Patent ID: 8853583

Claim:
A method for separating a synthetic material in granular form from a loose mass of various synthetic materials, the method comprising: conveying a measured quantity of a granular mass along a trajectory comprising a rubbing surface, subjecting the measured quantity of the mass falling down from the rubbing surface to an electrical field, collecting at least one of the masses of granules separated by the electrical field wherein the measured quantity of the mass is made to advance in a single layer on the rubbing surface, while maintaining the single layer into contact with the rubbing surface the rubbing surface being subjected to repeated acceleration in opposite directions contained in the plane of the rubbing surface, or tangential thereto to move the mass on the surface in order to improve the electrostatic charge, the rubbing surface being clad with, or made of, a material having triboelectric properties which are intermediate with respect to triboelectric properties of the granular mass, wherein the rubbing surface is clad with or made of a same material as a material which it is intended to separate from the mass.