Coronavirus Technology Solutions

August 7, 2020

Evaluating Co-benefits of Masks and Filters for COVID and Other Contaminants

Verdex Nanofibers have Advantages in Masks and Air Filters

Hifyber Nanofiber Masks Combine High Efficiency and Comfort

Fibertex Nonwovens has Nanofiber Products for Both Face Masks and HVAC Filters

Clean Recirculating Air Not Sanitation Should be the Top Priority for Schools

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Evaluating Co-benefits of Masks and Filters for COVID and Other Contaminants

It is hard to visualize that we inhale and exhale millions of particles every minute. It seems impossible to comprehend how our lungs can function given this particle barrage. It starts to come into perspective when you learn that the weight of particles you inhale are very minimal where ambient particle levels meet the WHO limits.  Nevertheless since COVID is also tiny the numbers of small particles become meaningful.

The air pollution industry relies on weight to measure pollution. In fact a HEPA filter is used to measure air pollution efficiency. If zero weight of particles is caught in the HEPA filter then the assumption is that the pollution is zero. The cleanroom industry doesn’t concern itself with weight. If there is enough weight to measure it is a very unclean room. In fact the efficiency of HEPA filters is determined by particle count. So the message from the cleanroom to the air pollution industry is that the absolute filter is not absolute.

COVID attaches to particles. Also one way to evaluate COVID reduction is to measure the particles in the air before and after filtration. Pharmaceutical cleanrooms rely on the particle measurements as a surrogate for virus and other microbial contaminants. A class 100 cleanroom reduces the number of 0.5 microns down to 3500/m3 or 100 per ft2. By contrast room air has more than 35 million 0.5 micron and larger particles per cubic meter.  So there is a10,000 time reduction. A Class 1 cleanroom which would be used for vaccine filling would reduce particulate to just 35 particles 0.5 microns and larger.

The prevailing efforts in selection of masks and filters only reduce 0.5 micron particles to somewhere still in the millions/m3.

More insights are needed relative to the very large number of particles in the atmosphere and therefore inhaled along with the virus.
In our July 27 Alert we analyzed room air.
 

The average individual in a room of average air purity will breath in and exhale many millions of particles every minute. Here are the particles by size in each breath.

We have thought to extrapolate these numbers for an individual location based on the air quality measured in mg/m3.  But we find out that just because Delhi has 23 times the WHO ambient PM 2.5 limits deemed you cannot predict that a person will breath in and out 23 times as many ultra-fine particles.

A recent study addressed the question “Can mitigating only particle mass, as the existing air quality measures do, ultimately lead to reduction in ultrafine particles (UFP)? The aim of this study was to provide a broader urban perspective on the relationship between UFP, measured in terms of particle number concentration (PNC) and PM_2.5 (mass concentration of particles with aerodynamic diameter < 2.5 μm) and factors that influence their concentrations. Hourly average PNC and PM_2.5 were acquired from ten cities located in North America, Europe, Asia, and Australia over a 12-month period. A pairwise comparison of the mean difference and the Kolmogorov-Smirnov test with the application of bootstrapping were performed for each city. Diurnal and seasonal trends were obtained using a generalized additive model (GAM). The particle number to mass concentration ratios and the Pearson's correlation coefficient were calculated to elucidate the nature of the relationship between these two metrics.

Results show that the annual mean concentrations ranged from 8.0 × 10³ to 19.5 × 10³ particles·cm⁻³ and from 7.0 to 65.8 μg·m⁻³ for PNC and PM_2.5, respectively, with the data distributions generally skewed to the right, and with a wider spread for PNC. PNC showed a more distinct diurnal trend compared with PM_2.5, attributed to the high contributions of UFP from vehicular emissions to PNC. The variation in both PNC and PM_2.5 due to seasonality is linked to the cities' geographical location and features.

Clustering the cities based on annual median concentrations of both PNC and PM_2.5 demonstrated that a high PNC level does not lead to a high PM_2.5, and vice versa. The particle number-to-mass ratio (in units of 10⁹ particles·μg⁻¹) ranged from 0.14 to 2.2, >1 for roadside sites and <1 for urban background sites with lower values for more polluted cities. The Pearson's r ranged from 0.09 to 0.64 for the log-transformed data, indicating generally poor linear correlation between PNC and PM_2.5. Therefore, PNC and PM_2.5 measurements are not representative of each other; and regulating PM_2.5 does little to reduce PNC. This highlights the need to establish regulatory approaches and control measures to address the impacts of elevated UFP concentrations, especially in urban areas, considering their potential health risks.

https://www.sciencedirect.com/science/article/pii/S0160412019311110

There is the need to evaluate COVID mitigation as a function of particulate reduction. This is made more difficult by the finding that all of our knowledge about air pollution based on weight can not be converted easily to particle counts.

Verdex Nanofibers have Advantages in Masks and Air Filters

Verdex is a technology company specializing in mass production of nanofibers for extensive end use applications including air and microfiltration media, high efficiency fuel filtration, advanced filtration, microporous breathable films, micron rated venting films, life sciences/pharmaceutical medias, acoustics, face masks, performance apparel and much more.

Verdex has the ability to spin polymers such as PCL, PLA, PP, PET, PBT, Nylon 66, and possible others if melt viscosity is low. This versatility combined with a unique ability to simultaneously spin multiple polymers without using solvents provides unprecedented flexibility.

The combination of efficiency and high dust holding capacity makes Verdex HVAC filter technology a choice for commercial HVAC or clean room applications. Technology is capable of achieving efficiencies up to e12 or MERV 12-16. With lower pressure drop and none of the heath concerns posed by traditional microglass composite medias. 

Depending on application, the nanofiber layer can be placed on either upstream or downstream surface, or as a middle layer of the composite structure. Verdex HVAC technology is insensitive to humidity, meaning it is able to retains its filtration efficiency and low pressure drop throughout the life of a filter regardless of the temperature and the humidity. Technology is the most innovative and sustainable filtration media across the global HVAC.

Face Masks Verdex’s nanofiber incorporated face mask technology is very easy to breathe through due to its extremely wide surface area created by the web of nanofibers. It is very effective at mechanically filtering out PM2.5 particulates.

Conventional electrostatic filter masks’ filtration efficiencies decline dramatically after it becomes discharged, whereas a nanofiber face mask provides consistent high efficiency filtering ability regardless of external environment.

The  filter material is comprised of a series of activated carbon filaments, each about 2,000 nanometers in diameter. Each filament is many times smaller than the typical grain size in standard carbon materials, making the rate of adsorption of pollutant gas much faster and therefore more powerful. It also means that bacteria and viruses are drawn to the filament surface much more efficiently, because there is so much more available surface than in a granular carbon.

Verdex Face Mask Technology therefore works as powerful respirators that not only clear the air of pollution via the particulate filter, but also remove potentially harmful gases and pathogens with the additional carbon filter.

Hifyber Nanofiber Masks Combine High Efficiency and Comfort

In response to the Covid-19 pandemic, HIFYBER has developed a nanofiber facemask media, HF-SPS50-FFP series produced with the proprietary electrospinning nanofibers and multilayer design which provides exceptional breathability and comfort over long periods of use.

The CDC recommends an N95 filtering facepiece respirator (FFR) respirator which filters out at least 95% of very small (0.3 micron) particles, including bacteria and viruses.

Hifyber has various facemask filter media options that effectively capture up to 99% of 0.3 micron particles and achieves 99.7% (BFE) / 99.9% (PFE) filtration performance. HF-SPS50-FFP2 and FFP3 materials have been tested and certificated by Nelson Labs and NC State University's Nonwoven Institute in the USA. Full reports are available in below links:

http://www.hifyber.com/images/technical/BFE-Final-Report-HF-SPS50-FFP2-13.04.2020.pdf

http://www.hifyber.com/images/technical/BFE-Final-Report-HF-SPS50-FFP3-13.04.2020.pdf 

Advantages :

- %99,7 Bacterial Filtration Efficiency and %99,9 Particle Filtration Efficiency-

- The unique media design provides easy breathability andwearer comfort

- No artificial static charge , it's mechanically efficient

- High Surface Area

- Excellent Durability and Long Lifetime

Hifyber production capacity is over 1 million m2 per month for the N95 grade facemask.

Fibertex Nonwovens has Nanofiber Products for Both Face Masks and HVAC Filters

Fibertex Nonwovens expects to generate full-year 2020 revenue of DKK 1,750 million and EBITDA in the range of DKK 165-185 million. Fibertex Nonwovens felt the effect of the general economic decline in Europe during the final months of the year, and the reported revenue of DKK 373 million for the fourth quarter of 2019 was in line with the figure for the fourth quarter of 2018. Full-year revenue still improved by 8% to DKK 1,705 million, up from DKK 1,574 million in 2018. The revenue improvement was due primarily to the acquisition of the US spunlace business in January 2019, which contributed DKK 140 million, and generally to growth in North America, whereas tough competition and subdued demand weighed on performance in the European markets.

In recent years, Fibertex Nonwovens has consolidated its position as a leading manufacturer of industrial nonwovens, and in 2019 the company has strengthened its business base by making a number of important strategic and structural initiatives. In addition to acquiring the US spunlace operations and expanding capacity by relocating the needlepunch production line from South Africa, these initiatives have included starting up nanotechnology applications, restructuring production in the Czech Republic and Turkey, and optimizing production across its European sites. In terms of development and innovation, the company has built a solid portfolio of new projects, including new products for the automotive and composite industries and for filtration and acoustic purposes, while steadily expanding capacity and upgrading production lines in order to increase the proportion of value-added products.

The filtration market is turning out to be one of the most promising markets for Fibertex Nonwovens. The company’s new filtration media offer higher filtration efficiency with less pressure drop than in conventional filtration products. The greater active surface area of the nanofibres and minute deviations in pore size ensure very high filtration material performance. Potential applications for these nano-based filtration products include liquid and air filtration, to filter out bacteria or pollen, for example. The fibres in the nanoproducts have a thickness of only 100 nanometres, whereas ordinary nonwoven fibres are about 100 times thicker.
 
“We see a huge potential in the filtration market, and our ambition is to become a leading global player capable of manufacturing filters with a wide range of different properties. In addition, we have the facilities to produce these products under fully controlled and certified production conditions ensuring environmentally-responsible and sustainable production,”  says Jørgen Bech Madsen.
  

FACE MASKS AND RESPIRATORS MEDIA

Treatments:
Possible treatment options of Polyester and Spunbond media are:
Hydrophopic/Oleophopic or Antimicrobial

Possible treatment options of Polyester/Polypropylene media are:
Antistatic, Hydrophopic/Oleophopic or Antimicrobial

Treatments:
Possible treatment options of Spunbond soft feel media are:
Hydrophopic/Oleophopic or Antimicrobial
(Does not apply for 100% Polyester soft feel N95 ASTM F2100-11 Standard)

Clean Recirculating Air Not Sanitation Should be the Top Priority for Schools

Alexandra Feathers is an epidemiologist, mother and medical student. In a Stat article she asks very relevant questions as to why is ventilation not the top priority at schools? Since is it very likely that cloth masks are aerosol generators and that most transmission is through aerosols the ventilation system with efficient filters should be the top priority.  The use of N95 masks should be of equal priority.  Here are her questions.

“My school is not negligent, but like many other educational institutions, its efforts are dangerously misdirected. We are collectively engaging in what Derek Thompson describes in the Atlantic as “hygiene theater,” in which organizations looking to reopen focus intensively on arduous decontamination strategies to mitigate surface transmission — even though that is not the primary route for Covid-19 transmission, and some scientists argue that there is no direct evidence the virus spreads this way at all. I’d also like to add temperature checks to the hygiene theater playbill, as they too fail to successfully screen potential Covid-19 carriers but have somehow made their way onto every screening list I’ve seen.

Why is this happening? The CDC is supposed to determine the national priorities for American health.

Of the eight bullet points in its “staff safety” section, four address surface transmission. The three bullet points dedicated to respiratory droplets warn people to stay 6 feet away from each other, cough into their elbows, and wear a mask.

The current CDC guidance about ventilation is as follows, “Ensure ventilation systems operate properly and increase circulation of outdoor air as much as possible, for example by opening windows and doors.” But if opening windows or doors increases the risk  of asthma, or falling out the window, the guidelines go on to advise that they should be closed. That is all the guidance has to say. It does not mention air filtration, or the fact that we have pretty good data to suggest that without addressing air filtration and circulation, the 6-feet rule 

HEPA filters are able to effectively capture particles the size of SARS-CoV-2. The CDC currently recommends their use for this purpose in hospitals, but their capacity to prevent the spread of Covid-19 in other public buildings remains under-explored. Though the CDC has stayed silent on the use of HEPA filters outside hospitals, on May 25 a group of ENT doctors made the case for installing them in doctors’ offices where “aerosol generating procedures” are being performed, because of evidence they can help prevent the spread other infections such as SARS-CoV-1, measles, and influenza. That was published 108 days before the first day of school in New York City.

On May 27, a group of 36 scientists from around the world in a variety of fields penned an article in the journal Environment International titled, “How can airborne transmission of Covid-19 indoors be minimized?” As they wrote, “Here, in the face of such uncertainty, we argue that the benefits of an effective ventilation system, possibly enhanced by particle filtration and air disinfection, for contributing to an overall reduction in the indoor airborne infection risk, are obvious.” It’s obvious to me as well and deserves to be our primary concern in reopening schools, far more urgently than distance or Lysol. That was 106 days before the first day of school in New York City.”

https://www.statnews.com/2020/08/05/ventilation-part-of-school-reopening-conversation/