MEASUREMENT OF THE ADHESIVE FORCE BETWEEN PARTICLES AND A SUBSTRATE BY MEANS OF THE IMPACT SEPARATION METHOD - EFFECT OF THE SURFACE-ROUGHNESS AND TYPE OF MATERIAL OF THE SUBSTRATE

In order to study the effect of surface roughness and substrate materi al type on the adhesion of particles, measurements were made using the pendulum impact separation method using a variety of powders and subs trates. Two methods were used to attach powder particles to a substrat e: the free falling method and the fluidized method. When the powders were deposited on a substrate by free falling (with negligible force), the force of adhesion to the substrate with a rough surface was less than the adhesion to the smooth surface substrate. The degree of reduc tion in adhesive force increased as the shape of sample powder more cl osely resembled a sphere. When the powders were attached to a substrat e under a fluidized state, a remarkable increase in adhesive force was observed in organic powder/polyvinyl chloride (PVC) systems. This is probably due to the electrostatic force produced by the collision and/ or friction of particles to the PVC sheet.