What’s the Best Material for a Mask? Scientists are testing daily items to get the best protection from coronavirus. Pillow cases, flannel pajamas and origami vacuum bags are all candidates. Federal health officials have recently recommended that we cover our faces with fabric through the coronavirus pandemic. But what material supplies 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 Steps to make KN95 Mask Sale from fabric. Try this D.I.Y. pattern from 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 is certainly more variation in just how much homemade masks might protect the wearer from incoming germs, depending on the fit and quality of the material used.
Scientists around the country have got it upon themselves to recognize 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 cheapest scores, but nonetheless captured a little percentage of particles.
If you don’t have the materials which were tested, a basic light test can enable 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 also can almost see the fibers, it’s not really a good fabric. If it’s a denser weave of thicker material and light doesn’t move through it as being much, that’s the fabric you need to use.”
Researchers say it’s important to remember that lab studies are conducted under perfect conditions without leaks or gaps inside the mask, nevertheless the test methods provide us with a means to compare materials. And while the degree of filtration for a few homemade masks seems low, many of us – that are staying home and practicing social distancing in public – don’t need the high level of protection required for medical workers. More essential, any face covering is superior to none, particularly if worn by a person who has got the virus but doesn’t know it.
The largest challenge of deciding on N95 Masks For COVID-19 is to discover a fabric that is dense enough to capture viral particles, but breathable enough we can actually use it. Some items being touted online promise high filtration scores, however the material would be unwearable.
Yang Wang, an assistant professor of environmental engineering at Missouri University of Science and Technology, dealt with his graduate students to learn various mixtures of layered materials – including both air filters and fabric. “You need a thing that is efficient for removing particles, however you should also breathe,” said Dr. Wang, who last fall won a global award for aerosol research.
To check everyday materials, scientists are utilizing methods similar to those used to test medical masks, which everybody agrees should be saved for medical workers that are exposed to high doses of virus from seeing infected patients. The best medical mask – referred to as N95 respirator – filters out a minimum of 95 percent of particles no more than .3 microns. In comparison, a normal surgical mask – made employing a rectangular piece of pleated fabric with elastic ear looPS – includes a filtration efficiency starting from 60 to 80 percent.
Dr. Wang’s group tested 2 kinds of air filters. An allergy-reduction HVAC filter worked the 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 achieve 95 percent. To discover a filter similar to those tested, search for a minimum efficiency reporting value (MERV) rating of 12 or higher or perhaps a microparticle performance rating of 1900 or higher.
The problem with air filters is they potentially could shed small fibers that would be risky to inhale. So in order to use a filter, you need to sandwich the filter between two layers of cotton fabric. Dr. Wang said among his grad students made his N95 Face Mask For Sale by using 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 whenever certain common fabrics were utilised, 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 2 layers, and 48.8 percent in four layers. A 100 percent dkbeiy bandanna did the worst, capturing only 18.2 percent when doubled, and just 19.5 percent in four layers.
The group also tested Brew Rite and Natural Brew basket-style coffee filters, which, when stacked in three layers, showed 40 to 50 percent filtration efficiency – but they were less breathable than other options.