An Investigation of Mechanisms of Improving Discharge Particle Flowability in a Smaller Particle Admixing System

Abstract

Particle flowability can be improved by admixing particles smaller than the main particles. However, the mechanism by which this technique improves flowability has not yet fully understood. In the present study, we focused on vibrating discharge particle flowability as one of the type of flowabilities, and we investigated the effects of the main particle roughness created by adhesions of admixed particles on improving the flowability. The main and admixed particles were 41.4, 60.8 μm and 8, 104 nm in diameters, respectively. The main and admixed particles were mixed for various mass ratios, and discharge particle flow rates for the mixed particles were measured. We captured SEM images from 2 different directions and obtained 3-dimensional surface roughnesses by an image analysis software. We calculated RMS roughness values and conducted Fourier Transform analysis for the obtained 3-dimensional surface roughness. As a result, the improving trends of vibrating discharge particle flowability differed from those of compression particle flowability. Furthermore, the main particle roughness conditions showing the most improvement were as follows. RMS roughness value were around 0.1 μm and roughness wavelength were around 3.2 μm.