At present, the structure of sanitary products is made of multi-layer non woven through composite processing, and its development has attracted close attention of enterprises and scientific research. This paper introduces the development of non woven fabric used in surface layer and diversion layer.
Wang Ya and others mixed silk staple fiber into es hot air nonwoven material, then combed the mixed fiber into a net, reinforced with Spunlaced, and made non woven for composite diaper surface. This material has good mechanical properties, air permeability, fast liquid penetration and other characteristics, and meets the requirements of sanitary products. Yuan Chuangang and others mixed lyocell and chitin fibers into es hot air nonwovens to produce nonwovens for sanitary products with high permeability and water absorption. Moreover, this material has excellent antibacterial effect. Membrane diversion has good impermeability. Thompson applied hydrophobic avant-garde to the surface layer to achieve rapid absorption by changing the number and dimension of capillaries in the membrane. P & G developed a functional surface material using coating technology to prevent feces from adhering. The material has large pore size and high opening rate, which can ensure that the user's skin remains dry for a long time. Japanese Unica company has developed an absorbent surface layer for sanitation, which arranges low-density PE filaments in parallel on the ES fiber mesh of composite structure, and obtains a three-dimensional wavy surface material by hot rolling with a roller with a pyramid cone at softening temperature, so as to improve the softness and permeability of the material and improve the conductivity of the surface material to liquid. Kao Corporation of Japan has developed a convex composite surface material. Both layers arch towards the skin to form a wavy shape. This material can further improve the softness and permeability of the product.
The development trend of the diversion layer is to increase the diversion velocity, expand the diversion area and distribute the liquid evenly. In order to improve the comprehensive performance of diversion layer materials, people have developed diversion layers with different structures.
(1) Double layer composite diversion layer. The patent us6479415b1 discloses a diversion layer with composite structure, which is made of polymer fiber and cellulose. The polymer fiber layer can quickly absorb and transport liquid, and the cellulose fiber layer can greatly reduce the reverse osmosis of the product. Patent us7204907b2 introduces a three-dimensional non woven, which can effectively improve the liquid transmission and water locking functions of sanitary products. Liu Chao et al. Designed a kind of guide layer and damping layer, which are made by alternating the regular arrangement of fibers and the irregular arrangement of fiber layers. The superposition of these two fibers can make a composite guide layer material with excellent liquid transmission performance. Shanghai Fengge non woven fabric Co., Ltd. has developed a double-layer structure of the diversion layer, including the longitudinal carding fiber layer and the transverse carding fiber layer. The longitudinal fiber layer contacts the surface layer, and the transverse fluffy fiber contacts the absorption core layer. The liquid quickly infiltrates into the absorption core, and at the same time, it will not reverse to the permeable surface, which improves the skin comfort of users to a certain extent.
(2) Perforated membrane guide layer. The guide layer contains through holes, which can improve the conduction rate of liquid, reduce the use of raw materials, and promote the development of ultra-thin products. Compared with the conventional guide layer material, the aquidry PlusTM thin film guide layer with a weight of 26g/m2 developed by Tredegar of the United States has a 25% increase in liquid transmission rate and a 30% decrease in surface humidity of the product.
At present, although the commercialized sanitary products can meet the primary needs of users, there are still some defects in the products themselves. Understanding the development of non woven in the application of sanitary products is beneficial to the further development of non woven fabric.