Cloth masks are made from tightly woven strands of fabric, layered over one another for added protection. This allows the mask to be reusable and makes for a very durable purchase. However, it isn’t the best mask out there available for purchase. The winner of that prize goes to the n95 mask, which can block out 95% of all particles that attempt to pass through the material that it is made from. That material? Polypropylene. A type of plastic that is safe to use around humans, polypropylene is a type of thermoplastic polymer. Thermoplastic refers to the fact that this plastic is easily shaped and molded when heated above a certain temperature, but will hold its shape once cooled. Polymers are a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. There are many varieties of both artificial and natural polymers, and they are used in many aspects of everyday life. Polypropylene is produced through a chain-growth polymerization from a monomer propylene, which is a large organic molecule. This material is widely produced as a commodity plastic, being the second largest polymer behind polyethylene, which is used mainly for packaging.
While polyethylene is used in packaging, polypropylene is used in a large variety of areas, from the lid and hinge of a tic tac box, to the seat of a plastic school chair, to many articles of clothing worn by people of all ages. Depending on how this plastic is treated, it can change the properties and therefore the uses of the polymer to fit a wide variety of possible applications. When it needs to be tough, like the box lid or the chair, the material can be made much stiffer, while it can be set much more flexible for other uses such as in diapers or cold-weather clothing. Then there are the medical uses for polypropylene.
It might be surprising to know that masks are not one of the most common uses for this thermoplastic polymer in the medical field. One of the most common uses is for the creation of suture thread, which is the fiber that is used to close wounds and cuts on flesh. This is because of the relative safety of the material when properly treated in contact with human skin and tissue. For this reason, polypropylene is also used to create mesh that can be grafted onto places to prevent unwanted growths such as hernias. Spunbond polypropylene is usually used for the creation of face masks, including n95 masks and surgical masks. This material is capable of stopping most particles from passing through it, making it an excellent layer to add to woven cloth and fabric.
All this means that polypropylene has been around for a long time, it has been tested and deemed safe by the CDC for use in the creation of n95 and surgical masks. This is a very good thing. As the second most produced plastic in the world, there is plenty of material to work with, so that when production of n95 masks increases, there won’t be any shortage of materials to make them from. This thermoplastic polymer is all around you, helping keep our daily lives running smoothly, so we all have to do our part and Mask Up!