Patent ID: 6426474
Filing Date: 2002-07-30
Classification: B03C,B29B,B29K,Y02W

Abstract:
A plastic sorting method, in which plastic pieces (1) comprising a plurality of types of plastic pieces which have been crushed into a granular shape and mixed together are introduced into and agitated in a frictional charging device (3) so that the plastic pieces (1) are frictionally charged with a polarity and amount of charge that correspond to the types of plastic pieces, and then a specified type of plastic piece (1) is recovered by collecting the plurality of types of plastic pieces (1) with an electrostatic separation unit (G) in separate separation containers depending on polarity and amount of charge, the plastic sorting method being characterized in that:in the frictional charging device (3), the plastic pieces (1) are agitated and frictionally charged in a container (11) by the relative motion between a plurality of agitating rod members (19) that are radially attached to a rotation shaft (18) rotating about the center of the container (11) and a plurality of auxiliary agitation members (27) that are fixed to an inner container (13) and arranged between the agitating rod members (19); and the surface area of the agitating rod members (19) and the auxiliary agitation members (27) is at least 10% of the total surface area of the plastic pieces (1) that are introduced into the frictional charging device (3) at one time.