Abstract: A method is provided for characterizing powders and powder behavior in a rotating cylindrical container by image analysis techniques. Powder is placed in a generally cylindrical container with transparent ends. The container is then placed in front of an imaging device and illuminated with a light source so the device can capture images of the powder over time. The container is then rotated at various speeds and the camera captures images of the powder at fixed time intervals. Image analysis algorithms are then used to isolate the powder information in the images and this data is used to calculate several parameters of the powder including the potential energy of the powder, the curvature of the powder, and volume of the powder.

Abstract: An apparatus is provided for measuring the unconfined yield strength and time unconfined yield strength of bulk granular materials and powders. A sample of bulk material is consolidated under controlled pressure in a sample cup with a hole or holes in the bottom. A moveable base smaller than the internal cup dimensions covers the hole(s) to prevent material from escaping the cup and to provide a base for removing the consolidated sample from the cup. After a predetermined time, the consolidated sample is removed from the cup by lifting the base relative to the cup walls through the hole(s) in the bottom of the cup. Once removed from the cup, the strength of the consolidated sample is measured by applying pressure to the top of the sample until the sample breaks. For time tests, the sample is consolidate with weights over predetermined time periods.