There are many diapers in the market, but there are four construction for baby diapers: top sheet, diversion layer, absorption core and back sheet. But the absorption core is the most important part of diaper. As the main absorption layer, it is required to be able to absorb urine rapidly, and the urine can be quickly diffused into the whole absorption core body by using diversion and wicking effect, and then the urine can be quickly absorbed and locked by SAP without reverse osmosis.
Absorption construction
According to the different composite methods of fluff pulp, the absorption core can be divided into two categories: the traditional absorption core and the new composite absorption core.
The traditional absorption core:
The traditional fluff pulp absorption core is mainly composed of coating layer, sap and fluff pulp. Sap and fluff pulp are mixed in a certain proportion to form SAP / fluff pulp absorber; the coating layer is made of toilet paper, nonwoven materials or multi-layer composite materials, in which the upper coating layer usually has the functions of water diversion and air permeability, and the lower coating layer usually has the functions of anti-seepage and barrier.
After the traditional nappies absorb urine, fluff pulp diffuses and conducts urine by virtue of its natural fiber advantages, and SAP can quickly absorb, expand and lock the urine; in the absorption core, sap and fluff pulp are mixed loosely, and there is enough space inside the absorption core body for air permeability. Therefore, although the thickness of the diapers is relatively thick, the air permeability is good after suction. Fluffy pulp can play a role in fixing SAP to a certain extent. It can prevent SAP from moving and accumulating, maintain the smoothness and softness of the diaper surface. Moreover, the wicking effect of fluffy pulp can well solve the problem of gel blockage after SAP suction, weaken the phenomenon of easy dipstick after diapers, and improve the feeling of wearing comfortably. However, when wearing the diapers, the wearer should avoid large movement or overturning, which will lead to sap slip, and then cause uneven distribution. The areas with more SAP distribution will quickly absorb liquid and expand, which will hinder the urine diffusion, and eventually lead to fault and lumping, which will affect the multiple liquid absorption of diapers. In more serious cases, it will lead to tear of surface membrane, urine leakage and irritation of the wearer's skin.
The new composite absorption core:
As diapers become thinner and thinner, and people have higher requirements for liquid absorption performance, new composite absorption cores are emerging. It usually uses a coating layer to coat dust-free paper and porous fluffy nonwovens, then spreads SAP between the porous fluffy nonwovens, and then uses hot-melt adhesive to bond each layer
In the new composite absorption core body, porous fluffy nonwoven material is a hydrophilic material, and its grid structure can store and fix a large amount of sap, so that SAP can be evenly distributed. Therefore, the new composite absorption core will expand as a whole after absorbing urine, avoiding the fault and lumping after absorbing the liquid, and the diapers have good overall flatness. At the same time, because there is no fluff pulp added, the diapers with new composite absorption core become very light and thin, and the wearer's sense of weight-bearing is reduced, and the addition of SAP will correspondingly increase, and the amount of liquid absorption of diapers will increase.
With the continuous improvement of people's requirements for lightweight, breathable, liquid absorbent, sanitary and non irritating diaper products, the absorption core of diapers will develop towards the direction of functional diversification and integration, and the structure of absorption core body is constantly improved. Among them, the research on the structure of composite absorption core will bring new breakthroughs in the field of sanitary products, which is conducive to grasp the needs of consumers, develop better new products, give play to the market potential of diapers in China, improve market penetration and expand market share.