After years of development, the function of baby diapers has become more and more perfect, whether it is the basic performance of products such as basic liquid absorption ability and shunting ability, or even the comfort of products. The market is still expanding, so many enterprises are still ready to participate. But before joining, we must do basic homework well. Therefore, this paper will start with the structure of baby diapers and briefly introduce the performance of its surface.
Modern baby diapers are liquid absorption control systems made of multi-layer nonwovens. According to the structure, it is mainly composed of surface coating, absorption core layer and bottom film. Its working principle is: firstly, it receives urine from the product surface, and then infiltrates downward. Then, these infiltrated urine will be received by the guide layer, and then conduct and diffuse longitudinally through the channel of the guide layer. Fluff pulp rapidly absorbs and diffuses liquid through capillary action. Then, the liquid in the pulp fiber is absorbed by SAP (super absorbent polymer), and the pulp returns to the dry state. SAP forms colloid after absorbing urine. Even if it is pressurized by external force, it can lock the liquid and prevent it from being extruded. The overall performance of the product is closely related to the structure of each layer. The excellent absorption core layer is also inseparable from the excellent surface layer and diversion layer. The structure of each layer interacts and plays the greatest role.
At present, the market has new demands for the functionality, comfort, safety, environmental protection, lightness and personalization of baby diapers. Technological innovation, market growth and consumption upgrading will be the main driving force for the development of baby diaper industry.
The main function of the surface material is to quickly transfer urine or other liquids to the next layer of the baby's diapers. In the process of use, it is not only necessary to directly contact the baby's delicate skin, but also ensure that the surface is relatively dry and soft, and allow the liquid to pass through. The surface layer of baby diapers is the first link to realize its function and the beginning of the whole liquid absorption process. Therefore, the advantages and disadvantages of various performance indexes of materials are very worthy of attention. The function of this layer emphasizes water conduction, quick drying, moisture permeability, etc., so the common test indicators mainly include penetration time, back seepage, sliding seepage, etc.
Penetration time is one of the most important indicators to measure the surface material, which reflects whether the material surface can quickly make the liquid diffuse evenly along the surface and transfer the liquid to the absorption core layer in time, rather than the penetration time of weaving material is related to its own structure. From the molecular point of view, the principle of water permeability mainly has three forms: the direct absorption of water molecules by fibers, the capillary and water compression between fibers make water molecules pass through the fabric gap. As the surface layer needs to be kept dry, hydrophobic fibers with low moisture absorption are usually selected, that is, the first water permeability method is excluded, and the second and third methods are the main water permeability methods of materials.
I believe that according to the above description, we have a general understanding of baby diapers. Since the surface layer is in direct contact with the skin, it is necessary to protect the skin from bacteria. Therefore, we should pay attention to its role in the whole structure, so as to transition to the diversion layer.