Packing density or bulk density depends on grit size and shape. For example, equidimensional shapes pack to a higher bulk density than flat shapes [MENA00]. The packing density is a rather simple but effective measure for the dominant grit shape of a batch, if grit size and size distribution are known [MALK08, SCHT81].
Measurement procedures for the packing density of conventional abrasive grits are defined in ISO 9136, parts 1 and 2, or ANSI B74.4 [MENA00]. ANSI B74.17 specifies the packing density for superabrasives [MENA00]. One method is to determine the weight of grits required to fill a cylinder of known volume when the grits are allowed to flow through a funnel and fall from a fixed height [ANSI92]. The packing density is given in (kg/l), (g/l) or (g/cm3) [SCHT81, ANSI92].
220.127.116.11 Shape Sorter
The shape sorter, also called vibration table (German “Rtitteltisch”) consists of an inclinated table, which by oscillating causes the abrasive grits to move up or down depending on their shape. Boxes at the edge of the table collect the different shape fractions. Diamonds are sorted from cubic crystals and cubooctahedrons to broken particles of irregular shapes, such as needle-like crystals or platelets. The principle works only for batches of the same grit size range [VOLL10, LINK15].