Home > Learn > Wiki > What are the compressibility and Hausner ratio?

# What are the compressibility and Hausner ratio?

2023-02-10WIKI

The compressibility and the Hausner ratio can be calculated using the bulk density and the tapped density, which are utilized to indicate the flowability of powder material.

The calculation of the compressibility:

The calculation of the Hausner ratio:

where ρT is the tapped density, and ρB is the bulk density.

The flowability of a powder can be characterized based on the compressibility or the Hausner ratio. A lower compressibility or a lower Hausner ratio of a material indicates better flow properties. A compressibility of <10 or a Hausner ratio of <1.11 is considered an “excellent” flow, whereas a compressibility of >38 or a Hausner ratio of >1.60 is considered a “very poor” flow.

 Flowability Compressibility Hausner Ratio Excellent <10 1.00-1.11 Good 11-15 1.12-1.18 Fair 16-20 1.19-1.25 Passable 21-25 1.26-1.34 Poor 26-31 1.35-1.45 Very Poor 32-37 1.46-1.59 Very Very Poor >38 >1.60

The flowability of a powder material can be evaluated by integrating the compressibility, the Hausner ratio, and the angle of repose. It is also possible to predict the flowability of the material through individual parameters.

 Struggling to grasp particle analysis concepts? Our new Beginner's Guide to Particle Analysis is here to help you grasp these concepts in the most accessible manner possible. Download it as a PDF to read on the train, on the plane, or wherever else there’s no internet.