Note that if you do not approve of making and distributing masks, there is the whole rest of the internet for you to read and comment on. This post is about making and distributing masks.
Comments on this post about NOT making or distributing masks will be nuked from space. 😀
Many hospitals are reporting shortages of the N95 grade masks which are the standard for use with patients with Coronavirus, also known as Covid-19. Some hospitals are so short of supplies that staffers have been told to use a single paper mask per 12 hour shift. Obviously the best solution would be ample supplies of rated masks from an inspected manufacturer, but we don’t currently live in a world where that’s an option. We must look for alternatives.
An Anonymous volunteer in the medical field has created these instructions for masks which function similarly to the rated masks, and have removable filters, making them much more effective and practical than plain cotton masks. These can be used by medical staffers and also by non-medical people who simply wish to protect themselves from airborne viruses more effectively. It’s comfortable to wear, affordable to make, and machine washable.
We encourage anyone shut in, bored, and possessed of a sewing machine to create and distribute these masks. If your local hospital doesn’t need them (and ours does not) they can be sanitized after manufacture and distributed around your neighborhood as simply as hanging them on the bare branches of a tree, or putting them on doorknobs. Ask your local grocery store (an essential service and nexus) if you can pin them to its announcement board or pile by the till for the taking.
And now, the instructions, from an Anon:
I’ve studied mask designs from all over the internet, taken ideas from several wonderful people and put together what I think is the closest we can come to an N95 in terms of protection. All materials are easy acquire, so anyone with some sewing skill can make them.
I’ve chosen a tie-on design because I believe it will fit more snugly on a wider range of faces. For the mask and ties I’m going with 100% cotton for comfort and availability. The filter material will be harvested from a special type of furnace filter.
After much filter research, I’ve found one that blocks particles as small as .3 microns, which is the particle capture size provided by an N95. (Yes!) It is superior to HEPA. Here’s the filter I’m recommending.
I purchased a 20 x 30 for around $20. After disassembling it, I got a single piece of filter material about 29” x 93” (almost 8’ long!) The air flow through this material is excellent, yet it has very effective filtration and is widely available.
I’ve put this filter material through the autoclave (273F on a 45 minute cycle). It holds up wonderfully, so in theory the filter can be reused many times. Note air flow direction when disassembling filter and load into mask w airflow direction from outer room into mouth.
There’s another high-efficiency Filtrete filter out there w a red label. It’s not as effective as the purple one pictured above but could also work in a pinch.
For the outer cotton mask/pouch portion, which will be two layers, it was difficult to find a fabric which was very breathable yet durable and comfortable. I tried muslin , microfiber and cotton sheets, as well as cotton/poly broadcloth. I settled on flour sack towels.
They’re cheap, durable and provide great air flow, as well as being soft and comfortable. They can be found online and in big box stores in housewares. Here are a few examples of packaging:
You can use any fabric you like, within reason. Just make sure that it’s easy to breathe through 2 layers of it. The fabric is only there to provide a housing for the filter material, which is the critical protective element.
For the ties, I’ve found the ideal material is 1” COTTON twill tape. However, unless you buy an industrial roll, the tape usually comes in shorter lengths that make it inefficient and expensive for mass production. have an enormous stash of quilter’s cotton fabrics so I’ve decided to use that. It will entail more work than the 1” twill tape would but I don’t have to buy anything this way. I’ll give instructions for both materials. Here’s a closeup of cotton twill tape:
For the wire across the bridge of the nose, I’m using pipe cleaners. They come in two types – one with soft bristles and one w hard, scrubbing bristles. Obviously we want the soft ones. (This is another brilliant idea I stole from someone else.)
TUTORIAL SECTION: Wash and dry cotton mask and tie materials on hot, to shrink them prior to cutting, and so they don’t shrink later when the user washes them for reuse. Iron everything on high heat after laundering. Flour sack is naturally wrinkly. Just press dryer wrinkles out.
Cut the flour sack cloth into pieces 8” x 18”. The 8” edges will be the top and bottom, the 18” edges will be the sides. Fold the top and bottom edges over 1/4” and press. Fold again and stitch down.
Lay the piece flat with folded/stitched edges up. Fold the bottom edge up 5” and press. Fold the top edge down, so it overlaps by 1/2” – 3/4”. The goal is to have the piece measure 8” top to bottom. Stitch sides 1/4” from the edge.
Iron 2 pleats above the pouch opening and 2 below the pouch opening as shown, w each pleat having about a 1/2” fold. Press the peaks of the pleats toward the center. Spray starch may be helpful.
Tie straps: cut quilt cotton in 2”x36” lengths, two for each mask. If using twill, cut to 36”. Also cut an 8” length of whichever you’re using. Fold cotton strips in half. Press. Open and fold edges in to meet in middle and press again. If using twill, fold in half and press.
Place the folded 8” length along top of mask and center the pipe cleaner along the crease. Fold fabric over pipe cleaner and stitch down.
Center the straps over the pleated edges of mask, equal lengths off either end. Sandwich mask inside the two faces of the strap and stitch strap to mask. I start just above mask, sew to one end of strap, then flip and sew to other end of strap. Repeat for other side.
Place filter material beneath a press cloth and press out the pleats. Cut into 7”x 7” pieces, marking the side that will go toward the user’s face. Insert into mask, tucking into corners well. The mask is now ready for use! (Pouch opening goes toward face).