Filtration and Breathability of Nonwoven Fabrics Used in Washable Masks

We consider fabrics that can improve upon the performance of widespread all-cotton mask, and examines effect layering, machine washing drying on their filtration breathability. Individual materials were evaluated for quality factor, Q, which combines efficiency Filtration was tested against particles 0.5 ?m to 5 aerodynamic diameter. Nonwoven polyester nonwoven polypropylene (craft fabrics, medical masks, wraps) showed higher factors than woven (flannel cotton, Kona sateen cotton). Materials with meltblown filtered best, especially submicron particles. Subsequently, we combined high performing into multi-layer sets, evaluating sets’ before after our protocol, included washing, drying, isopropanol soak. Sets incorporating designed degraded significantly post-wash in range where they excelled prior (Q > 50 kPa-1 at 1 ?m, respectively, Q < 10 post-wash). Washing caused lesser degradation sets spunbond non-woven or wraps = 12 24 pre-wash, 8 Post-wash are similar all this study, quilting cotton 6). Washed 12% 42% 27% 76% 58% 96% 2.8 72% 100% 4.2 ?m. The measured pressure drop both homogeneous heterogeneous fabric combinations agreed estimations from a model assuming layers filter independently. Further examination selective nonwovens IPA filtration, while produced variable effects filtration. Variability observed across Filti samples.