This year was marked by the coronavirus pandemic, the common name used to describe the pandemic of COVID-19. This is a disease caused by a new species of respiratory virus previously unknown to experts in the field. At first, the virus seemed pretty harmless, but by now we know that it can be severe and potentially lethal in certain groups of people. This is the reason why the focus has been on stopping the spread of the virus, to prevent the collapse of healthcare systems and deaths around the world.
N95 masks have been the best face masks for virus protection, and a highly valuable resource for healthcare workers. In this article, we’ll discuss them further, and how polypropylene is used by 3M, one of the main manufacturers of medical supplies, to make them
What are N95 masks?
Inside the United States, there’s an institution responsible for setting the standards and regulating respirators intended to be used as personal protective equipment (PPE). The National Institute for Occupational Safety and Health (NIOSH), a federal agency part of the Centers for Disease Control and Prevention (CDC), does this as part of their goal to make recommendations based on science and research to prevent work-related diseases or injuries.
To do this, they’ve established a classification for respirators based on two characteristics:
- Oil-resistance: respirators can be either not resistant (‘N’), somewhat resistant (‘R’), or oil-proof (‘P’).
- Filtration rate: this is based on the percentage of minimum particulate filtration efficacy, which can be 95, 99, or 100%.
Based on this classification, when a manufacturer makes a respirator intended to be an N95 one, it means that the respirator isn’t resistant to oil, and can filter out at least 95% of the airborne particles in the air. This makes them effective for non-oil based airborne particles, such as dust, smoke, and certain bioaerosols like the flu virus or the SARS-CoV-2, the virus responsible for COVID-19.
They offer more antiviral properties than reusable cloth masks or surgical and medical masks. Anyone who uses N95 masks, which can be used with face shields, is having the highest protection possible from a face mask. KN95 masks, their equivalent under the Chinese filtration standards, have also been used during the pandemic as a substitute for them during shortages, many of them obtaining special approvals by the FDA (Emergency Use Authorizations) to be used in healthcare settings during the pandemic.
How is polypropylene used by 3M and other major companies to make N95 masks?
3M is one of the main manufacturers and distributors of medical supplies and PPE around the world and inside the USA. They’ve been ramping their production of N95 masks, one of the most important and scarce resources for virus protection, and are on track to meet their goal of producing 2 billion N95 masks this year. Some of the most popular 3M N95 mask models include the 3M 8210 and 3M 8511.
N95 masks can be produced with different materials, but the most used one is without a doubt polypropylene. This is a thermoplastic material, which means that, when exposed to high temperatures, it can be molded, and then it will solidify in that position when the temperatures are lower.
The term ‘polypropylene’ means that it’s a polymer of propylene, which is just a fancy way of saying that it’s made with lots of propylene molecules. It’s a hydrocarbon, meaning that it’s obtained from fossil molecules, that is highly used in the textile industry as a raw material. It’s the second most used plastic in the world, with the first one being polyethylene.
Factories produce a fabric known as ‘non-woven fabric’ using polypropylene. Another name used to refer to it is ‘melt-blown material’. This is a fabric that doesn’t require weaving techniques, used widely in the textile industry because it’s lightweight and highly resistant to certain environmental conditions.
The non-woven material is used to make up the filter of N95 masks. This fabric has a lot of pores that are small enough to trap airborne particles, which have a diameter of 0.3 microns. This way, the particles don’t enter the airways of the user. However, N95 masks need to meet breathability requirements too, and with such small pores, breathing can be difficult.
To solve this problem and meet both filtering and breathability requirements, manufacturers like 3M use other filtration techniques so that the pores can be a little bigger, allowing the user to breathe correctly. The most widely used technique is electrostatic filtration, and the principle of this method is that the charges added to the filter media will attract particles with an opposite charge, whether they’re large or small. Since polypropylene doesn’t naturally have an electrostatic charge, it has to be added to it during the manufacturing process.
Melt-blown material offers many good properties to N95 masks, but it isn’t very durable, which is why N95 masks are disposable face masks and need to be discarded after 8 to 12 hours of use. After this lifespan, N95 respirators lose their filtration properties, and they’re not as effective. This is due to the degradation and the loss of the electrostatic charges of the non-woven fabric.
We always like to remind our readers to stay protected in public during these trying times, to help the most vulnerable people in our communities face the virus. You can find options for face-covering for sale online, which you can buy in bulk or wholesale, and a smaller size for kids as well.