Medical masks and protective masks are made of non-woven materials, which are made of directional or random fibers. They are generally of multi-layer structure, usually referred to as SMS structure (2-layer s and 1-layer m). At present, the highest number of layers in China is 5, namely smmms (2-layer s and 3-layer m). S refers to spunbond, m refers to barrier layer or melt blown layer m (meltblow), all of which are composed of polypropylene (PP). The m layer uses melt blown nonwovens as the filter layer, because its fibers are randomly distributed and have complex three-dimensional porosity, the biggest characteristic is that it is composed of superfine fibers, the specific surface area of the fibers is large, and the adsorption capacity of particles is strong; The fibers of melt blown filter material are randomly distributed, forming a large number of micro pores, and the pores are evenly distributed, with small filtration resistance and high filtration efficiency, which makes the filtration performance of nonwoven medical protective mask much better than that of traditional gauze mask.
SMS non-woven fabric takes polypropylene PP (with natural bacteriostasis and hydrophobicity) as the main raw material, and the fiber diameter can reach 0.5-10um. These ultra-fine fibers with unique capillary structure increase the number of fibers per unit area and surface area, so that the melt blown fabric has good air filtration, which is a relatively good mask material. So the laser marking surface is S-layer polypropylene non-woven fabric.