Material requirements and related technologies of medical nonwoven masks

1. Commonly used basic raw materials and characteristics At present, the basic raw material of commonly used mask fabrics is polypropylene masterbatch, which has the advantages of low density and easy photodegradation. After the polypropylene non-woven fabric reaches a certain length of use, the macromolecular chain can be photodegraded and broken. It is suitable for disposable mask materials and can reduce environmental pollution. Polyester fiber has the advantages of high strength and good light resistance. Its high crimp hollow short fiber can be used for interlayer meltblown, which improves the dust holding capacity of the mask and reduces the filtering resistance of the mask. In addition, the modified basic raw materials can also improve the protection of masks. One method is to use modified PP or blend PP and functional masterbatch to spin. If microcapsule technology is used, the microcapsules with degrading agent as the core material are uniformly adhered to the fiber surface to prepare degradable non-woven fabrics. In addition, controllable degradation agent or nano-level photosensitive material powder is added to PP polymer for blending meltblown spinning, and the produced meltblown cloth has controllable light-biodegradability. The antibacterial agent (generally 5%-20%) can also be mixed into the spinning masterbatch, and the antibacterial non-woven fabric can be obtained after blending and spinning. 2. With the rapid increase in the amount of disposable medical masks used, biodegradable fiber materials will cause serious environmental pollution if a large number of masks cannot be degraded in time after being discarded. In order to alleviate the pressure of environmental protection, researchers have developed natural cellulose and bio-based polymers that are green, sustainable, and biodegradable. Natural cellulose and its derivatives, such as viscose, Lyocell, Viloft, chitin, and synthetic polymers, such as polylactic acid (PLA), are gradually being used in the production of nonwovens. The researchers used chitin nanofibers and lignin as raw materials, polyoxyethylene (PEOx) as the solvent, and electrospinning to fabricate degradable nanofiber membranes. After antistatic treatment, the film is placed between high-strength spunbonded fabrics to make a mask with protective properties. In order to further adapt to environmental protection requirements, Taiwan, China, Europe and the United States and other countries or regions have widely adopted bio-based polymers, such as bio-based polyethylene (PE), bio-based polyester, bio-based polypropylene, etc. to produce degradable environmentally friendly spunbonded fabrics and meltblown cloth. Among them, the output of bio-based PE accounts for about 28% of the market share of bioplastics, and it has been successfully applied in the non-woven field. Brazil Braskem company uses 100% renewable bio-based PE and PLA as the core layer and PE as the outer layer made of Fitesa EcoFabric fiber. This fiber combines the softness of PE and the high strength of PLA, and is degradable, which is expected to become the surface fabric of medical nonwoven masks. 3. A mask with elastic material and good airtightness can effectively block foreign objects from the outside, and also effectively prevent the wearer from exhaling droplets that threaten others. Using elastic polymers as raw materials, the production of elastic non-woven fabrics for export masks can improve the fit between the mask and the face, and improve the airtightness of the mask without using the bridge of the nose, thereby avoiding medical staff from wearing the mask for a long time. Skin damage caused by the bridge of the nose. Thermoplastic polyurethane (TPU), etc. can also be used to produce elastic nonwovens. At present, elastic non-woven fabrics have been used in products such as diapers, facial masks, mask earbands, etc. If the elastic non-woven fabrics can be used to prepare masks, it is not only expected to improve the airtightness of the masks, but also to eliminate the bridge of the nose.