Facemask wires,filters and materials

You can help support this project, without money.

Updated 4:15 April 10

Complete list of open source and DIY plans for masks, 3D printing and ventilators and more is here.

I am working on many blog posts like this at once, and the following is not yet as organized as it will be. Most of the following are from the Open Source COV19 Facebook page.

NOTE
Materials used to manufacture HEPA vacuum cleaner bags contain glass microfibers which are very harmful to lungs and should NOT be used.

If you would like to include filters with your masks, some safe options are non-woven products like non-fusible interfacing or charcoal re-useable washable filters (Amazon). On the other hand, testing has proven that the simple insertion of folded tissues or paper towels into the masks greatly improve its effectiveness without inhibiting the breath-ability of the mask.

......

Paper tissue is dangerous to use. The filter layer needs to be non-wowen of polypropylen.
“Hydrophilic materials such as wipes, tissues, paper towels, or coffee filters are not ideal for the middle layer of the mask because the droplets in contact with these materials will spread out, penetrate through, and contaminate the wearer’s mouth and nose. A drop of water on the material can show if a material is hydrophobic or hydrophilic: it is hydrophobic if the drop beads up, hydrophilic if it spreads out.”
https://utrf.tennessee.edu/using-nonwoven-materials-in-diy-face-masks/?fbclid=IwAR2R_GkcrX8_5jOBnmEk4KUZKRQDTo77nuuN-zPgyIO-Mpi0gy-bhkHfMTk

.........

These are comments and links about materials. I am constantly organizing and editing all of these, and the organization is improving, but slowly.

The following are broken down into three groups:

Wires

Fabrics you likely have at home

Materials found in hospitals

Wires

Consider if the mask will be washed! The following materials will not rust.

Circular coil of aluminum craft wire (also called armature wire) in 2 - 2.5mm
Steel zip ties 5mm wide (both on Amazon)
Craft wire because is more malleable and bendy. The steel zip ties are less malleable and hold their shape more, but still work. You need metal shears or wire cutters (that you don't mind abusing) to cut them and might want to sand the edges a bit with low grit sandpaper or a metal file.
  • Metal shears are recommended for cutting steel ties; better than damaging your wire cutters. Inexpensive too.
  • 14g 4 wire flat speaker ribbon.
  • Galvanized fence wire is easier to cut and work with than the steel zip ties and comes in large spools at any Home Depot.
  • https://www.amazon.com/Pandahall-Silver.../dp/B07JKCKBRN

Every day fabrics that you likely have at home:

You can use fine men’s shirting or high thread count sheets for fabric. You can use a third layer of cotton fabric in center if you can’t access HEPA quality fabric. Also you could use a non woven interfacing for that interior layer. The idea is that the three layers of woven fabric are offset from one another causing air when it migrates in or droplets when they migrate out to not have a straight path. If you use non woven interfacing even better because it is a complex matrix. The entering particulates collide so to speak with the fibers and are captured. Also you can consider a synthetic fabric for the middle layer since many polyesters and nylon are charged and can better capture charged cells. Instead of the pony holders I’ve used fold over elastic about 28 inches long to bind each short side of the mask. This leaves stretchy tails for tying (makes it easier to fit) as you just zig zag across folded over elastic from one end to the other. Many have also used garbage bag wires and plastic floral stems for the nose piece, you can sandwich it in duct tape so it stays waterproof. I suggest inserting it into a 4” casing made with fold over elastic sewn to the lining side of the mask. This way you can reinsert new wire as needed. Lastly after you turn it consider top stitching around to increase durability. Good work guys!

Filter materials/Materials found in hospitals

 https://m.ufhealth.org/news/2020/uf-health-anesthesiology-team-devises-respirator-mask-made-existing-hospital-materials

https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus

In Gainsville FL, nurses have been using the surgical fabric that is used under tools in surgery. It is 99% non permeable and we have a group that is promoting use of that fabric as opposed to cotton for homemade masks. For sewing groups in our MN area we are supplying the fabric to keep our front line workers safer. Anyone can buy the fabric, resources are on the site. maskarmy4heroes.weebly.com

Commercially available medical fabrics and filters

..........

It was shared with me that the product called Halyard H600 2 ply spun polypropylene is being made into masks with the support of the University of Florida. Dr. Bruce Spears a professor for anesthesiology the U of F College of Medicine recommended the use of this product based on the manufacturer's recommendations. He stated that the masks are 4% more effective than the N95. This information is on the University of Florida website. I am a University of Iowa RN and have a BSN. I have been sewing many years also.

A study into the effectiveness of home made face masks done by I think it was Cambridge University in the UK showed that any more than 2 layers of fabric made negligible effects on the effectiveness of the mask. On particles the size of SARS2 nCoV, no matter the number of layers, woven cotton rarely blocked more than about 50-60% of the air born particles. This style of mask only really shows it's effectiveness when everyone wears them and uses them as a method of slowing the spread rather than a method of protecting the wearer from infection. But as the aforementioned study left in it's foot notes "A mask is better than no mask".

Thank you for posting this. On a related note, existing face masks can be treated with polyethelyneamine and or catechin, an African plant, to create an effective viral blocking mask; Here are some selected citations; "Studies published by Tiliket et al. and Catel-Ferreira et al. in 2015 demonstrated a cellulose based material for airborne virus filtration in which a low-cost non-woven cellulose material (Kimwipes) were chemically modified by coating them with polyethylenimine (PEI) or grafting in an antiviral agent; catechin." "The filtration efficiency of the modified filter media was first tested on aerosolized T4D viruses (Enterobacteria phage T4, Doermann’s strain T4D). Then the treated filter was inserted inside a commercial medical mask in place of its cellulose layer and the reconstructed mask was challenged with TD4 aerosols to evaluate its virus removal efficiency." "Both treatments significantly improved the virus capture factor (ratio of upstream to downstream PFU contents) of KW cellulose wipes and of reconstructed commercial masks when compared to original masks and to masks reconstructed with untreated wipes." Tiliket, Ghania & Ladam, Guy & Nguyen, Trong & Lebrun, Laurent. (2016) published "Polyethylenimine surface layer for enhanced virus immobilization on cellulose." Search for that article online. Polyethylenimine (PEI) is a polycation, which is readily adsorbed by the cellulose matrix from a 0.1% w/v solution in NaCl 0.2 M (ca. 100 ng cm−2). Further PEI adsorption steps at higher PEI concentrations induce a linear growth of the PEI films, suggesting that free adsorption sites still exist after the initial adsorption. The adsorbed PEI chains are resistant to variations of the ionic strength up to NaCl 1 M. "Promisingly, the adsorption of T4D bacteriophages are 15-fold more efficient onto the PEI-treated fabric, compared to the native regenerated cellulose films, as measured by QCM-D. This confirms the strong affinity between the negatively charged viruses and PEI, even at low PEI concentration, probably governed by strong electrostatic attractive interactions. This result explains the remarkable improvement of the affinity of medical masks for virus droplets when one of their cellulose layers was changed by two-PEI-functionalized cellulose-based filters." Polyethylenimine is commercially available. This should be of interest to DIY mask makers.1

Rachel Lei From an admin of a SoCal #StitchedTogether group

IMPORTANT (FILTERS): We have had many posts suggesting the creative use of pleated filter material extracted from a 3M Filtrete Air Filter. For safety’s sake, we contacted 3M today and talked with them about this material being incorporated into a face mask. They strongly stated that the air filter material should NOT be used for this purpose. This material is specifically manufactured by their construction division for use in a furnace, and it should never be incorporated into personal protective wear. Since 3M also makes the N95 masks, they are experts on what materials are safe and healthy for face masks. Additionally, their Material Safety Data Sheets for Filtrete warns: "Use or processing of the product not in accordance with the product's recommendations or not under ordinary conditions may affect the performance of the product and may present potential health and safety hazards."

Additionally, materials used to manufacture HEPA vacuum cleaner bags contain glass microfibers which are very harmful to lungs and should NOT be used.

If you would like to include filters with your masks, some safe options are non-woven products like non-fusible interfacing or charcoal re-useable washable filters (Amazon). On the other hand, testing has proven that the simple insertion of folded tissues or paper towels into the masks greatly improve its effectiveness without inhibiting the breath-ability of the mask.

We know there is a wide amount of conflicting information on the internet. However, in light of the health hazards our front-line people are already facing, we believe it is in everyone's best interests to be safe and avoid using these materials for our masks. Thank you very much for your understanding.

......

HI.. from me, Stephen Black

I was working on AR learning game ideas before this situation, but have released this early because schools are closed. It is free. Oakbub and Bubiko's AR Alphabet.

5 thoughts on “Facemask wires,filters and materials”

  1. Pingback: COV19 PPE: Open source/DIY plans + materials - blackstepsblacksteps

  2. are you the source of this info? parts of it are found on various fb posts and I’m trying to track down the source. Thanks!

    1. Robin, most of those are condensed from FB, the Open Source Covid 19 Medical Supplies group/page. I did not include names because of privacy and time issues.If you are looking for a specific piece of info, let me know. The FB group is great but the comments are often repeated or not clearly written. They are not organized efficiently, due to the nature of FB.

  3. It’s a great initiative trying to gather recommendations. However, they need to be safe. Paper tissue is dangerous to use. The filter layer needs to be non-wowen of polypropylen.
    “Hydrophilic materials such as wipes, tissues, paper towels, or coffee filters are not ideal for the middle layer of the mask because the droplets in contact with these materials will spread out, penetrate through, and contaminate the wearer’s mouth and nose. A drop of water on the material can show if a material is hydrophobic or hydrophilic: it is hydrophobic if the drop beads up, hydrophilic if it spreads out.”
    https://utrf.tennessee.edu/using-nonwoven-materials-in-diy-face-masks/?fbclid=IwAR2R_GkcrX8_5jOBnmEk4KUZKRQDTo77nuuN-zPgyIO-Mpi0gy-bhkHfMTk

  4. Mette, Thank you…I will move your comment to the top. I agree with you, but as you likely know, for some it is a case of using whatever is available, aware that it is not optimal. Thanks again.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.