Good news. These homemade face masks work – and they may even be more breathable than medical masks, a recent study shows. The results were published in Extreme Mechanics Letters.
Because the supply of professional and medical face masks is limited, the Centers for Disease Control and Prevention (CDC) have recommended that people make their own face coverings out of fabric to help slow the spread of COVID-19.
Several studies have already shown that household substances can help block tiny aerosol particles, but coughing, sneezing, and speaking create larger droplets. However, masks must be comfortable and allow easy breathing so they can be worn evenly, the researchers found. “A mask made from a material with low breathability is not only uncomfortable, but can also lead to leaks, as the exhaled air is pressed around the contours of a face, which defeats the purpose of the mask and creates a false sense of protection,” said Co -Author Taher Saif, PhD, in a press release. “Our goal is to show that many common fabrics take advantage of the trade-off between breathability and efficiency when blocking droplets – large and small.” Dr. Saif is a professor of mechanical engineering and engineering at the University of Illinois, Urbana-Champaign.
There is no agreed definition that distinguishes “aerosols” from “droplets”. Previous studies on cloth masks have mainly focused on the filtration efficiency of household fabrics against aerosol particles between 10 nanometers and 10 micrometers in diameter. This is really small: consider that there are 1 million nanometers and 1,000 micrometers in just one millimeter. (And a millimeter is itself a thousandth of a meter.)
11 common household substances
Researchers looked at how 11 common household items act as a barrier compared to a commercial medical mask.
The fabrics tested varied between new and used, 100% cotton, cotton blends and plastics. They were tested in single shifts and doubled and tripled. All of these materials have been found to be considerably effective in blocking high velocity droplets, even as a single layer. They also found that 2 layers of highly permeable material, such as B. a T-shirt, droplets up to 94% and medical masks can block while they are about twice as breathable.
But don’t just rely on the fabric
However, the researchers emphasized that the performance of a cloth mask also depends on how it is worn and how much air can escape through the gaps. The masks should fit snugly around your mouth and nose and fastened under your chin. Elastic bands or ties are personal preference but should be tied properly.
How you use your mask is also important. Wash your hands before putting it on and hold it by the ties or elastic bands. When removing, avoid touching the fabric and handle only the ties or elastic bands.
Finally, it is important that you wash your masks properly and frequently. The researchers found that household fabrics are “more permeable” than medical masks. This means that virus drops can penetrate a homemade face mask and stay there longer. Hence, they have to be washed frequently to decontaminate them.
Social media shows that many people at home started making masks for themselves and for others. But they’re not difficult to make if you have a needle, thread, and fabric. Many institutions have published guides on how to cut and sew your own homemade face masks, including the CDC, Johns Hopkins University, and Vanderbilt University.
Using home-made masks can have another benefit. The researchers’ results suggest that masks made from washable materials like cotton help reduce the environmental impact of disposable, non-biodegradable masks.
Sydney Shaw is an award-winning writer, editor, and digital producer. She lives in New Jersey with her cat Oliver.