Holistic and Timely Use of Filtration Resources Needed to Fight COVID

Face Masks will be the Focus on Wednesday at the WFI Conference

Researchers at King Abdullah University Develop Membrane for Face Masks

TTG has Efficient Membrane Media for Masks

ePTFE Membranes - Application in High-End Face Masks

DHA Uses Same Media for Masks and Gas Turbine Inlet Filters

TEFM Provides ePFTE Membranes for Masks

Membranes for Mask Supplied by Cobetter

BYU Develops Nanofiber Mask

Nanofiber Media Reduces Face Mask Resistance

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Holistic and Timely Use of Filtration Resources Needed to Fight COVID

The filtration industry can save hundreds of thousands of lives in the next year regardless of how fast vaccines can be produced and delivered. More efficient masks and air filters are needed. Alternatives are not nearly as effective because

·         Sanitation is proving to be a minor solution because the virus is airborne.

·         Social distancing is as effective in avoiding virus as it is avoiding perfume or cigarette smoke.

·         Partitions cause turbulence and can cause viruses to remain in suspension but do not prevent the small particles from easily flowing around any structure.

·         Increasing the amount of outside air flowing through a room is hugely expensive as opposed to filtration.

The challenge is to make adequate numbers of efficient masks and filters available now but avoid the cost of mothballing newly built facilities when the vaccines become effective.

There is a holistic approach which will accomplish this goal. All air filters are essentially just filter media with a support structure. Membranes can be used in masks and in gas turbine intake filters. There are very specialized facilities to make the media but a variety of sources can be utilized to make the structures,. Many of these sources can add second shifts and produce filter housings or masks and then switch to some other products.

The Mcilvaine forecast for the 2022 filter market done last year is now outdated but does show the use of membranes, non wovens and other media in various filtration applications.  By using a variety of media types in masks and air filters there will be enough media for the short term and no need to build facilities which would only be used temporarily. The fact that there are a number of different  types of vaccines being produced is comparable to using a number of different media types.

There is a fast track program to expand world vaccine production by orders of magnitude over the period of a year or two and then scale back. This is much more of a challenge than scaling up to produce the necessary masks.

In terms of filters there are small air purifiers, larger laminar flow systems, fan filter units, and  upgraded HVAC systems.

All of these products will save lives.  However, none will have the cost/benefit ratio of masks.  The holistic program should therefore prioritize  mask production.

Wildfire health impairment is steadily increasing. There is growing evidence that trace contaminants such as lead in the air are more prevalent than previously known. So even in a city such as St Louis it will be wise to wear a mask when the wind is blowing from the lead smelter. For many cities around the world air pollution is the cause of hundreds of thousands of deaths. Allergies impact millions. Many people have sensitive lungs.  All  of these factors provide long term demand for masks.

There will be a mix of disposable and reusable masks. But as shown in the daily CATER Mask Decisions the CATER Mask has the comfort, attractiveness, tight fit, efficiency and reusability which is needed.

Since a CATER mask could be used for 30 days or even longer it will require much less media.

Disposable masks will use much more media and will be less effective. If the mask costs $2 and is used for one day the monthly cost would be $60.  A $50 dollar CATER mask will have an 80 percent net efficiency or $0.63/ unit of efficiency vs disposable masks at 20 percent net efficiency or $3.00/unit of efficiency.

The disposable cost per unit of efficiency is 14 times that of a reusable mask with a 90 day life.

The cost per unit of efficiency of masks and filters is a function of the viral load as well as the filtration cost and efficiency.

An emitter of the virus is filtering out 100% of the load.  So the cost is only $0.63/ unit of virus avoided. He will also be a recipient. So even though the cost as a recipient is relatively high the net combination is less than the 0.63/unit efficiency. 

Upgrading an HVAC system is likely to involve less than 1% of the viral load generated by the individuals in the building. The problem is that recipients are likely to be located so that they are exposed prior to the ultimate removal in the HVAC system.  Even in an optimal setting with very good downward laminar flow air and exposure to 10% of the virus before it reaches the recipient the net unit efficiency cost is still higher than the mask.

Air purifiers in the rooms of people in households with coronavirus will come close to the unit efficiency cost of the mask but air purifiers in locations where there is no known virus are less cost effective.

A combination of masks and vaccinations can create herd immunity quickly. It will be a combination of CATER, surgical and medium efficiency cloth masks. It will not include inefficient cloth masks.

Because CATER masks are tight fitting, efficient, comfortable, and attractive they will be 93% effective where utilized. It was determined that only one mask would be needed per month and possibly only one per quarter due to reusability. This will be the most cost-effective option. 

The following table was presented last week in our Alert. Since that time there has been a change in the likely number of people vaccinated. On the other hand we learn that even with a 94% effectiveness most people will still want protection in case they are part of the 6%. Other vaccines with 60% effectiveness will result in no herd immunity even with 70% of the people vaccinated.

Therefore we still calculate that it would be desirable to spend $98 billion per month from now until June and then $60 billion per month in the subsequent quarter. This could drop to under $10 billion per month  by February of 2022.

 

There is a very large market potential for non COVID applications.

 

The potential for the COVID applications is much higher than other applications through 2021 but by 2022 it will be smaller than the other combined markets. So if CATER mask suppliers can capture a big share of the non COVID market there is not much of a peak and valley.

 

 

It is unlikely that CATER mask suppliers can scale up to $118 billion in revenues in 2021, but if they could capture 70% of the market there would be no downturn in 2022 and only a slight reduction in 2023.

The present revenues for masks which truly fit the CATER criteria are only around $200 million.  This means the 2021 market potential is 600 times larger than the present market. The long term market is 300 times the present market.

The challenge is to persuade people in highly polluted cities, in an area where there is wildfire smoke, working in meat processing plants, or just riding the subway that if they are going to wear a mask it should be a CATER mask.

It would normally be impossible to increase revenues for a type of product by 50 fold let alone 600 fold.  But the pandemic creates a huge opportunity for mask suppliers.  If they do not seize it many thousands of people will die. So it is not only the profit motive which should drive the mask suppliers.

CATER Mask Decisions will be providing the evidence which will show why CATER masks are the best choice for the wide range of applications. Mask suppliers can take advantage of this free service to educate their prospects.

Face Masks will be the Focus on Wednesday at the WFI Conference

The Conference's theme is "IAQ Health and Safety Solutions Associated with COVID-19", December 15-16, 2020, 8:00 am -12:00 pm EST. It will address the critical roles of facemasks and air filtration during the current pandemic for public health and safety. The virtual conference will feature the following four sessions:

1. Emerging Challenges and Responses

2. IAQ and the Built Environment

3. Facemask Technologies and Latest Developments

4. Facemask/Air Filter Test Methods and Standards

 

Face masks will be discussed on Wednesday.  One of the speakers will be Wendover Brown, Her background is provided at  https://www.wfinstitute.com/post/fashion-in-efficient-consumer-masks

You can sign up for one or both days at REGISTER NOW!

Researchers at King Abdullah University Develop Membrane for Face Masks

N95 masks filter about 85% of particles smaller than 300 nm, according to published research. SARS-CoV-2 (the coronavirus that causes COVID-19) is in the size range of 65­–125 nm, so some virus particles could slip through these coverings. Also, because of shortages, many health care workers have had to wear the same N95 mask repeatedly, even though they are intended for a single use. To help overcome these problems, Muhammad Mustafa Hussain and colleagues wanted to develop a membrane that more efficiently filters particles the size of SARS-CoV-2 and could be replaced on an N95 mask after every use.

A replaceable nanoporous membrane, illustrated above, attached to an N95 mask filters out particles the size of SARS-CoV-2 (purple circles), allowing only clean air (blue circles) through.

Credit: ACS Nano 2020, DOI: 10.1021/acsnano.0c0397

To make the membrane, the researchers first developed a silicon-based, porous template using lithography and chemical etching.

They placed the template over a polyimide film and used a process called reactive ion etching to make pores in the membrane, with sizes ranging from 5-55nm.

Then, they peeled off the membrane, which could be attached to an N95 mask. To ensure that the nanoporous membrane was breathable, the researchers measured the airflow rate through the pores.

They found that for pores tinier than 60nm (i.e. smaller than SARS-CoV-2), the pores needed to be placed a maximum of 330 nm from each other to achieve good breathability.

The hydrophobic membrane also cleans itself because droplets slide off it, preventing the pores from getting clogged with viruses and other particles.

https://pubs.acs.org/doi/abs/10.1021/acsnano.0c03976

TTG has Efficient Membrane Media for Masks

TTG’s proprietary membranes have helped guard medical personnel and medical equipment for years. The latest AIRADIGM™ innovation takes health care worker and patient protection to the next level. Merging expertise in filtration and membrane engineering with experience in performance fabric design, TTG has created a new AIRADIGM composite medical face mask medium that delivers an incomparable value equation that includes comfort, longevity, durability, and sustainability.

Three Layers of Protection
AIRADIGM’s composite face mask material is a proprietary construction that features:

• Spun-lace polyester on the outside
• ePTFE membrane in the center
• Spun-bond polypropylene on the inside
• Three layers sonically laminated for integrity and durability

The new AIRADIGM composite fabric TG77007 meets N95 surgical mask and ASTM Level 3 criteria for face mask media that offer the highest levels of protection against particulates, microbes, and fluids. *

Comfort and Performance
Studies have shown that PPE comfort is a must for compliance and concentration, both of which are absolutely critical in healthcare settings. Just like in performance apparel, AIRADIGM membranes keep fluids out but allow body heat and vapor to escape so that the wearer stays comfortable for the long term. Also, the composite fabric’s membrane core supports breathability without compromising protection.

This unique AIRADIGM composite medical face mask fabric provides filtration capabilities that do not degrade with humidity the way that traditional mask materials do. Microbe and particle protection levels stay consistently high for all-day protection without frequent mask replacements.

Durable and Sustainable
In addition to protecting for longer periods of time than traditional face masks, masks made with the special AIRADIGM composite material can be cleaned in an autoclave and safely reused. That relieves the stress on the PPE supply chain and improves return on investment, not to mention that substantially fewer masks end up in the landfill.

AIRADIGM membranes and composite fabrics are manufactured by TTG in the United States in a clean, resource considerate, state-of-the-art facility for the highest quality, quickest customer support, and most reliable deliveries.

*Click here for AIRADIGM’s TG77007 composite medical face mask material technical specification sheet.

ePTFE Membranes - Application in High-End Face Masks

With the recent advent of Covid-19, there is a significant strain on resources pertaining to either the prevention or containment of the virus. 

One of the key shortages highlighted has been around face masks, where some experts have suggested that if the pandemic continues to wreak havoc, the US presently has only 1% of the face masks it would need.

This shortfall has led to opportunistic behavior, such that the price of face masks has more than quadrupled in the past three weeks. As a result, good quality masks are not only scarce, but are being sold at an unimaginable premium.

Poly Fluoro Ltd  ePTFE membranes have advantages as mask media.

While ePTFE itself is not a low-cost material, its application in face masks could be revolutionary and allow for a very effective product in fighting the current crisis. The reasons for this are as follows:

1. Permeability – ePTFE has a unique property of being impervious to liquids, but permeable to gases. Since Covid-19 is known to be spread by droplets in the air, ePTFE forms an ideal medium to arrest the passage of droplets
2. FDA approved – as PTFE is an FDA approved material, it poses no risks to being used in face masks. Indeed, PTFE is one of the few materials that is approved for insertion into the human body, making it completely safe for such an application
3. Hydrophobic – not only is ePTFE resistant to droplets, but it is also hydrophobic in nature, meaning that droplets that do reach it are immediately repelled. Hence, there is less risk that an infected droplet would remain on the surface of the material. This allows the face mask to have a longer lift, as there is less chance that the infection stays on the surface of the material.
4. Low cost – as mentioned, ePTFE is itself an expensive material. However, when used in a small quantity – such as would be needed in a face mask – the price is negligible when compared with standard face masks

With the current crisis in play, it is essential that newer and more effective materials are brought into action. ePTFE is one such material, as it can be manufactured in bulk and embedded into a standard non-woven polypropylene mask to give a manifold improvement in protection, while adding very little in terms of cost.

By the company’s estimate, a simple ePTFE lined face mask should cost nothing more than US$0.2 per piece – which is a far cry from the US$2-3 we are currently seeing for high-end masks on the market.

Poly Fluoro Ltd has been at the forefront of polymer innovation, pioneering the manufacture and application of engineering plastics since 1985. Integrating in-house processing techniques with innovative machining and fabrication capabilities, they have developed a unique range of products tailored to suit numerous applications.

Poly Fluoro partners with over 100 Original Equipment Manufacturers (OEMs), supplying value-added products in PTFE, PEEK, Delrin, Nylon, and a range of other high-performance polymers.

Over the years, the company’s specialty products have become synonymous with the most reliable and robust engineering plastics for OE fitment. Operating out of a 20,000 square foot plant, they are an accredited ISO 9001 company that offers end-to-end design, prototype, and production services.

The company manufacturing facility is equipped with the capacity to mold, extrude, expand, and machine polymers in sizes ranging from 10mm to 500mm in diameter. Specializing in both virgin and formulated grades, they offer end-products ideally suited for use in original equipment and industrial maintenance.

DHA Uses Same Media for Masks and Gas Turbine Inlet Filters

DHA Filter has been in industrial filtration for more than three decades.

Like so many companies, the Coronavirus pandemic has had a dramatic impact on how it does business. As a filtration media producer, DHA began receiving inquiries as early as January by face mask manufacturers looking to procure meltblown polypropylene.

Up to this point, this has been the preferred material for face mask construction. As the volume of requests rapidly increased, it became clear that the supply of this material was going to fall well short of global demand.

DHA began the search for alternative materials that might yield similar if not superior filtration properties. Immediately it became apparent that the DHA proprietary HEPA grade, low resistance PTFE membrane developed for gas turbine inlet filters would be a viable option.

DHA reworked the membrane with approved base support materials to quickly enter the PPE arena. The underlying technology is an PTFE face mask membrane that acts as the mask’s efficiency layer.

It is encompassed by a layer of spunbond polypropylene on either side to complete the composite used to make the masks. In lab testing the material proved to be 99% efficient at filtering particles 0.1 micron and larger. This exceeds the standard for materials used in typical PTFE face mask. The material is also 100% hydrophobic which aids in creating an impenetrable barrier against droplets and spray.

FEATURES

• 100% Hydrophobic, preventing transfer of fluids
• Filters 99% of particulate matter
• Breathable, lightweight PTFE membrane for comfort
• Spunbond support layer resists tearing and shredding
• Sonically welded construction for durability
• Flexible metal nose piece ensures secure fit
• Low air resistance allows for uninhibited breathing
• Suitable for all day wear

 

TEFM Provides ePFTE Membranes for Masks

TEFM is made of ePTFE microporous material by unique nano-technology. The PTFE membrane has a micropore structure with small pore size, high porosity and irregular permutation. The efficiency for diameter 0.3 um particulate can be above 95%. It has excellent performance to block PM2.5 particulate, dust mite, virus & bacteria. The PTFE filtration membrane with a wide application, such as N99, N95, KF94, FFP3 mask, medical masks is reusable.

The masks retain performance after repeated washing, especially after laundering with surfactants and at high temperatures, but performance may differ from the laboratory tests. Hence, while antimicrobial masks can offer additional protection against microbes, basic hygiene practices such as not touching the mask surface and washing of hands should still be observed.

 

Membranes for Mask Supplied by Cobetter

Cobetter is a Chinese company supplying PTFE membranes for masks. The advantages are explained at https://www.cobetterfiltration.com/Industries/Medical/Mask/mask-membrane-PTFE/

 Founded in 2003, Cobetter is an international company headquartered in Hangzhou, China with over 1500 employees and nearly 100,000 square feet of filtration production area cleanroom space. With over 1,200 products and 100-patented technologies, Cobetter has developed a full product range composed of core materials with unique performance capabilities. Cobetter has implemented extensive quality control methods throughout their entire manufacturing process for their filtration products. These measures ensure the products are high quality, stable, and reliable in accordance with ISO 9001, 13485, 14001, and OHSAS 18001 standards. One of Cobetter’s core competencies is their membrane technology which they develop and manufacture in-house.

The Cobetter representative in the U.S. and Singapore is Banner Industries. It was founded in 1985 to serve a rapidly expanding high purity market and to satisfy the increasing demand for high-quality components with fast delivery at competitive prices.

BYU Develops Nanofiber Mask

The cloth masks many are sporting these days offer some protection against COVID-19. However, they typically provide much less than the professional N95 masks used by healthcare workers.

That may soon change. Recently, students from BYU’s College of Engineering teamed up with Nanos Foundation to develop a nanofiber membrane that can be sandwiched between the cloth pieces in a homemade mask.

While today’s typical cloth mask might block fewer than 50% of virus particles, the membrane — which can be made using simple, inexpensive materials — will be able to block 90 to 99% of particles, increasing effectiveness while preserving breathability.

The membranes are made through a process called “electrospinning,” which involves dissolving a polymer plastic in a solution and then using an electrical current to move a droplet of the polymer downward through a needle. As the droplet accelerates, it stretches into a very small fiber that retains a static charge.

“Those nanofibers randomly land on a collector to create a sort of non-woven mesh,” said Katie Varela, a BYU mechanical engineering senior on the project team.

The remaining charge in the fibers is beneficial, she explained, because virus particles also have a static charge. “When they come close to your mask, they will be statically attracted to the mask and will not be able to go through it, and so it prevents you from inhaling viruses.”

Liquid polymer is stretched out to create nanofibers used to increase the efficiency of cloth masks.

In addition to the dramatic improvement in efficacy, another key benefit of the nanofiber masks is that unlike traditional N95 masks, which have a reputation for being hot and stuffy, they allow for the circulation of (filtered) air, water, and heat.

“Not only is it hard to find an N95 mask these days, but the best mask is useless if you won’t wear it,” said Will Vahle, director at Nanos Foundation. “Our nanofiber membranes are six times easier to breathe through than existing N95 masks, making them cooler, drier, and more comfortable.”

The group plans to make the instructions for creating the membranes open source. They hope that non-profit organizations will use the instructions to set up local sites where people can bring in their masks to be fitted with a membrane. They also hope other engineers will use their work as a springboard to produce more effective filters.

“We had our own proprietary nanofiber production process,” said Vahle of the project’s origins, “but we realized, hey, we have some expertise in this — why don’t we get this together and release a version that anybody can do?”

When Vahle and his colleagues approached BYU to collaborate on the project, BYU “jumped at the opportunity,” Vahle said. In addition to providing funding and facilities, the university connected the company with “fantastic students, who’ve really demonstrated an incredible work ethic and a drive to help people in need.”

Using cutting-edge science to make an immediate positive impact has also been highly valuable for the BYU students on the project.

“This experience makes things very real,” said Varela. “I’m really glad that I’m able to help with this fight against COVID-19 to help people all around the world and in my community.”


Nanofiber Media Reduces Face Mask Resistance

This was the conclusion of researchers from Stony Brook University

Potentially infected individuals (‘source’) are sometimes encouraged to use face masks to reduce exposure of their infectious aerosols to others (‘receiver’). To improve compliance with Respiratory Source Control via face mask and therefore reduce receiver exposure, a mask should be comfortable and effective. the researchers tested a novel face mask designed to improve breathability and filtration using nanofiber filtration.

Using radiolabeled test aerosols and a calibrated exposure chamber simulating source to receiver interaction, facepiece function was measured with a life-like ventilated manikin model. Measurements included mask airflow resistance (pressure difference during breathing), filtration, (mask capture of exhaled radiolabeled test aerosols), and exposure (the transfer of ‘infectious’ aerosols from the ‘source’ to a ‘receiver’). Polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm. Tested facepieces included nanofiber prototype surgical masks, conventional surgical masks, and for comparison, an N95-class filtering facepiece respirator (commonly known as an ‘N95 respirator’). Airflow through and around conventional surgical face mask and nanofiber prototype face mask was visualized using Schlieren optical imaging.

Airflow resistance [ΔP, cmH₂O] across sealed surgical masks (means: 0.1865 and 0.1791 cmH₂O) approached that of the N95 (mean: 0.2664 cmH₂O). The airflow resistance across the nanofiber face mask whether sealed or not sealed (0.0504 and 0.0311 cmH₂O) was significantly reduced in comparison. In addition, ‘infected’ source airflow filtration and receiver exposure levels for nanofiber face masks placed on the source were comparable to that achieved with N95 placed on the source; 98.98% versus 82.68% and 0.0194 versus 0.0557, respectively. Compared to deflection within and around the conventional face masks, Schlieren optical imaging demonstrated enhanced airflow through the nanofiber mask

Substituting nanofiber for conventional filter media significantly reduced face mask airflow resistance directing more airflow through the face mask resulting in enhanced filtration. Respiratory source control efficacy similar to that achieved through the use of an N95 respirator worn by the source and decreased airflow resistance using nanofiber masks may improve compliance and reduce receiver exposure.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4090760/

Properties of commercially available antimicrobial masks. Compared.

Anti-microbial masks were compared in a study linked below. Here is a summary.

^aMedical and/or FDA classification. OUK = FDA clearance as a surgical mask with antimicrobial/antiviral agent; ONT = FDA clearance as an N95 mask with antimicrobial/antiviral agent. Washable/reusable masks do not require any certification. ^bAntimicrobial tests were performed only on fabric but not directly on the masks. ^cSingle HEPA filter provided with the mask is not washable or reusable. ^dReusable but not recommended to be laundered.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7429109/