With the maturity of the composite absorbent core technology, more and more pull-on manufacturers are using the core layer. It is an important component in determining the performance of pull-on products and is the core of the entire product. Only a reasonable design can ensure that it absorbs liquid well and is not too bulky itself.
pull-ups The composite absorption core layer is composed of three layers of non-woven materials. According to the multi-layer gradient structure designed above, the fiber composition of each layer of material is determined as follows: the first layer: ES fiber and viscose fiber; the second layer: SAF fiber and viscose; third layer: viscose SAF fiber. Wherein, the SAF fiber content in the material of the third layer is greater than that of the second layer.
SAF fibers mainly play the role of liquid absorption and retention. According to the raw materials and production methods, it can be divided into four categories: polyacrylonitrile, polycarboxylic acid, modified cellulose and modified polyvinyl alcohol. Polyacrylate SAF fiber is currently the most widely used due to its fast liquid absorption, non-toxicity, high temperature resistance and moderate cost. Compared with cellulose superabsorbent fiber, it has the advantages of good liquid retention and high gel strength; compared with polyvinyl alcohol superabsorbent fiber, it has the advantage of strong water absorption, so this superabsorbent fiber is used in the largest amount .
Since the SAF fiber will become a gel state after absorbing liquid, in order to make the gel have a certain three-dimensional structure, the main reason why the binder fiber is selected as the skeleton support material in the composite absorbent core to be mixed into the SAF fiber is that it has its own Absorbent. In addition, the binder fiber can not only use its own hygroscopic properties to provide a certain buffer space for the material during the liquid absorption process of the nonwoven material, but also connect and mix the SAF/bonded hybrid fiber structure, which is beneficial to the physical and mechanical properties of the nonwoven material. stable and hygroscopic post-molding. At the same time, the binder fibers can also use the capillary phenomenon to help the liquid spread to other parts.
ES (PE/PP) fiber is mainly used as the hot melt fiber in the first layer material, the core layer is PP, which plays the role of the main fiber, and the shell layer is PE, which plays the role of hot melt bonding. In the process of hot melt bonding, PE melted and flowed as the ES fiber shell component, and after cooling, a point-bonded structure was formed at the fiber intersections, while PP as the core component maintained its original characteristics. The point-like bonding structure formed by ES fiber by hot melt bonding is beneficial to make the non-woven material have the advantages of fluffy, good elasticity, good air permeability and high strength.
Pull-up pants composite absorbent core layer throughout the product, so the quality of the material should be strictly controlled so as not to affect the entire product due to partial problems.