The guide layer of baby diapers can temporarily store and diffuse the liquid, so that the liquid can be absorbed by SAP slowly and evenly. This requires that the layer has good liquid absorption capacity and can absorb a large amount of liquid. Therefore, the following influencing factors should be paid attention to in the process of structural design.
Different from nonwovens produced by other processes, the irregular pores between fibers of hot air materials are large, which can accommodate several times or even dozens of times the weight. If the pores between fibers are large, more liquid can be accommodated, and less liquid with smaller pores. It can be analyzed that hot air nonwovens with the same surface density absorb more liquid than those with high density and solid plate.
Therefore, hot air nonwovens with the same surface density have larger gap and can absorb more liquid than nonwovens made of fine fibers. The study found that the fiber fineness used in the diversion layer materials of several major brands of baby diapers in the market is mostly about 6 denier.
The influence of fiber length on the material of diversion layer is mainly reflected in the guidance of liquid. The long fiber and the directional structure to be discussed later work together to guide the liquid to diffuse longitudinally along the material of the diversion layer and play the role of diversion. Therefore, the longer the fiber length, the more conducive it is to the longitudinal diffusion of the fiber guided liquid, but the longer the fiber length is, which is not conducive to the carding process in the hot air process. At present, most of the manufacturers of this layer of material adopt the fiber length of baby diapers about mm.
The fiber raw materials for the production of diversion layer materials are mostly chemical fibers. The chemical fibers themselves generally do not absorb water. Surfactants must be added to the fiber surface to reduce the contact angle e of the fibers and accelerate the absorption and diffusion of urine. At the same time, the added surfactant is also required to have good lasting hydrophilicity and weak liquid holding capacity, so that the material can be shunted for many times.
The structural stability of diversion layer material, especially the influence of wet structural stability on its performance is also very important. Under pressure, the wet material is easy to flatten, which is not conducive to the liquid absorption and conductivity of the material. Therefore, the fiber raw materials used in the material must have high modulus, the material can resist external pressure and maintain the structural stability of the material. The data show that some materials are made of hollow fiber, and the structure stability of the diversion layer material is good.
Through the above introduction, we can see that among the main factors affecting baby diapers, fiber is one of the important factors. This just gives us a little inspiration. In the production process, the fiber materials need to be tested to judge whether they are applicable, so as to ensure the full performance of baby diapers.