Motion of a conductive particle in viscous fluid simulating liquefied plastic waste

Abstract

When plastic waste is liquefied for recycling, the impurities included inside would influence on the quality of reproduction. As a fundamental study to seek a suitable way to remove solid impurities by means of an electrostatic force, the motion of spherical conductive particles under a uniform electric field has been carefully investigated, simulating impurity in viscous liquefied plastics. Experimental results indicated that the particle repeats up-and-down motion between the parallel electrodes. The particle motion can be divided into four modes: settling on the lower electrode; moving upward; settling on the upper electrode; and moving downward. The higher the applied voltage is, the faster the average particle velocity and the shorter resting time can be obtained. The settling could be explained by the fact that there is a liquid flow induced by the particle motion and it pushes the particle against the electrode until the flow decreased. At the electrode edge, curved motion of the particle was observed. The curvature of the locus of the particle in upward motion is larger than that in downward.