ELECTROSTATIC CONTRIBUTION TO POWDER-PARTICLE ADHESION

Experiments are described which examine the electrostatic contribution to the adhesion of powder particles to substrates. The fine powder in these experiments was dispensed over the large surface area of an assembly of glass beads and the adhesion of the particles to the larger beads was measured with a centrifuge. Complementing the adhesion measurements were charge measurements where the average charge density and also the incremental charge density were measured by gradually blowing the powder from the beads. A purely electrostatic point-charge model for the adhesion of the particles was consistent with the observations in most cases. In some situations, however, an additional term was needed to better describe the adhesion, and this may have been either an electrostatic multipole phenomenon or a van der Waals contribution. © 1969 The American Institute of Physics.