EFFECT OF GLIDANT ADDITION ON FLOW-ABILITY OF SOLIDS 493 . Jolnõa•

494 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 561/zm 600-650 650-700 600-650 500-600 400- 500 300-400 200- 300 48/.t.m 90/.t.m trigure &. The effect produced on flow rate by varying the composition of a ternary mixture of magnesia. Flow rates in g rain-1. Orifice diameter 8.98 mm is undesirable in the final product or difficult to handle due to segregation. The addition of small quantities of fine glidants such as A erosil, magnesium oxide and corn starch can be shown to improve the flow properties of mildly cohesive powders (4, 6, 36-38). MECHANISM OF GLIDANT ACTION An improvement in flowability of bulk solids is produced by the addition of many types of glidants and several mechanisms of action may be involved. Frictional effects Since many of the materials used as glidants are also efficient lubricants (1) a reduction of interparticulate friction may be involved. The reduction may take place in two ways. Firsfly, when fine material adheres to the surfaces of an irregular shaped but equidimensional coarse fraction the