New Electrostatic Separator with Tribo-Charged Insulating Roll

This study presents an experimental investigation of a novel tribo-electrostatic separator, currently patent-pending, which enables plastic particles separation without the use of a high-voltage power supply. The system relies on a tribo-charging mechanism where a PVC rotating roll is charged through continuous contact with a secondary charging roll. The charged PVC roll then generates an electric field that facilitates the separation of plastic mixtures based on their triboelectric properties. Experiments were conducted using a granular mixture of polyvinyl chloride (PVC) and polymethylmethacrylate (PMMA) to determine the optimal operational parameters. The results show that a rotation speed of 1350 rpm for the charging roll significantly enhances the electrical potential acquired by the separation roll, leading to stronger electrostatic forces and more efficient separation. The tribo-electric treatment time of particles also plays a key role, with 4 minutes identified as the optimal duration for maximizing performance. Under these optimal conditions (1350 rpm, 4 min), the recovery rates reached 93 % for PMMA and 96 % for PVC, while the purity levels attained 96 % for PMMA and 98 % for PVC. These results demonstrate the effectiveness of the new separator and its ability to significantly improve both recovery and purity compared to conventional approaches. Overall, the findings confirm the efficiency and industrial relevance of this innovative separator, offering a promising alternative to conventional high-voltage-based systems for plastic waste valorization.