These masks are not made to kill viruses. They are filters that act like a sieve that blocks certain particle sizes from passing through.
These masks are also combined with protocols to put on and remove them safely to avoid risk of contamination through your hands.
This FAQ from CDC is a great example of how these masks perform.
Do surgical masks provide protection against SARS?
Surgical masks are not designed for use as particulate respirators and do not provide as much protection as an N-95 respirator. Most surgical masks do not effectively filter small particles from air and do not prevent leakage around the edge of the mask when the user inhales. (3)
They are meant to reduce the risk that you contaminate the others, by reducing the velocity of your saliva particles.
When the mask becomes damp, it loses its protective capacity, and may create a capillarity effect that makes particles transport through materials alongside humidity.
It should always be washed after every use, and the soonest possible after removal to avoid other contamination through contact.
“Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance.” CDC, Coronavirus Disease 2019 (COVID-19)
Neoprene (sometimes referred to scuba knit), laminated materials, membranes, coatings.
Be careful with calendered materials.
As masks are to be worn on your nose and mouth, it is needless to say that you need to be able to breath though. As simple as this may seem, the way that some materials are presented may confuse a misinformed buyer. The above mentioned materials contain a “plastic” layer that blocks air flows.
In a nutshell, it is pretty much like wearing a plastic bag over your head.
PUL stands for polyurethane laminated. This means that the fabric is laminated with a polyurethane membrane which blocks air to go through.
There are two types of polyurethane membranes on the market : non-breathable and breathable. The wording is confusing as in reality both do not let airflow go through. “Breathability” in this case stands for the capacity to transmit vapor through the membrane, not air.
We did not encounter conclusive studies on whether synthetic fibers (such as polyester, nylon, polypropylene) or cellulosic fibers (such as cotton, hemp, linen, lyocell, viscose) are retaining for longer amount of time than the others the viruses on their surface.
Although, no matter the time these materials retain viruses, the importance is to wash them at the earliest convenient moment, and always after use.
A study suggests that protein fibers (such as wool, and silk) tend to retain the virus for a longer period of time, in comparison to cellulosic and synthetic fibers.
More layers, means less velocity of the particles, but it also means less airflow.
We would recommend two layers at least, while testing prior to wearing for a longer period of time the breathing comfort of your layer system.
Antimicrobials should not be considered effective on viruses unless proven otherwise, and on a specific strain of virus with supporting documents.
Antimicrobial /antibacterial should be considered an added value, but you should be careful when marketing it to your clients, so that they do not confuse it with an antiviral property.
We also recommended being careful to the contact with the skin & airways. Some treatments may contain less recommended components, or even be harmful.
Water repellent finishes are added to the surface of materials to repel water and liquids from its surface, but it is not made to avoid water penetration. Unlike coatings and laminated membranes, water repellents do not affect the breathability of a material, it reduces its absorbency of liquids.
Therefore, water repellent finishes are an added value, and should be carefully marketed to avoid misdirecting the clients. It doesn’t mean that the viruses will not remain on the surface of the materials, it only means that if a liquid, such a droplet would land on the outer material it will facilitate its repellency.
We also recommend using a second layer between your skin and the water-repellent material.
Filters are nonwoven materials which are aleatory placed fibers or filaments (no yarns) maintained together by either : glue, mechanically induced tangles and or heat application.
Filters and nonwovens are mainly developed to control the particles and airflow while materials like wovens and knits are developed for resistance to tearing, abrasion, extensibility, etc. Due to their construction, the integrity of the structure and filtration of nonwovens is more sensitive to cleaning in washing machines. The agitation, water, soap, and heat, can drastically affect the material by displacing the fibers creating more space for particles to go through, therefore reducing its effectiveness.
Wovens are warp and weft yarns overlapping each other in a regular pattern.
Knits are single orientation yarns (warp or weft) interlacing in loops.
|© 2020 Tengiva, a division of CACITH inc.|
"Behind every great product, there is a sample." － Annie, founder
|© 2020 Tengiva, a division of CACITH inc.|