WIN-Masks: washable innovative nano-masks introduced to prevent COVID-19

The Thailand Center of Excellence for Life Sciences (TCELS) under the Ministry of Higher Education, Science, Research and Innovation in partnership with the Faculty of Medicine, Siriraj Hospital, Mahidol University, Rajamangala University of Technology Lanna and the Thailand Institute of Nuclear Technology (Public Organization), recently announced a breakthrough in the research & development of WIN-Masks, new innovative nano-cotton masks to protect against COVID-19.

Developed with the support of the National Research Council of Thailand (NRCT), the WIN-Masks are made from anti-dust and anti-mite woven fabric with 4-5 microns of pore size and thus keep the wearer safe from dust mites and respiratory droplets. The masks can be used repeatedly after washing and disinfection. The fabric is water-repellent to prevent the droplets and contains zinc oxide (ZnO) to inhibit bacteria growth.

The WIN-Masks could be an alternative for healthcare workers who do not come into direct contact with confirmed COVID-19 cases, officials working in low-risk areas and those living in congested communities or whose work requires them to be in crowded areas. In addition to protecting against COVID-19 infection, the WIN-Masks will also help reduce contamination from the disposal of single-use masks.

The TCELS has also prepared for technology transfer to producers of fabric face masks that meet quality standards. The production of and further innovations to the WIN-Masks will be undertaken through crowd funding.

The TCELS has also prepared for technology transfer to producers of fabric face masks that meet quality standards. The production of and further innovations to the WIN-Masks will be undertaken through crowd funding.

Know the facts about coronavirus disease 2019 (COVID-19)

-COVID-19 particles measure between 0.05 and 0.2 microns in diameter or an average of 0.1 micron

-The virus can spread through respiratory droplets produced when an infected person coughs or sneezes, with other becoming infected when they touch their mouth, nose and possibly eyes. To prevent infection, people must wear face masks and wash hands with soap and water for at least 20 seconds before touching any part of their face and especially their mouth, nose or eyes.

-Most respiratory droplets produced from coughing or sneezing range in size from 50 to 100 microns. Droplets of 100 micron can be spread over a radius of 1-2 meters while the smaller 50 micron can spread to 4 meters. Droplets of 5 micron might spread as far as 8 meters.

-Infected persons without symptoms can spread the virus but they produce a lower viral load and thus the chance of spreading the infection is lower than in those with symptoms.

-Talking for just 5 minutes can release up to 3,000 respiratory droplets over a radius of one meter. To prevent infection, it is thus essential that people avoid crowded areas.

-The severity of disease will depend on the quantity of virus inhaled into lung tissue and the immunity of the infected person.

-Compared with other viruses, Coronavirus can live on various types of surfaces for up to 9 days. In temperatures of 40-degrees Celsius, the virus can survive for 4-96 hours and for more than one month in a refrigerator. People can clean their hands by using an alcohol-based hand rub that contains at least 70% alcohol and 0.1 sodium hypochlorite to kill the virus.

Face masks that protect against COVID-19 have the following properties:
1. Particle filtration efficiency to remove particle size of 5 micron.
2. Fluid resistance to protect wearers from respiratory droplets or bodily fluids.
3. Fit test to ensure a tight, effective and customized fit for your face to protect against airborne contaminants.
4. Permeability test that provides comfortable breathing with proper airflow.
Properties of Siriraj anti-dust mite masks
- The WIN-Masks are made from tightly-woven fabrics by using microfibers with a thread count of more than 270 per square inch.
- The mask has a fabric pore size of 4-5 micron which is smaller than a droplet.

The 3 key elements of WIN-Masks are:
1. It is a nano-coated cotton fabric to resist water and filter particle size of 5 micron.
2. Microfiber fabric containing ZnO to inhibit bacteria growth.
3. The masks are made from No.30 cotton to absorb body fluids and moisture produced by wearers.

Designed for face tight-fitting and comfortable wearing
-The concept adopted by the design team from TCELS aimed to create modern and comfortable-to-wear masks. They are available in 3 sizes: small, medium and large.

Test results of WIN-Mask performance

-Particle filtration efficiency
#Primarily, the mask is capable of filtering 65% of PM2.5, close to a surgical mask. The researchers are now developing a mask that will filter at least 80% of PM2.5.
-Fluid resistance efficiency
#Dropping water on the nano-coated fabric showed that the water particles did not go through fabric surface, and even be absorbed by or penetrate the fabric rather like lotus leaves.
-Face seal fit test
#Fit efficiency is a measure to indicate the mask’s efficiency  at filtering out airborne particles outside the mask. Test results showed that the Win-Masks have an efficiency of approximately 68% in preventing air from the outside compared to 62% filtration found in general face masks.
#The Fit Factor is 3.11, indicating that air quality within a mask is 3 times better than outside when worn by the general public. Its fit factor index is better than a normal face mask of 2.65.

-Permeability test
# Based on ISO 9235:1995 (E), the test result of the WIN-Masks by the Thailand Textile Institute indicated an average of 0.709 cubic centimeters per square centimeter per second. (Zero means no water permeability rate and 1 means highly efficient water influx through a fabric).
# Breathing tests on volunteers in an indoor working environment showed that they could wear the WIN-Masks for a long time without discomfort breathing.
#The mask can be washed many times without losing any of its properties.
# For the first use, the mask has an efficiency to filter out 34% of 0.3 micron particle size.
# After washing 30 times, the mask has an efficiency to filter out 45% of 0.3 micron particle size.
Note: The better filtration efficiency after washing might be the result of the effect on the properties of the cotton fabric and fibers enabling better filtration of dust.

The Win-Masks should be used by the following at-risk groups:
-Healthcare personnel who care for general patients, both outpatients and inpatients, but do not care for confirmed cases directly including doctors, nurses, pharmacists, those dealing with patient transfers, medical records, public relations and cashiers.
-Non-healthcare staff who deal with the public face-to-face including aircrew, taxi drivers and airport officials
-People who live in crowded areas or meet many persons during the course of the day.
In addition to wearing the masks, people must thoroughly wash their hands with soap and water or use 70% alcohol-based rub for at least 20 seconds every time before touching their nose, mouth and eyes. Strict attention to hygiene is also recommended including hot meals, using own spoons, separate food containers and dining equipment, and avoiding crowded areas. These are the best ways to protect oneself from infection.    

Caution, maintenance and cleanliness
-If the wearer feels any breathing discomfort, experiences a tight chest and fatigue, the mask should be removed.
-When torn, damaged or contaminated by droplets or fluids, a new mask should be worn.
-Keep the used fabric face mask in a plastic zip lock bag and tighten the back. Clean the mask by washing.
-The mask can be washed in clean water or warm water. A separate container is recommended.
-The mask should not be ironed as this can damage the performance of the nano coating.            


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