Tribo-charging Characteristics of Poly-styrene with varying BFR Concentrations in view of Electrostatic Separation from Mixed Granular Waste Plastics

Tribocharging of polymer granules is a particularly useful technique for safe and efficient material segregation in waste electrical and electronic equipment (WEEE) recycling. This study aims at examining the triboelectric charging characteristics of polystyrene (PS) granules with varying Brominated Flame Retardant (BFR) concentrations (namely, 0%, 0.23% and 4.6%). The samples were stored under controlled environmental conditions, specifically (24°C, 30% relative humidity (RH)) and neutralised using an air-ioniser. Following this, they were charged using mechanical agitation using a siever shaker inside a stainless steel container within a Faraday pail. The readings were taken with a Keithley electrometer over 40–45 minutes, with each experiment conducted three times for each set of granules for reliability. The results confirm the previous experiments about the net behaviour of the granules, showing that PS granules with higher BFR concentration store a higher charge. These results offer insights into enhancing polymer segregation procedures and raising the effectiveness and safety of WEEE recycling programs.