Hot melt adhesive, as an adhesive in disposable sanitary products, plays an important role. This paper briefly introduces the main components and types of hot melt pressure sensitive adhesive.
Hot melt adhesive, because it will produce viscosity under pressure at room temperature, its full name is hot melt pressure sensitive adhesive. Its main components are styrene butadiene styrene or styrene isoprene styrene rubber, tackifying resin (mainly petroleum resin), white mineral oil, etc. Because its manufacturing and use environment is generally high temperature of 130-170 ℃, antioxidants must also be added. Glues in different stations have different use requirements and process characteristics, so it is necessary to constantly adjust the proportion of various components in the formula and focus on products in different directions.
In disposable sanitary products, the position of hot melt adhesive coating is almost distributed on each layer of materials. According to the classification of function, it can be mainly divided into positioning glue, structural glue and rubber band glue.
(1) Positioning glue, as the name suggests, mainly plays the role of fixing products. At present, it is mainly coated on the bottom film of female sanitary napkins and wrapped with release paper. When using the sanitary napkin, tear off the release paper, and the exposed positioning glue can fix the body and wings of the sanitary napkin on the underwear. Since the positioning glue should not only fix the sanitary napkin, but also ensure that there are no glue marks on the underwear, the focus of the positioning glue is to have moderate bonding strength and good cohesion strength.
(2) The function of structural adhesive is to bond various materials into shape, and the coverage is the widest among disposable sanitary products. Moreover, structural adhesive itself will not be coated on the outside of materials, so the focus of structural adhesive is excellent bonding strength.
(3) The function of rubber band glue is to glue the elastic materials in diapers or high-grade sanitary napkins together, such as the rubber band of the guard or leg, etc. These elastic materials ensure that disposable sanitary products are more close to the body, and there will be no side leakage when receiving urine. Because these elastic materials are generally bonded after straightening in the production process, the rubber band adhesive must bear the retraction force of the elastic material after coating to ensure that the material will not detach from the adhesive layer, resulting in product deformation. Therefore, the focus of rubber band glue is excellent creep resistance.
Hot melt adhesive is widely used in the bonding of disposable sanitary products because of its environmental protection, safety, high bonding strength, suitable for automated production and other advantages. Understanding the main components and types of hot melt pressure sensitive adhesive is conducive to the better use of this material.