A measurement method for testing textile materials charging for self-charging electrostatic face masks application

Abstract

Electrostatic masks are significantly more effective than conventional mechanical masks due to their enhanced filtration efficiency. The charge of filtering textiles is generated by friction between two layers due to the spontaneous movement of the mask under wearing. However, the filtrating efficiency is diminished over time as the electrostatic charge decays, especially in humid environments. An essential requirement would be to compare the filling properties of various textiles used for masks by reliable measurement to produce more effective masks. However, no standardized procedure exists for measuring the charge of textiles. In this paper, a new test arrangement and protocol were developed to measure textiles’ charging due to friction accurately is presented. The new test system is built up from a stationary sample holder and a movable element holding another sample to simulate friction between the layers and ensure the measurement repeatability. The surface charge of tested textiles was measured using a parallel plane electrode system positioned 0.5 cm above the textile, connected to a high-impedance voltmeter. The tested textiles’ initial charging can be determined by measuring the voltage of plane electrode. The results demonstrate that the newly developed test setup enables testing the charging capabilities of various mask filters and ensuring the comparability of various textile materials.