They’re made of cotton. Or polyester. Or paper. Or polypropylene. Here’s what researchers say about the effectiveness of the different types of face masks during this pandemic.
Read full story at source: >A User’s Guide To Masks: What Types Offer The Best Protection? : Goats and Soda : NPR
“Face masks can also offer the wearer some protection — though how much varies greatly, depending on the type of mask. No mask will offer full protection, and they should not be viewed as a replacement for physical distancing of at least 6 feet from others, frequent hand-washing and avoiding crowds. When you combine masks with those measures, they can make a big difference.
“…consider the fabric itself. The tightness of the weave is really important. … To check your fabric, hold it up to a light: If you can easily see the outline of the individual fibers, it’s not going to make a great filter. Researchers say a thick 100% cotton weave is a good bet. That’s because at the microscopic level, the natural fibers in cotton tend to have more three-dimensional structure than synthetic fibers, which are smoother…That 3D structure can create more roadblocks that can stop an incoming particle
“Think multiple layers. Several studies have found that masks made of multiple layers are more effective at blocking small particles. A good option: a mask made of two layers of a thick-weave fabric with a built-in pocket where you can place a filter...The best bet for the material to slip in as a filter is polypropylene, which is derived from plastic.. “If you go to Walmart, you look for Oly-fun, which is the brand name of that fabric. It’s also called spunbond
“polypropylene is great as a physical filter but has another benefit: It holds an electrostatic charge. In other words, it uses the power of static electricity. Think of the static cling that can happen when you rub two pieces of fabric together, …That’s basically what’s happening with this fabric: That “cling” effect traps incoming — and outgoing — droplets. “That’s what you want — the cling is what’s important…And unlike other materials, polypropylene keeps its electrostatic charge in the humidity created when you breathe out
“Avoid masks with exhalation valves. Some cloth and disposable masks come with an exhalation valve at the front. The valve makes it easier to breathe out, but it also releases unfiltered air, so it doesn’t protect others if you’re contagious. And protecting others is the primary reason to wear a mask.
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