Hosokawa powder tester

Hosokawa micron powder tester A practical way in which reproducibility of aeration or the attainment of conditions of low stress packing can be achieved is to use a Hosokawa Powder Tester (Hosokawa Micron Ltd) (Figure 1.3). This powder tester deposits an aerated powder into a test cup, which thus gives an aerated volume. From the mass of this aerated bulk powder the density, with a very open structure, can be calculated. 

Studies have also been conducted comparing the Jenike direct shear test method to other test methods used to measure a powder s flowability (3), including the Hosokawa Micron Powder Characteristics Tester (Hosokawa Micron, Osaka, Japan), Peschl shear tester, and Johanson Hang-up Indicizer (Johanson Innovations, San Luis Obispo, California, U.S.A.). This is not an exhaustive list of all the powder testers available. In general each tester has its own test method, which measures some property of the powder that changes as the flowability changes. As stated previously, however, the term flowability must be taken in context. 

Another, this time indirect, method of assessing flowability was proposed by Carr36. This was based on measuring four properties of the powder (angles of repose and spatula, compressibility and uniformity coefficient, all as defined by Carr36) and, by awarding points (out of 25) for each, the sum total was then a measure of flowability and called Carr s Index . A commercial piece of equipment is available (Hosokawa Powder Characteristics Tester) for measuring the properties necessary for Carr s Index. 

Fig. 11.7 Photograph of the micron powder tester (courtesy Hosokawa Micron Powder Systems, Summit, NJ, USA).

H.G. Brittain, unpublished flowability results obtained using a model PT-D Powder Characteristics Tester manufactured by the Hosokawa Micron Company. The Carr flowability index was determined from the individual indices derived from measurements of the angle of repose, compressibility, angle of spatula, and cohesion. 

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