The structures of sanitary napkins

The structures of sanitary napkins can be divided into surface layer, absorption core, bottom layer, and each layer of material bonded with hot melt adhesive.

The surface layer is the part that comes into direct contact with the skin, and its material must be soft. The texture and indentation on the surface determine the effect of absorbing and preventing menstrual blood from seeping back.

The surface layer of spunbond nonwoven fabrics and the surface layer of cotton are the two most commonly used materials. The spunbond nonwoven fabric is designed with micropores, which can prevent menstrual blood from seeping back and give users a dry feeling. Due to the improved absorption design of cotton, the market share after 2001 gradually increased compared to the sanitary cotton surface layer of PE.

The absorption core is mainly composed of high molecular weight polymers and high molecular weight water absorption factors formed by cotton, non-woven fabrics, pulp or composite materials above, which are used to absorb the flowing menstrual blood.

The design of the side is mainly used to prevent side leakage, as it will present a certain angle with the sanitary pad body during use, making it more prone to friction. Therefore, using soft materials on the side of the sanitary pad is more favored by women.

The bottom layer of sanitary napkins is made of impermeable PE film, which can retain menstrual blood in sanitary pads. In the 1970s and 1980s, self-adhesive back glue was developed to facilitate the fixation of sanitary pads on underwear.