Coronaviruses are tiny averaging .12 μm in diameter. So what does that mean? The abbreviation μm stands for micron. A micron is one millionth of a meter or a thousandth of a millimeter (mm). A typical piece of copy paper is 0.1 mm or 100 microns. So it would take about 1200 COVID 19 viruses stacked up to equal the thickness of a single piece of basic copy paper.
While people refer to a virus as a bug, it does not have legs to move as an insect does. Instead a virus is thought to travel by droplets which are about 5 microns in size. Therefore about 240 droplets are equal to the thickness one piece of paper.
When making a mask, you need to think about what materials a going to best at filtering out tiny particles. Plain cotton fabric like from a bed sheet is made from weaving fibers in straight lines.

As this photo illustrates there are gaps between the fibers. If the fibers were laid out in a random pattern the gaps are lessened. To accomplish this fibers are bonded rather than woven.
N-95 masks are made from bonded polypropylene fabric. The number denotes the percentage of particles blocked. Hence the N-95 mask would filter out 95% of particles.
Another greater feature of this bonded polypropylene fabric is that it is water resistant. This is easily demonstrated by squirting water from a plant mister bottle onto polypropylene fabric. The water visually beads up on the fabric instead of being soaked up by the fabric. Yet the fabric is easy to breathe through.
Where can you find bonded polypropylene fabric? Hospitals routinely place surgical instruments into plastic trays and the warp the trays in two layers of polypropylene fabric (aka surgical wrap). This package then goes through a sterilization process and then sits on a shelf in a clean room until it is ready to be used. Prior to surgery the package is unwrapped and the wrapping material is discarded. Thus there is an under utilized supply ready to use. An anesthesiologist in Florida has staff making masks from these surgical wraps to combat their supply shortage.
Another source for the material, albeit not surgical wrap quality, is reusable shopping bags like this one. Click on the image or click here to find out where to buy some of these bags.
We recommend two to three layers of bonded polypropylene fabric for my masks. Our research suggests a 99% effectiveness in blocking particles. A layer of flannel makes a greater interior fabric as it is soft against the face.
Another important thing to consider is fit. Noses can be a challenge to fit around. Using a pipe cleaner, aka chenille stem, or uncoiled paper clip attached between the mask layers makes a simple and effective adjustable nose bridge. We offer several designs for FREE. Just click on one of the buttons to go directly to the corresponding design page.
Since the virus may live for 3 or more days on soft surfaces, we recommend making a mask for each day of the week for each person. Sewn masks are machine washable yet repeated washing may reduce their integrity. Old fashioned fresh air and sunshine certainly won’t hurt either.
Wash hands before putting on any mask. Once adjusted, try to keep your hands off from the mask. Wash your hands again after taking off a mask and after touching a mask you are wearing.
Keep in mind the virus needs to be viable in order to infect you. Just because you touched something contaminated does not mean you will automatically be sick. The best ways to protect yourself are hand washing, keep hands away from your nose and mouth, and physical distance of 6 or more feet between people. It has been scientifically determined that droplets travel about six feet.
Information provided is the opinion of MainelyDiY. Statements are not based on testing nor expertise. The material provided is to the best of our knowledge and is not to be construed as scientifically proven facts. Mask effectiveness depends on factors such as materials, fit, and proper usage. General public should use homemade masks in conjunction with social distancing not instead of physical distancing.
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