Continuous Operation of a Tribo-Electrostatic Separator for the Recovery of PET Fibers from Industrial Wastes

This study presents the experimental evaluation of a continuous-mode tribo-electrostatic separator (TES) for the recovery of polyethylene terephthalate (PET) fibers from complex industrial waste. Within the scope of the European WhiteCycle project, the separator was tested on two representative waste streams: shredded end-of-life tires (ELT) and industrial hoses (ELH). The influence of key parameters—cylinder inclination, rotation speed, and screw feeder rate—was assessed. Results show that a 4° inclination combined with a screw speed corresponding to position 6 of the potentiometer enables stable continuous operation. Maximum fiber productivity reached 1.5 kg/h with ELH (double-shredded), while ELT remained limited to 0.26 kg/h. The purity exceeded 80% in both cases. Limitations were observed due to agglomeration and incomplete tribocharging. The study highlights promising avenues for industrial scale-up by integrating mechanical preconditioning and hybrid separation strategies.