On the triboelectrically charged nonwoven electrets for air filtration

This work deals with development, characterization, and application of triboelectrically charged nonwoven electrets. The electrets were prepared using wool and polypropylene fibers and employing needlepunched nonwoven technology. It was observed that the magnitude and duration of electret charge increased with a decrease in diameter of wool and polypropylene fibers. The charge was found to decay double exponentially, presumably due to quick decay of surface charge and slow decay of bulk charge. The charge in tribocharged electrets was utilized to capture hazardous particles from the air stream very efficiently. The electret media exhibited remarkably higher filtration efficiency than the uncharged media.