Effect of the applied high voltage on the neutralization efficiency of negative charges accumulated on polypropylene film surface

In this study, experimental characterizations obtained by non-contact measurements of the profile and decay of the surface potential have been carried out. The experiments were performed on polypropylene (PP) films (50 mm × 25 mm). The samples were charged for duration of 5 seconds in ambient air of temperature and relative humidity, using a negative polarity dc corona triode electrode system (needle-grid-plate configuration). The study investigates the impact of the charging voltage on the surface potential profile and decay, with varying values of the grid voltage. The accumulated charges on the samples surface were neutralized by a sinusoidal alternating corona discharge generated at power frequency of 50 Hz. This neutralization process was performed after the charging procedure, where the samples move within the ac corona discharge zone. The effect of the applied high voltage on the neutralization of electric charges was studied. The evaluation of neutralization efficiency was evaluated by the comparison of surface electric potential profiles before and after neutralization in a static mode. The experimental results obtained indicate that higher applied high voltage induces better neutralization efficiency.