GENERATION OF TRIBOELECTRIC CHARGE IN TEXTILE FIBER MIXTURES, AND THEIR USE AS AIR FILTERS

Triboelectric exchange between dissimilar polymers on contact can be used to good effect in the construction of air filters because the electric charge on the constituent fibers of filters made in this way attracts dust particles. A study of the sign, magnitude, and lifetime of the charge on such filters has been made, though the methods of investigation are, of necessity, indirect. It has been possible to measure the magnitude of the charge on complete filters only by neutralizing the charge with measured doses of ionizing radiation. Changes in the charge state of a filter can, likewise, only by measured by the effects that they produce on filtration efficiency. Measurements using yarns of the constituent fibers aid our understanding of the charging process, but the lifetime of charge on the yarns is quite different from that on the filter fibres. Results are given of the filtration performance of an optimal mixture, the electric charge on which results in a high filtration efficiency for submicron particles.