Characterization of two electrode systems for corona-charging of non-woven filter media

The aim of this paper is to provide a better understanding of the corona-charging process of non-woven electret filters for automotive and medical applications. The experiments were performed on polypropylene samples: 500-μm-thick non-woven fabrics (fiber diameter: 24 μm), laid on a grounded plate electrode and subjected to positive or negative corona generated either by a dual wire–cylinder electrode or by a triode-type electrode set. The paper reports the results of current–voltage characteristics measurements, as well as the repartition of the current density at the surface of the grounded electrode.