Abstract
To determine the grain shape of silica sand, W. Davies and W. J. Rees have established the method of air permeability and J. Kashima has also built up the method by means of a centrifuge. These are truely very precise methods to the determination of sand grain shape, but there leave some difficulties to apply the methods in foundry practices. Therefore, the authors worked out a new method of determining sand grain shape by using a permeability meter.
The apparatus and attachment are illustrated in Fig. 1.
The results of the determination are as follows :
1) The method by means of permeability meter seems satisfactory in the points of precision and easiness of the determination.
The coefficient of angularity of a glass ball used for day-light screen (20∼200 mesh) is 1.02 and the problable error is ±0.01.
2) The coefficients of angularity of the silica sands yielded in Seto, Tokitsu and Mikawa were almost the same values with Isono's experiment.
