Most homemade masks are doing a great job, even when we sneeze, study finds

https://www.eurekalert.org/pub_releases/2020-09/uoia-mhm091820.php

News Release 18-Sep-2020
University of Illinois at Urbana-Champaign, News Bureau

Studies indicate that homemade masks help combat the spread of viruses like COVID-19 when combined with frequent hand-washing and physical distancing. Many of these studies focus on the transfer of tiny aerosol particles; however, researchers say that speaking, coughing and sneezing generates larger droplets that carry virus particles. Because of this, mechanical engineer Taher Saif said the established knowledge may not be enough to determine the effectiveness of some fabrics used in homemade masks.

Saif, a mechanical science and engineering professor at the University of Illinois, Urbana-Champaign, led a study that examined the effectiveness of common household fabrics in blocking droplets. The findings are published in the journal Extreme Mechanics Letters.

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“We found that all of the fabrics tested are considerably effective at blocking the 100 nanometer particles carried by high-velocity droplets similar to those that may be released by speaking, coughing and sneezing, even as a single layer,” Saif said. “With two or three layers, even the more permeable fabrics, such as T-shirt cloth, achieve droplet-blocking efficiency that is similar to that of a medical mask, while still maintaining comparable or better breathability.

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