Disposable diaper diversion layer is a special non-woven material, which is located between the surface layer and the absorbent core. Its main function is to temporarily store the liquid, so that the liquid can be diffused longitudinally along the diversion layer, and the absorption capacity of the absorbent core layer can be fully exerted.

Domestic disposable diaper diversion layer

In China, there are few studies on the abutment layer, and there is almost no relevant literature in China, only some patents mention it. In one of the patents, the utility model develops an infant disposable diaper composed of a top film, a current-guiding layer, an absorbent core and a back film, and its materials are not described. Among the patents for fast-penetrating sanitary napkins, various improved fast-penetrating sanitary napkins are involved. There is a closed guide groove on the surface of the towel, and there is a raised area in the guide groove. A flow guiding non-woven fabric is arranged between the surface of the raised area and the wood pulp cotton layer, and a conical penetrating hole is arranged between the surface and the flow guiding non-woven fabric. In addition, the fast-penetrating baby disposable diaper patent relates to a fast-penetrating baby disposable diaper, which includes a skin-friendly layer, an absorbent layer and a lower leak-proof layer. It is characterized in that the skin-friendly layer has a cone-shaped penetrating hole, which is formed by a cone-shaped puncture and is funnel-shaped with a depth of 1~2.5mm. In another hygienic absorbent product patent, a hygienic absorbent product is disclosed wherein the flow-guiding layer is composed of hemp material.

It can be seen from the above patents that there are very few domestic related researches, and it is still in the preliminary stage, and its structure, performance and shunt principle have not been studied.

Abroad disposable diaper diversion layer

In foreign countries, the research of researchers is earlier. In 1994, elastic edge and curved thin sanitary napkins were developed with a high loft diversion layer and a plastic film overlay. In 1995, P&G applied for a patent and developed a new disposable diaper. The new disposable diaper focuses on improving the directional absorber of liquids, involving the structure between the surface and the absorbent core. At the same time, many companies, such as Kimberly, Johnson & Johnson, and Unicharm of Japan, have applied for some patents.

Between the top layer and the absorbent core layer is an infiltration layer, which can be fabric, wood pulp fiber composite or foam. This layer can quickly absorb a large amount of liquid, prevent side leakage, and prevent liquid from penetrating into human skin. In addition, there is a patent. The diversion layer consists of a cellulose mesh. Cellulosic webs are processed by air-laid and chemical bonding. The cellulose web has more binder on the surface, less binder on the lower surface, and little or no binder in the middle. This results in a high density of the upper surface fiber network and small holes, which is contrary to the traditional shunt principle, but experiments have proved that better results can be achieved.

The diversion layer generally has two layers, the upper layer is composed of chemically bonded synthetic fibers, and the lower layer is composed of chemically bonded visible, domestic diversion dimensions. The synthetic fiber layer is porous and can quickly capture liquid under pressure, the fibers, still in the initial stage, have no capillary force to allow the liquid to be absorbed by the absorbent core! Cellulosic fiber material has been used for disposable diaper years in the diversion system. The most important material is Stiff Texturized Cellulose (STCC) fiber developed by P&G. The company uses chemical modification techniques to crimp cellulose fibers almost like small springs. It allows the fibers to form a loose, low-density layer on disposable diaper that does not collapse when wet, and allows the layer to absorb trapped liquid almost completely. Unicharm Japan has developed and patented a sanitary absorbent product grade material. The new material combines a typical thermally bonded nonwoven with thermoplastic monofilaments that are arranged parallel to their length (closely packed, leaving only a little gap). After being processed by a special concave-convex embossing device, the filaments on the composite fabric form the same wave peaks and valleys in the vertical direction in the length direction. Since the depressions of the pinch points on the layer material are located on the surface of the inner absorbent core layer, it is ensured that the body fluids are dispersed and entered into the absorbent core layer more quickly. Effectively prevent the re-seepage of body fluids in the absorbent core layer.

It can be seen from the above patents that the in-depth study of the disposable diaper shunt layer abroad has also studied the structure and properties of its materials, but these studies often have intellectual property issues, which brings legal problems to the industrial application of domestic related enterprises.