High-quality and easy-to-regenerate personal filter

PLoS One. 2022 Jun 8;17(6):e0268542. doi: 10.1371/journal.pone.0268542. eCollection 2022.

Abstract

Proper respiratory tract protection is the key factor to limiting the rate of COVID-19 spread and providing a safe environment for health care workers. Traditional N95 (FFP2) respirators are not easy to regenerate and thus create certain financial and ecological burdens; moreover, their quality may vary significantly. A solution that would overcome these disadvantages is desirable. In this study a commercially available knit polyester fleece fabric was selected as the filter material, and a total of 25 filters of different areas and thicknesses were prepared. Then, the size-resolved filtration efficiency (40-400 nm) and pressure drop were evaluated at a volumetric flow rate of 95 L/min. We showed the excellent synergistic effect of expanding the filtration area and increasing the number of filtering layers on the filtration efficiency; a filter cartridge with 8 layers of knit polyester fabric with a surface area of 900 cm2 and sized 25 × 14 × 8 cm achieved filtration efficiencies of 98% at 95 L/min and 99.5% at 30 L/min. The assembled filter kit consists of a filter cartridge (14 Pa) carried in a small backpack connected to a half mask with a total pressure drop of 84 Pa at 95 L/min. In addition, it is reusable, and the filter material can be regenerated at least ten times by simple methods, such as boiling. We have demonstrated a novel approach for creating high-quality and easy-to-breathe-through respiratory protective equipment that reduces operating costs and is a green solution because it is easy to regenerate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerosols
  • COVID-19* / prevention & control
  • Equipment Design
  • Filtration / methods
  • Humans
  • Masks
  • Materials Testing / methods
  • Polyesters
  • Respiratory Protective Devices*

Substances

  • Aerosols
  • Polyesters

Grants and funding

LM2018103: MF, MK, ZZ, JH, BP, PH, SS, JP, MV LM201822, VI04000048: JO, OM, JK, VZ This work was supported by the Ministry of Youth, Education and Sports of the Czech Republic (projects no. LM2018103 and LM201822). and Ministry of Interior of the Czech Republic, project No. VI04000048. http://www.msmt.cz/?lang=2https://www.mvcr.cz/mvcren/ The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.