Electret filter media are commonly used in aerosol filtration to remove particles from gases. They provide a high initial particle removal efficiency combined with a low pressure drop as the fibers of the electret filter media are electrostatically charged. In addition to the mechanical deposition mechanisms (diffusion, impaction and interception), charged particles are deposited by the Coulomb effect and any (charged or uncharged) particles by dielectrophoresis. However, the particle deposition is reduced with increasing exposure time, since already deposited particles can either neutralize or shield the electrostatic charge of the microfibers and thus weaken the above-mentioned electrostatic effects.

In this work the experimental investigations of the loading-dependent particle deposition are performed exposing electret filter media to...