The manufacturing process of sanitary napkins using hot melt adhesive mainly includes: substrate unwinding, hot melt adhesive coating, material lamination, forming, cutting, and packaging. The entire process is highly automated. Hot melt adhesive, as a pressure-sensitive adhesive, becomes tacky under pressure at room temperature and is used to bond the various layers of materials after heating.
The main difference between hot melt adhesive sanitary napkins and traditional sanitary napkins lies in the manufacturing process. Traditional sanitary napkins use adhesives to bond the various layers together, while hot melt adhesive sanitary napkins use hot melt adhesive. Hot melt adhesive is a polymer material composed of one or more resins, plasticizers, and stabilizers.
Substrate Unwinding: The various layers of the sanitary napkin (such as the top non-woven fabric, the distribution layer, the absorbent core, and the bottom film) are unwound from the roll and enter the production line.
Hot Melt Adhesive Coating: Solid hot melt adhesive is fed into a melting cylinder and heated to 150–180℃, melting it into a liquid state. This liquid is then transported to the coating die head through a precision control system. Different adhesive application processes are used depending on the bonding area:
Spiral spray adhesive: Used for structural adhesives (such as between the top layer and absorbent core), spraying out spiral adhesive threads to save on adhesive usage.
Fibrous spray adhesive: Irregular adhesive threads, requiring even less adhesive, suitable for wings, bottom film, etc.
Scraping or dotting adhesive: Used for localized bonding of backing adhesive, wing adhesive, etc., ensuring moderate adhesion and no residue.
To avoid the potential harm of hot melt adhesive sanitary napkins, women can choose other healthier and safer alternatives, such as organic cotton, bamboo fiber, and natural fabrics. These sanitary napkins not only do not contain harmful substances but are also more comfortable and may even have antibacterial and anti-inflammatory effects.