Surgical face masks are made with non-woven fabric, which has better bacteria filtration and air permeability while remaining less slippery than woven cloth. The material most commonly used to make them is polypropylene, either 20 or 25 grams per square meter (gsm) in density.
Surgical masks are made up of a multi-layered structure, generally by covering a layer of textile with non-woven bonded fabric on both sides. Non-wovens, which are cheaper to make and cleaner thanks to their disposable nature, are made with three or four layers. These disposable masks are often made with two filter layers effective at filtering out particles such as bacteria above 1 micron.
Masks are made on a machine line that assembles the nonwovens from bobbins, ultrasonically welds the layers together, and stamps the masks with nose strips, ear loops, and other pieces.
Respirators also consist of multiple layers. The outer layer on both sides is a protective nonwoven fabric between 20 and 50 g/m2 density to create a barrier both against the outside environment and, on the inside, against the wearer’s own exhalations. A pre-filtration layer follows which can be as dense as 250 g/m2. This is usually a needled nonwoven which is produced through hot calendaring, in which plastic fibers are thermally bonded by running them through high pressure heated rolls. This makes the pre-filtration layer thicker and stiffer to form the desired shape and keep it as the mask is used. The last layer is a high efficiency meltblown electret nonwoven material, which determines the filtration efficiency.
Spunbonding is a process by which fabrics are produced directly from a thermoplastic polymer such as polyester, nylon, polypropylene, or polyethylene.
The molten polymer is extruded through a spinneret, cooled slightly in the air, and laid on a moving conveyor belt to form a continuous web. As the web cools, the fibers bond.
Spunbond fabrics are produced by depositing extruded, spun filaments onto a collecting belt in a uniform random manner followed by bonding the fibers.
Our Spunbound process is continuously running so there is always a team of technicians keeping the quality consistent.