Mechanical Packing of Spherical Particles

Abstract

An idealized experimental study of particle packing was made. Spherical metal shot of several discrete, narrow size ranges was efficiently packed in glass containers by mechanical vibration. Packing arrangements and the dynamic process of packing were studied visually. One‐size spheres packed in an orthorhombic arrangement with a density 62.5% of theoretical density. Forming of high‐density multicomponent packings was shown to require at least a sevenfold difference between sphere sizes of the individual components. A quaternary packing with a density 95.1% of theoretical density was formed from spheres with diameter ratios 1:7:38:316 and volume compositions 6.1:10.2:23.0:60.7%, respectively. Such packings could be poured from their glass containers, thus proving that effective mechanical packing is simply an efficient arrangement of spheres of prescribed sizes and proportions. The significance and utility of this work to the ceramic and other industries is discussed.