Surface potential of perforated dielectric layers

Maximum value of the surface potential or related equivalent voltage of perforated dielectric sheets may be of special interest in case of application of such materials like electrostatic-polymeric electret filters, fabrics, nonwovens and others. Experimental investigations carried on polymeric fabrics with application of the corona triode have shown that the surface potential is limited mainly by the back ionisation (back corona) phenomenon. It was also shown, that the corona triode may be a very useful tool for characterisation processes appearing in such materials. Particularly, a simple correlation between maximum value of the surface potential and the threshold voltage of discharge current increase (current flowing through the sample polarised in corona triode system) was found.