Two-layer masks are of poor quality. Medical masks must have three layers. Both sides of medical masks are usually spunbonded non-woven fabrics, and the middle is meltblown fabric. A good meltblown cloth is heavy enough. It looks white rather than transparent, and looks a bit like paper. The thinner the meltblown cloth, the worse the protective effect. The melt blown layer will melt when it encounters fire and will not burn. The melt blown layer has an electrostatic adsorption effect. You can use these to distinguish true from false.

Everyone cuts a regular medical surgical mask and you can see that this mask has a three-layer structure, namely SMS structure:

1. The inner S layer is ordinary non-woven fabric, which is mainly hygroscopic;

2. The outer S layer is a non-woven fabric with waterproof treatment, which is mainly used to isolate the liquid sprayed by the patient and have the effect of preventing droplets.

3. The middle M layer uses an electret treated melt blown cloth, which can filter suspended bacterial particles and is the most important core layer. Melt blown cloth is a kind of polypropylene with high melt index as a material, a film made of many criss-cross fibers stacked in random directions. The fiber diameter ranges from 0.5 to 10 microns, and the fiber diameter is about 30 minutes of the hair. one. An ordinary medical mask needs about 1g meltblown cloth + 2g spunbond cloth; an N95 mask needs about 3-4g meltblown cloth + 4g spunbond cloth.