What’s the most effective Material for a Mask? Scientists are testing daily items to find 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 during 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 your own home.
READ MORE How to make KN95 Mask For COVID-19 from fabric. Do this D.I.Y. pattern through the Times.
While an easy face covering can reduce the spread of coronavirus by blocking outgoing germs from coughs or sneezes of an infected person, experts say there exists more variation in exactly how much homemade masks might protect the wearer from incoming germs, depending on the fit and excellence of the fabric used.
Scientists round the country have got it upon themselves to identify everyday materials that do a more satisfactory job of filtering microscopic particles. In recent tests, HEPA furnace filters scored well, as did vacuum bags, layers of 600-count pillowcases and fabric much like flannel pajamas. Stacked coffee filters had medium scores. Scarves and bandanna material had the lowest scores, yet still captured a little amount of particles.
If you don’t have some of the materials which were tested, an easy light test can assist you to decide whether a fabric is a good candidate for any mask.
“Hold it up to a 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 can almost view the fibers, it’s not just a good fabric. If it’s a denser weave of thicker material and light doesn’t move through it as a much, that’s the content you need to use.”
Researchers say it’s important to remember that lab studies are conducted under perfect conditions without leaks or gaps in the mask, nevertheless the test methods give us a means to compare materials. And while the level of filtration for a few homemade masks seems low, the majority of us – who are staying home and practicing social distancing in public areas – don’t require the higher level of protection necessary for medical workers. More essential, any face covering is superior to none, especially if worn by a person who has got the virus but doesn’t know it.
The biggest challenge of selecting N95 Masks For COVID-19 is to locate a fabric which is dense enough to capture viral particles, but breathable enough that people can actually wear it. Some items being touted online promise high filtration scores, but the material will be unwearable.
Yang Wang, an assistant professor of environmental engineering at Missouri University of Technology and science, worked with his graduate students to analyze various combinations of layered materials – including both air filters and fabric. “You need a thing that is efficient for removing particles, however, you also have to breathe,” said Dr. Wang, who last fall won an international award for aerosol research.
To check everyday materials, scientists are using methods much like those used to test medical masks, which everybody agrees needs to be saved for medical workers that are exposed to high doses of virus from seeing infected patients. The very best medical mask – referred to as N95 respirator – filters out at the very least 95 percent of particles as small as .3 microns. In contrast, a normal surgical mask – made using a rectangular piece of pleated fabric with elastic ear looPS – includes a filtration efficiency starting from 60 to 80 %.
Dr. Wang’s group tested two types of air filters. An allergy-reduction HVAC filter worked the most effective, 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 discover a filter similar to those tested, choose a minimum efficiency reporting value (MERV) rating of 12 or higher or perhaps a microparticle performance rating of 1900 or higher.
The issue with air filters is they potentially could shed small fibers that would be risky to inhale. So if you want to make use of a filter, you need to sandwich the filter between two layers of cotton fabric. Dr. Wang said certainly one of his grad students made his COVID-19 Face Masks For Sale by using the instructions inside the C.D.C. video, but adding several layers of filter material in a bandanna.
Dr. Wang’s group also found that when 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 %. 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 – however they were less breathable than other options.