Shield those faces: Study says layered masks work better against Kovid-19


Fort Lauderdale, Fla. – They are more comfortable, but they do not work very well.

Plastic face shield, neck gaiter and mask with valves – three of the creative approaches to face coverings since the Kovid-19 hit the United States – are not very effective at stopping the spread of coronovirus particles, Florida Boca Raton according to two new studies at Atlantic University.

FAU engineering researchers tested how well shields and several types of masks worked on mannequins whose fake coughs and sneezes were mapped to determine their way through the air.

Although several studies have shown the effectiveness of covering individual faces, FAU researchers used distilled water and glycerin to simulate particle eruptions from the human mouth, and lasers used striking neon graphics to track drops. be provided. He published his research in the journal Physics Fluid.

Here’s what they found:

Without a mask, the drops traveled more than 8 feet, well ahead of the 6-foot distancing guideline recommended by the US Center for Disease Control and Prevention.

With a bandana, the drops migrated 3 feet, 7 inches; With a folded handkerchief, 1 foot, 3 inches; Two-layer masks of cotton quilt cloth in 70 threads per inch, 2.5 inches; With CVS surgical-grade mask, about 8 inches; And as the N95 mask fit properly, no drops survived.

Plastic face shields prevented large droplets but allowed small particles to bolt from under and around the barrier. Neck gaiters were also not found to be a good road.

Wanted masks, which consist of a disc that opens or closes the wearer as they move in and out, also allow particles to break free.

The best protection came from a cotton mask with at least two layers of fabric, an N95 mask and CVS surgical-grade face coverings.

Professor Manhar Dhanak in FAU’s Department of Ocean and Mechanical Engineering said, scientists tried to find the answer to a problem we all face: how to defend ourselves from coronovirus and be quite comfortable.

“You always wonder how effective your mask is,” said Dhanak. “It was one of our inspirations.”

Dhanak said he was surprised to avoid two-layer masks as well as ill-fitting N95 masks, which do not fit perfectly on some wearers.

“How well it fits on your face is very important,” he said. “They can leak from the sides or into the gap.”

To protect himself, Dhanak said he wears a nanofiber mask similar to an N95, but “lighter and thinner on paper.”

Soon there will be the results of another droplet barrier study at FAU. Dhanak is investigating how newly installed plaxiglass separators, checkout counters and workplaces in schools – are actually protecting the people behind the plastic. Publication is expected in the coming weeks.

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