Tohei Yokoyama

Measurement of the tensile strength of a powder bed by a swing method measuring instrument

Abstract The measurement of the tensile strength of a powder bed has been carried out by means of the swing method measuring instrument, which has been developed by the authors. The effects on the void fraction and the moisture content have been investigated. From the stress—displacement curves obtained directly with this instrument, the work required for the tensile breakage of the powder bed was calculated. The most interesting problem is the application of the measurement of tensile stress to the design of powder treatment processes. The floodability of fine powders has been discussed empirically but theoretical bases are not sufficient for the evaluation of the potential floodability. The following dimensionless number, namely the ratio of the cohesive force to the gravity force on a single particle, was found to give a good correlation with the empirical floodability index evaluated by Carrs method.