression.

The results are discussed in relation to flow rate measurements during bin discharge in an enclosure where the air pressure (or vacuum) is controlled.