During the Covid-19 pandemic, cloth face masks became a way to help protect from the virus.

For some people, they became a fashion statement, with many fabric choices available. But just how effective are they, especially in blocking respiratory droplets from a sneeze?

Researchers from the University of New South Wales used high-speed videos of a person sneezing to identify the optimal cloth mask design.

A healthy 30-year-old volunteer donned each mask, tickled the inside of his nose with tissue paper on a cotton swab, and then readjusted the mask just before the onset of a sneeze.

The researchers captured high-speed videos of the sneezes and computed the intensity of droplets in the images in a region 2 cm from his mouth. With each fabric layer, the droplet-blocking capability improved by more than 20-fold.

Interestingly, all of the three-layer cloth combinations the researchers tested were more effective than a three-layer surgical mask.

The best masks for blocking droplets contained a hydrophilic inner layer of cotton or linen, an absorbent middle layer of a cotton/polyester blend and a hydrophobic outer layer of polyester or nylon.

The findings are detailed in the journal ACS Biomaterials Science & Engineering.

Future studies are planned with more people and different age groups, said researchers including Shovon Bhattacharjee, from the UNSW.

Face masks help reduce disease spread by blocking tiny, virus-laden droplets expelled through the nose and mouth when a person speaks, coughs or sneezes.

(This story was published from a syndicated feed. Only the headline and picture has been edited by FIT)