Tribocharging of plastics granulates in a fluidized bed device

The paper presents a modular fluidized bed device for the study of plastics tribocharging and electrostatic separation, with application in the field of plastic recycling. Evaluation of the device in independent operation for charge-to-mass ratio measurements pointed out the different triboelectric behaviour of six tribocharging chambers made of plastic (PVC, PP, PET, PE, PMMA) and aluminium. The electrostatic separation tests carried out on PET and PVC granulates confirmed the effectiveness of the fluidized bed tribocharging device integrated in a free fall separator. They pointed out three charging mechanisms by particle/particle and particle/walls collisions.