What’s the Best Material for a Mask? Scientists are testing daily items to get the best defense against coronavirus. Pillow cases, flannel pajamas and origami vacuum bags are candidates. Federal health officials have recently recommended that we cover our faces with fabric throughout the coronavirus pandemic. But what material provides the most protection?
The Centers for Disease Control and Prevention has posted a no-sew mask pattern employing a bandanna along with a coffee filter as well as a video on making masks using rubber bands and folded fabrics found in the home.
READ MORE How to make Face Masks For Coronavirus Sale from fabric. Do this D.I.Y. pattern through the Times.
While an easy face covering can decrease the spread of coronavirus by blocking outgoing germs from coughs or sneezes of an infected person, experts say there is more variation in exactly how much homemade masks might protect the wearer from incoming germs, depending on the fit and excellence of the material used.
Scientists around the country have taken it upon themselves to distinguish everyday materials that do a better job of filtering microscopic particles. In recent tests, HEPA furnace filters scored well, as did vacuum bags, layers of 600-count pillowcases and fabric comparable to flannel pajamas. Stacked coffee filters had medium scores. Scarves and bandanna material had the cheapest scores, yet still captured a tiny portion of particles.
If you don’t have some of the materials which were tested, a basic light test can help you decide whether a fabric is a good candidate to get a mask.
“Hold it up to and including bright light,” said Dr. Scott Segal, chairman of anesthesiology at Wake Forest Baptist Health who recently studied homemade masks. “If light passes really easily through the fibers and you also can almost begin to see the fibers, it’s not just a good fabric. If it’s a denser weave of thicker material and light doesn’t go through it as much, that’s the material you would like to use.”
Researchers say it’s important to understand that lab studies are conducted under perfect conditions with no leaks or gaps in the mask, nevertheless the test methods give us a way to compare materials. And even though the level of filtration for a few homemade masks seems low, most of us – who are staying home and practicing social distancing in public – don’t need the high level of protection necessary for medical workers. More essential, any face covering is preferable to none, particularly when worn by a person who has got the virus but doesn’t know it.
The largest challenge of deciding on COVID-19 Masks For Sale is to locate a fabric that is dense enough to capture viral particles, but breathable enough we can actually wear it. Some items being touted online promise high filtration scores, but the material could be unwearable.
Yang Wang, an assistant professor of environmental engineering at Missouri University of Technology and science, worked with his graduate students to study various combinations of layered materials – including both air filters and fabric. “You need something that is efficient for removing particles, however, you also have to breathe,” said Dr. Wang, who last fall won a worldwide award for aerosol research.
To check everyday materials, scientists are utilizing methods comparable to those used to test medical masks, which everybody agrees needs to be saved for medical workers who are exposed to high doses of virus from seeing infected patients. The most effective medical mask – called the N95 respirator – filters out at the very least 95 percent of particles as small as .3 microns. In comparison, an average surgical mask – made using a rectangular piece of pleated fabric with elastic ear looPS – features a filtration efficiency ranging from 60 to eighty percent.
Dr. Wang’s group tested 2 kinds of air filters. An allergy-reduction HVAC filter worked the very best, capturing 89 percent of particles with one layer and 94 percent with two layers. A furnace filter captured 75 percent with two layers, but required six layers to attain 95 percent. To find a filter similar to those tested, choose a minimum efficiency reporting value (MERV) rating of 12 or higher or a microparticle performance rating of 1900 or higher.
The issue with air filters is they potentially could shed small fibers that could be risky to inhale. So in order to make use of a filter, you need to sandwich the filter between two layers of cotton fabric. Dr. Wang said among his grad students made his Best COVID-19 Masks Sale by following the instructions in the C.D.C. video, but adding several layers of filter material in a bandanna.
Dr. Wang’s group also found that if certain common fabrics were used, two layers offered less protection than four layers. A 600 thread count pillow case captured just 22 percent of particles when doubled, but four layers captured nearly 60 percent. A thick woolen yarn scarf filtered 21 percent of particles in two layers, and 48.8 percent in four layers. A 100 % dkbeiy bandanna did the worst, capturing only 18.2 percent when doubled, and just 19.5 percent in four layers.
The audience also tested Brew Rite and Natural Brew basket-style coffee filters, which, when stacked in three layers, showed 40 to fifty percent filtration efficiency – but they were less breathable than other available choices.