Super absorbent polymers

Various polymer materials serve as the core substrates for disposable absorbent hygiene products, determining key performance attributes such as absorbency, breathability, and wearer comfort. ADL commonly utilize ES bicomponent composite fibers, which are formed by combining two polymer materials and feature either sheath-core or symmetrical structures. Airthrough nonwovens produced from these fibers exhibit a point-bonded structure that is lofty, soft, and resilient; their interconnected pore structure offers excellent liquid distribution capabilities, making them widely used as ADL in sanitary napkins and diapers.   Super absorbent polymers (SAP) serve as the core absorbent material; characterized by a three-dimensional network structure and molecular chains rich in hydrophilic groups, they efficiently absorb and lock in moisture. However, as SAP absorbs water and forms a gel, it is prone to clumping and bulging; consequently, it is typically combined with fluff pulp to form the absorbent core, leveraging the pulp's wicking action to mitigate issues such as gel blocking and clumping. Breathable microporous polyolefin films serve as the backsheet material, blocking liquid water while allowing water vapor to pass through, thereby effectively alleviating the stuffiness and humidity issues associated with traditional plastic films. In terms of development trends, innovation in these polymer materials continues. Top-sheet materials are evolving toward low re-wet properties and eco-friendly functionality, while hot-air composite nonwovens and apertured films are increasingly adopted for acquisition layers. Driven by constraints on timber resources, future absorbent cores will likely reduce reliance on fluff pulp in favor of green, functional polymer fibers, moving toward fully synthetic core structures.