https://www.popsci.com/story/diy/make-diy-face-masks/
Polypropylene bags can do more than carry groceries—they can also be turned into face masks. (Alden Wicker/)
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As COVID-19 spreads across the United States, hospitals are struggling to keep fully functional while running through their limited supplies of face masks, gowns, and other protective equipment.
The Phoebe Putney hospital in Georgia went through six months of supplies in less than a week, Stanford Hospital in California has asked sustainable t-shirt startup For Days to make cotton terry cloth N95 mask covers, and even high-end fashion designers like Christian Siriano have begun making medical-grade masks and gowns.
“No one before would have thought of fashion designers or anybody helping with DIY masks,” says Katie Kozel, a medical supply chain consultant in Colorado. “But no one before would have thought of trying to use rain ponchos as isolation gowns either, which we’re seeing happen now.”
Tutorials for DIY masks have proliferated across social media and the internet as news of the dire conditions in hospitals across the country hit the news, and people want to pitch in. But the value of such a mask may not lie so much in helping medical professionals, but in helping to protect yourself and the people around you.
The difference between N95 and surgical masks
N95 respirators are stiff masks with a filter that blocks 95 percent of particles larger than 0.3 microns, and are fit-tested to each healthcare worker to ensure they create a sealed barrier. Like most personal protective equipment (PPE), N95 masks are meant to be discarded after each use. But as a result of the shortage, the CDC has recommended healthcare workers store their used N95 masks in paper bags between uses, which raises the risk of disease transmission between healthcare workers and patients.
In contrast, surgical masks are loose-fitting coverings made of pleated melt-blown fabric: a fine mesh of synthetic polymer fibers that allows the wearer to breathe while blocking tiny particles that could carry the virus. However, they don’t fit as tightly as N95 respirators, so they don’t provide the same protection against airborne coronavirus particles (which may persist in the air for up to three hours).
Surgical masks aren’t meant to shield the wearer from infection, but to protect others by corralling any infectious droplets that may come out of your mouth or nose—whether you’re symptomatic or not. That’s why authorities have insisted only people presenting symptoms or suspected of having COVID-19 should wear them.
However, healthcare professionals now have no choice but to wear surgical masks around COVID-19-infected patients, donning the safer, scarcer N95 respirators only when performing risky procedures like intubation. And even surgical masks are running low.
Cloth masks as an alternative to medical masks
Cloth masks aren’t impenetrable, but some research suggests they may be better than nothing. (Pavel Anoshin/Unsplash/)
Researchers at the University of New South Wales who studied the use of reusable cloth masks several years ago found that doctors who wore them had a significantly higher chance of respiratory infection. Almost 97 percent of particles got through the cloth masks used in the study, compared with the 44 percent that penetrated synthetic medical masks. The cloth’s ability to retain moisture, plus the fact that the masks were reused, might have also contributed to their inefficiency.
No wonder that the World Health Organization says cloth masks are “not recommended under any circumstances” in healthcare settings during the COVID-19 outbreak.
As the pandemic advances, however, experts are starting to question whether cloth masks could help the general public. That’s because it’s still unclear how wearing a cloth mask compares to wearing no mask. A 2006 study by researchers from the University of Pittsburgh pointed out there’s no easy way to prove the effectiveness of homemade masks. On the other hand, researchers in a 2013 study by Public Health England concluded that while "a homemade mask should only be considered as a last resort,” it might be better than nothing at all.
How to make a face mask
Let’s make this clear: masks, no matter how effective, are not guaranteed to protect you from COVID-19.
“A mask is only ever as good as the wearer, and isn’t a replacement for social distancing and good hand hygiene,” says Anna Davies, one of the researchers in the Public Health England study.
In a perfect world, everyone would have their own masks to wear in public to help prevent the virus from quietly spreading, and the CDC is reportedly considering recommending that everyone wear masks in public, not just those with symptoms.
Unfortunately, masks are a bit hard to come by right now, and buying masks reduces the supply for healthcare workers who need them. Even if the CDC doesn’t make a new recommendation, anyone taking care of a sick loved one should probably have at least two, so they can sterilize one while wearing the other.
Our tutorial is a simple project for people who don’t have a sewing machine, adapted from MakerMask by Helpful Engineering, a global open-source COVID-19 project. While many projects call for cotton, Davies says there’s no indication it is better or worse than other fabrics—it’s just comfortable and something people tend to have on hand. Because of researchers’ hypotheses about cotton masks’ hydrophilic (water-loving) qualities contributing to higher rates of respiratory infection, we’ve stayed with MakerMask’s suggestion to use a hydrophobic synthetic material similar (but not identical) to the material used in surgical masks. And many people have it right in their own home.
Stats
Time: 90 minutes if sewn by hand
Estimated materials cost: less than $5
Difficulty: medium
Tools
- Needle and thread
- Scissors
- Ruler
- <a href="https://amzn.to/2JutH9A" target=_blank>Clothing iron</a>
- Sewing or safety pins
- Permanent marker
- (Optional) Seam ripper
Materials
- 1 medium non-woven polypropylene reusable grocery bag
- 2 <a href="https://amzn.to/2JAgnR0" target=_blank>pipe cleaners</a> (or <a href="https://amzn.to/2UZgtap" target=_blank>plastic-coated twist ties</a>)
- (Optional) 60 inches of <a href="https://amzn.to/3aO0TVP" target=_blank>ribbon, between ½ and 1 inch wide</a>
Instructions
You most likely have everything you need to make one of this at home. (Alden Wicker/)
1. Wash the reusable grocery bag.
- <b>Caution:</b> We specifically recommend a reusable grocery bag <a href="https://ift.tt/342AkJT" target=_blank>made of non-woven polypropylene</a> (NWPP for short), not a disposable plastic one. It may sound obvious, but you’ll need to be able to breathe through the mask. Stay away from insulated bags (these usually have some foil material on the inside) or waterproof bags lined with plastic, too.
- <b>Note:</b> If you can, choose the bag with the longest handles you can find. This project will be easier if you can use them as straps for the mask. If the handles aren’t long enough, we’ll explain how to make straps out of ribbon.
2. Cut the sides off the grocery bag so the material lays flat. Don’t cut off the handles.
3. Cut the material into two sheets. If your bag has a seam at the bottom, cut it like you did the side seams. You’ll get two clean sheets of NWPP, each with its own handle.
Your mask will have two layers of fabric. (Alden Wicker/)
4. Measure and cut one sheet. Using your ruler, measure the edge with the handle to find the center. Mark it with your permanent marker. Using that as a starting point, measure back toward the handles 4 ½ inches and mark again. From each mark, measure down 9 inches and draw parallel vertical cutting lines. Connect the lines at the bottom. You should have a 9-by-9-inch square with a finished (sewn) edge at the top with the handle.
- <b>Note:</b> If your handle is spaced too widely to fit inside the square you measured, the simplest solution is to skip over <b>Step 8</b> and use ribbon instead (<b>Step 9</b>).
5. Repeat Step 4 on the other sheet of material.
6. Fold over the edge opposite from each handle. Place one sheet with the wrong side (the bag’s former interior) up, and fold half an inch of material in from that edge. Iron the fold on low heat to set it. Then, sew it a quarter inch from the edge. Place the other sheet with the right side (the bag’s former exterior) up, and like the other sheet, fold it in a half-inch, iron it, and sew it a quarter-inch in from the edge.
- <b>Caution: </b>Polypropylene is a type of plastic. Using a high heat setting will melt it, ruining your project and, most likely, your iron. If there’s no “poly” setting, try the lowest one (usually silk) and increase it slightly if the fold doesn’t set.
Set each fold with an iron, but be aware of using it at the right temperature. (Alden Wicker/)
7. Place the sheets together. Your mask will have two layers of fabric. Place one of the sheets on your work surface with the handle facing to the left. Place the other one on top of it with the handle facing to the right. Pin in place.
- <b>Note:</b> We recommend that the printed side of the sheets face the same direction, so the back of the mask is a different color than the front. Davies says this will help ensure you don’t accidentally put the mask on the wrong way, with the contaminated side against your mouth and nose.
Pin the fabric sheets together. It’ll make sewing them together that much easier. (Alden Wicker/)
8. Make the head ties. Fold the handles in half and cut them at the center. Hold the mask centered over your face with the handles coming out of the sides, and make sure the handles are long enough to reach the back of your head with at least 4 inches to spare.
9. (Optional) Make straps out of ribbon. If the handles of your bag are not long enough to become straps, you’ll need to make your own. Cut the handles off your NWPP sheets or use a seam ripper to take them out. Hold the mask in the center of your face and use your measuring tape to figure out the length of each strap—they should each be long enough to go from the edge of your face to the back of your head and comfortably tie behind it. Cut the ribbons and pin them where the handles used to be. Check the fit by putting your mask on. If the length of the ribbons is right, double your thread and sew the pieces into place on the wrong side of the sheets.
10. Sew the sheets together. Double your thread and sew around all the edges.
11. Finish the bottom edge. Like you did in Step 6, make a half-inch fold at the bottom and iron it. Sew it closed a quarter-inch from the edge.
12. Make the adjustable noseband. Again, fold half an inch of the top edge over and iron it. Twist the pipe cleaners or twist ties together and cut them to the same width as the mask. Fold in their ends to blunt them. Tuck the metal ties inside the fold and pin the fold over them. Then, sew the fold below and on the sides of the ties to hold them in place.
Those twist ties you accumulate every time you buy a loaf of bread can make the perfect noseband. (Alden Wicker/)
12. Make three folds to pleat the mask for expansion. Pleats should be approximately 1 ½ inches wide on the outside, a half-inch wide on the inside, and be parallel to the nose band. If it helps, mark lines on your fabric, fold them, and then iron them in place. Stitch these in place by sewing both sides a quarter-inch in from the edge. This time, double back your stitch to make sure the pleat seam is strong.
Make three folds on your mask and set them with an iron. (Alden Wicker/)
13. Sterilize your mask. Before using it for the first time, submerge your mask in boiling water for 10 minutes. Repeat this step between uses.
It’s important to remember a face mask by itself is not enough. Make sure you also wear glasses or goggles to protect your eyes, and never touch the part that covers your mouth. When you’re done using it, sterilize it, let it dry completely (in the sun if you have access) to stave off any bacteria growth, and then store the mask in a clean, plastic, resealable container.
This DIY mask is not meant to be donated to a hospital, but kept for yourself, your family, and your community. In a time of mask shortages, it’s a “better than nothing” precaution if you need to move through a crowded or public space, or take care of someone who is sick. Please follow instructions from your local authorities and remember that social distancing, washing your hands thoroughly, and staying home are still the best ways to protect yourself and your family from COVID-19.
via Popular Science – New Technology, Science News, The Future Now https://www.popsci.com
April 2, 2020 at 08:20AM
