Synthetic nonwoven materials are well-established filter media to separate particles from gases in automotive, cleanroom, ambient air, healthcare and industrial chemical processing applications. An important effect influencing the filtration efficiency is due to electrostatic charges. Although such electret media have been extensively investigated in the literature, there are still many open questions, concerning e. g. the distribution and long-time stability of the charges on the fibres and the influence of particle loading and environmental conditions.
For efficiency measurements of electret filter media, adequate sodium chloride aerosols with particle diameters in the range of 10 to 1000 nm are generated. A predictable aerosol charge distribution is maintained with an aerosol neutralizer. The next step is to deposit the particles on a defined filter area using a specimen holder. Finally, the deposition rate is measured with an SMPS (Scanning Mobility Particle Sizer) and OPC (Optical Particle Counter) for both, charged and discharged electret fibres in order to quantify the influence of electric effects on the filtration efficiency. The measurement and evaluation of the filtration efficiency...
Session: G8 - Modelling and Simulation I
Day: 12 October 2016
Time: 10:45 - 12:00 h