What’s the most effective Material for a Mask? Scientists are testing daily items for the greatest defense against coronavirus. Pillow cases, flannel pajamas and origami vacuum bags are all candidates. Federal health officials have finally recommended that we cover our faces with fabric through the coronavirus pandemic. But what material provides the most protection?
The Centers for Disease Control and Prevention has posted a no-sew mask pattern using a bandanna along with a coffee filter as well as being a video on making masks using rubber bands and folded fabrics found at home.
READ MORE How to make KN95 Mask Sale from fabric. Use this D.I.Y. pattern from the Times.
While a simple face covering can lessen the spread of coronavirus by blocking outgoing germs from coughs or sneezes of your infected person, experts say there is certainly 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 took 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 similar to flannel pajamas. Stacked coffee filters had medium scores. Scarves and bandanna material had the lowest scores, but nonetheless captured a tiny amount of particles.
If you don’t have the materials that were tested, a simple light test can assist you to decide whether a fabric is a great candidate for a 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 with the fibers and you 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 pass through it as much, that’s the material you want to use.”
Researchers say it’s important to remember that lab studies are conducted under perfect conditions with no leaks or gaps inside the mask, however the test methods give us a way to compare materials. And while the degree of filtration for many homemade masks seems low, many of us – that are staying home and practicing social distancing in public areas – don’t have to have the higher level of protection necessary for medical workers. More important, any face covering is preferable to none, particularly when worn by a person who provides the virus but doesn’t know it.
The biggest challenge of selecting N95 Masks For COVID-19 is to discover a fabric that is certainly 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 Science and Technology, worked with his graduate students to study various mixtures of layered materials – including both air filters and fabric. “You need something which is efficient for removing particles, but you also need 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 that 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 utilizing a rectangular bit of pleated fabric with elastic ear looPS – includes a filtration efficiency starting from 60 to 80 percent.
Dr. Wang’s group tested two 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 accomplish 95 percent. To locate a filter much like those tested, search for 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 might be risky to inhale. So in order to make use of a filter, you have to sandwich the filter between two layers of cotton fabric. Dr. Wang said one of his grad students made his COVID-19 Face Masks For Sale by following the instructions in the C.D.C. video, but adding several layers of filter material within a bandanna.
Dr. Wang’s group also found that when certain common fabrics were utilised, two layers offered much 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 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 % filtration efficiency – however they were less breathable than other choices.