Assessing effectiveness and comfortability of a two-layer cloth mask with a high-efficiency particulate air (HEPA) insert to mitigate COVID-19 transmission

A face mask is essential personal protective equipment to mitigate the spread of COVID-19. While a cloth has least ability prevent passage infectious respiratory droplets through it compared surgical and N95 masks, does not fit snugly causes significant air leakage. The synthetic fibers in latter reduce comfortability are an allergen for facial eczema. Moreover, CO 2 inhalation reduces heat transfer nose. Therefore, objective present work improve effectiveness two-layer by introducing intermediate, high-efficiency particulate (HEPA) filter layer. volume impacted penetrates single-layer mask, ejecting secondary from rear side. However, prevents this ejection. Despite slowing down liquid penetration, capillary imbibition due its hydrophilicity transport into second layer, resulting thin-liquid layer at mask's rear-side surface contaminating it. Conversely, HEPA inserted imbibition, making free contamination. We attribute impedance intermediate hydrophobic characteristics. experimentally analytically assess role wettability on imbibition. breathability measurements masks show that mask.