Home / Health / The best material and shape for the DIY mask? Quilted cotton beats the bandana, says a new study

The best material and shape for the DIY mask? Quilted cotton beats the bandana, says a new study

Florida Atlantic University researchers experimented with different materials and styles of non-medical masks and found that a well-made stitched mask with two layers of quilted fabric was the most effective in stopping the spread of droplets from cough and emulated sneezing.

They also compared a slightly bent homemade face mask, such as the one you could make with a handkerchief or T-shirt, a bandana-style face cover and a non-sterile cone commercial mask that is usually available at the pharmacy.

The researchers said they chose to test these face coating styles because they are readily available to the public and do not stray from providing medical-grade masks and respirators for healthcare professionals.

“While there are some previous studies on the effectiveness of medical-grade equipment, we do not currently have much information about the fabric-based coatings that are more accessible to us,”

; said Siddhartha Verma, assistant professor in the ocean engineering department and Florida Atlantic University mechanic and author of the study.

With the stitched cotton mask, the droplets traveled 2.5 inches.

“Our hope is that the visualizations presented in the document will help communicate the rationale behind the recommendations for social distancing and the use of face masks.”

The study published Tuesday in the journal Physics of Fluids.

The World Health Organization says governments should encourage people to wear non-medical tissue masks, particularly in environments where physical spacing of at least 1 meter is not possible, such as on public transportation, in shops or in other places. confined or crowded environments.
In the United States, the Centers for Disease Control and Prevention recommend cloth coverings to protect others in places where social distances cannot be maintained.

Emulation of coughing and sneezing

In the experiment, a manikin’s head was padded inside to emulate a person’s nasal passages and mounted at a height of 5 ‘8 “to approximate the height of an adult male. The researchers” freed ” sneezing or coughing using a hand pump and a smoke generator.

With a folded cotton handkerchief, the droplets traveled 1 foot, 3 inches

They then used a laser to detect the droplets as they were coughed and sneezed from the mannequin’s head, mapping the droplet paths and examining how different designs and materials alter that path.

The main challenge for researchers was how to faithfully simulate a cough and sneeze.

“The setting we used (is) a simplified cough, which is actually complex and dynamic,” said Verma in a note.

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They found that the droplets of a simulated uncovered cough were able to travel more than 8 feet; with a bandana they walked 3 feet, with a folded cotton handkerchief, they walked 1 foot, 3 inches; and with the cone mask, the droplets traveled about 8 inches. With the sewn quilted mask, they traveled 2.5 inches.

“We found that although unobstructed turbulent jets were observed traveling up to 12 feet, most of the expelled droplets fell to the ground at this point,” said Manhar Dhanak, a professor in Florida’s Department of Ocean and Mechanical Engineering Atlantic University and coauthor of the study.

“It is important to emphasize that both the number and concentration of the droplets will decrease with increasing distance, which is the fundamental logic behind social distancing.”

With the cone mask, the droplets traveled about 8 inches.

Higher thread counting alone was not more effective, the researchers said. In their experiment, the bandana had the highest count and was the least effective.

They claimed that their experiment could help healthcare professionals, medical researchers and manufacturers assess the effectiveness of facial masks.

WHO recommends washing your hands before touching a mask, making sure it is not too loose and covers your mouth and nose. He says you should put it in a clean bag if you plan to reuse it and wash it every day with soap and hot water.

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