In the past few weeks (Jan/Feb 2020) several people have inquired about fabrics to make face masks. So we asked our quality team to provide some insight.
*Disclaimer: The article below is based solely on the opinion of the author. None of the statements below are based on any tests, experience or expertise on face masks. The objective of this article to provide some information on face masks and fabric suggestions to the best of our knowledge, it is not to be perceived as professional advice. No tests were performed to substantiate the recommendations. There is no guarantee that following them will prevent infection. The company holds no responsibility or liability about performance of the fabrics or masks made using them.
Searching for guidance on protective masks I came across this information on Face masks being regulated by the FDA as medical devices. This says “While a facemask may be effective in blocking splashes and large-particle droplets, a facemask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes or certain medical procedures. Facemasks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the facemask and your face.”
The FDA Guidance for Industry and FDA Staff on Surgical Masks is a complete guide on how to prepare a Pre-market Notification submission for selling surgical masks and other protective masks. I reviewed a few of the submissions and they were all for single use masks made using layers of polypropylene, held in place using ear loops or elastics or tie strings, to be disposed after each use.
I also looked at CDC’s guidance on respirators for non-occupational use. It says “Three key factors are required for a respirator to be effective: (1) the respirator has to be put on correctly and worn during the exposure; (2) the respirator must fit the user’s face snugly to minimize the number of particles that bypass the filter and get into the breathing zone through gaps between the user’s skin and the respirator seal; and (3) the respirator filter needs to be highly effective at capturing particles that pass through the filter."
Designing effective face masks for good protection from infection is not an easy task. These devices are regulated by the FDA and there are rigorous testing requirements to make sure they are safe and effective. When designing one some important things to keep in mind seem to be*:
- Adequate Size & Good Fit to cover the nose and mouth to allow for entry of air only through the mask. Knit fabrics have some stretch and can be used to make masks that fit the face snugly without being uncomfortable, many woven fabrics have no stretch (like the single use polypropylene ones see paragraph 1). A good, snug fit depends on the construction, to make sure there are no gaps at the edges that can allow entry/escape of particles. Patterns for face masks are available on the internet, but all may not be effective.
- Adequate Filtration to prevent transfer of particles while breathing, this can be accomplished by using multiple layers of closely knitted (or woven) fabrics. (This is not based on any testing, just based on the fact that surgical masks use three layers of polypropylene, and the N95 respirator construction that has 4 layers – outer hydrophobic, middle nonwoven for filtration, a support layer and an inner stay dry.)
- Breathability to allow for easy respiration. Layering breathable fabrics allows for good breathability along with good filtration. Surgical masks generally use three layers of thin polypropylene, while respirators have 4 layers of which one is a support layer.
- Protection from microbes might be possible by using antimicrobial fabrics that have a wide spectrum of activity, such as those treated with the Antimicrobial Silvadur. There are advocates for and against antimicrobial fabrics, this is a choice you have to make. Based on recent reports it is advisable to stay away from nanosilver treatments until they have been vetted for being safe.
- Comfort against the skin is important especially with the high humidity condition created by breathing through the mask and the risk of saturation. Using a stay dry, wicking fabric on the inside can move the moisture away from the face would make the mask comfortable to wear.
Holding the mask in place can be accomplished by using elastic ear loops or elastic bands that go around the head which seems to be a more secure method.
A good washing/sanitizing routine is important for reusing them.
1. Elastics – The elastics below are made in USA and known to be durable. Elastics for Face Masks Fabric Finder
- Mobilon Elastics - latex free
- Braided Elastics
- Knitted Elastics
- Fold Over Elastics (FOE) - these are also latex free.
A. Fabric suggestions for making Face Fitted, Cone Shaped with Nose Bridge Type Mask – (not pleated)
Note: Since the layers are relatively thick a binding or FOE can be used to bind the edges.
2A. Inner layer – Stay Dry fabric for wicking away moisture/humidity. If polyester does not suit you, a smooth cotton or bamboo antimicrobial like a jersey or interlock may be used. Inner Layer for Face Masks Fabric Finder
- ProCool Wicking Fabrics
- Dri-Qwick Fabrics offers the best wicking properties
- ProCool Jersey, ProCool Pique & ProCool Interlock offer the best lightweight wicking properties.
- Cotton Fabrics
- Bamboo Fabrics
3A. Filtration layers of fabrics could be layers of Zorb fabrics, or other cotton, bamboo fabrics. A minimum of three layers for filtration, (except for 3D Zorb which is itself a 3 layered fabric) but add more depending on what fabrics are being used. More layers mean better filtration, but it also has to be breathable and comfortable. Filtration Layer for Face Masks Fabric Finder
The best options for good filtration seem to be Zorb fabrics. Zorb Original is a Nonwoven and the fibers filled in the 3D Zorb are more tangled and would offer good filtration. Please note that it is NOT Recommended to use Zorb Original by itself, it can be sandwiched between 2 other fabric layers.
Then 3D Zorb Organic Cotton Dimple & 3D Zorb Stay Dry Dimple have a slightly different construction, the fibers are less tangled and may feel slightly rough, but it will also work well esp. if you are keen on using a natural fiber (cotton version) or for better performance (stay dry version)
Additional layers can be added as required from the other fabrics, the heavier fabrics will have better filtration (less breathability), but if you are using any of the 3D Zorbs, then light fabrics will work better and feel more comfortable.
Substitutes that will work are fleece fabrics – the fleece structure provides a tangled surface to trap stuff. The heavier fabrics provide more filtration, lighter provide more breathability. I wish I could provide a perfect recommendation but without having any test results this is just based on fabric construction
- Zorb Original
- Zorb 3D Dimples
- Zorb 3D Diamonds
- Zorb 3D Heavy Dimples
- ProECO Bamboo Fleece
- ProECO Cotton Fleece
- ProTEC Micro Fleece
4A. Outermost Layer - A good option is the new ProCool 1-way Wicking Fabric in which one side is hydrophobic. It allows wicking only in one direction if positioned correctly so that inner moisture can wick out and not the other way. (Based on the N95 respirators in which the outermost layer is hydrophobic, i.e. repels water.)
Other ProCool fabrics can be used as they are quick to dry. Use the plain side facing out and the mesh pattern side facing in for a better effect, but either way will work. Outermost Layer for Face Masks Fabric Finder
B. Fabric Suggestions for making Pleated Type Face Masks
2B. Inner layer - Same as above.
4B. Filtration layer - Same as above or other woven/knitted cotton/linen/bamboo
Some people have asked about using waterproof PUL as an outer layer. According to me PUL will not provide sufficient breathability for a mask.
It is an excellent barrier, waterproof and will not allow penetration of particles at all, so can be used as a protective barrier for short term use, esp. at such times when we are resorting to using bandanas for protection.
More and more people are turning towards antimicrobial fabrics for better protection from the virus. Antimicrobial options are available for many of the suggested fabrics, should you want to use them. Good construction of the masks is very important so that they fit well. Make sure you can breathe comfortably through the layers.
*Disclaimer: The above article and recommendations are based solely on the author’s knowledge of our fabrics, understanding of the guidance documents and the articles referenced. Links to all references have been provided above so you can read and understand them yourself and make your decision. We do not make any claims to the effectiveness of the product. No tests were performed to substantiate the recommendations.
Please note other fabrics may be used in making such protective face masks for personal use. Other fabrics have not been listed as I have no knowledge as to their construction, safety and how they work. Use of antimicrobial fabrics is a personal preference.
Face masks and respirators for medical use are regulated by the FDA in USA. Please see this link for some information on FDA Regulation of Surgical Masks and Respirators