What are non-woven fabric masks made of?

The main raw material for non-woven masks is polypropylene (PP) fiber, which is widely used in different functional layers of the mask: spunbond polypropylene is often used to make the strong and breathable outer and inner layers, while electrostatic meltblown polypropylene forms the crucial high-efficiency filtration layer (such as the core layer of N95 masks). In addition, materials such as polyester fibers, natural fibers (such as linen and cotton), and activated carbon for odor absorption can also be used to produce medical or daily protective masks of different protection levels, forming a multi-layer composite structure (such as SMS composite material).

Polypropylene, as a thermoplastic plastic, possesses excellent chemical stability, corrosion resistance, and processing performance. It is made into non-woven fabric through meltblown or spunbond processes, which are the core technologies in the production of non-woven mask fabrics. Non-woven fabrics produced by the meltblown process have finer fibers and higher filtration efficiency, and are mostly used as the intermediate filtration layer of medical masks; non-woven fabrics produced by the spunbond process have better strength and are usually used for the outer and inner layers of masks. To further improve performance, antibacterial agents and electrostatic electret materials may also be added during production to improve filtration efficiency and wearing comfort. The production process and raw material selection of non-woven mask fabrics directly affect the protective performance and user experience of the mask, therefore, there are strict requirements for the quality of raw materials.

The specific composition of non-woven masks varies depending on the type and protection level, but usually uses non-woven fabric as the core material. Its main structure can be divided into the following parts:

Main structure: Usually made of non-woven fabric, there are two common forms: one with a surface of pure cotton degreased gauze or knitted fabric, with non-woven fabric in the middle; the other is directly sewn from non-woven fabric.

Filtration layer: Protective masks usually have a meltblown non-woven fabric as the core filtration layer in the middle layer to block particles. Some masks use a three-layer non-woven fabric structure (such as SMS: spunbond-meltblown-spunbond), where the outer layer is waterproof, the middle meltblown layer performs the filtration function, and the inner layer focuses on moisture absorption and skin-friendliness.

Nose clip: The upper edge of the mask is equipped with a nose clip, generally made of a malleable material (such as a metal strip or environmentally friendly plastic strip), usually no less than 8.5 cm in length, to ensure a tight fit between the mask and the bridge of the nose, improving overall sealing.

Mask straps: Used to secure the mask, often made of non-woven fabric straps, elastic bands, or other elastic materials. The connection points must have sufficient strength.

Other auxiliary materials: Depending on the design requirements, these may also include medical degreased gauze, aluminum strips (for nose clip shaping), dyes, or shaping cotton.

The structure of masks also varies depending on the usage scenario: everyday protective masks have a relatively simple structure, possibly consisting of only a single layer or a double layer of non-woven fabric; while medical or high-efficiency protective masks (such as disposable medical masks) usually adopt a multi-layer design, emphasizing a three-layer protective structure with a waterproof outer layer, a filtering middle layer, and a moisture-absorbing inner layer.