Panty-shape diapers exist mainly because they can absorb urine and keep the surface in contact with the skin dry and comfortable. The premise of achieving this condition is that when urine is generated, it can diffuse outward from the surface layer. The main thing is to do a good job in the analysis of liquid permeability in order to better complete this function.
Experimental steps: make a small sample of the material, attach it to the surface of the slide flatly, and put it into the contact angle instrument to measure the hydrophobic contact angle.
The four products are hydrophobic materials, and the hydrophobic angle is greater than 130 °. The main reason is that these three fiber raw materials: ordinary polyester fiber, super cotton like polyester fiber and ES fiber are hydrophobic fibers. Although there is nylon 66 in super Imitation cotton fiber, the grafting content is very low. The overall performance of the fiber is hydrophobic fiber. However, it can be seen from the results that the hydrophobic angle of super Imitation cotton polyester spunlaced nonwovens is the smallest, that is, among the four products, its hydrophilic effect is the best. To sum up, these four materials do not meet the rapid penetration characteristics required for the surface of panty-shape diapers, so hydrophilic finishing is required.
The hydrophilic finishing scheme is mainly realized by changing the solubility of hydrophilic agent. After hydrophilic finishing, the appropriate hydrophilic scheme was selected by observing the distribution and molding of finishing agent, hydrophilic effect of material, oiling rate, liquid penetration time and reverse osmosis under electron microscope.
It can be seen from the electron microscope photos that the hydrophilic agent not only forms a membrane structure between the fibers, but also covers the surface of the fibers to form a hydrophilic agent covering film. This form of fiber surface can be regarded as the modification treatment of fiber, which makes the fiber from hydrophobic fiber to hydrophilic fiber, so as to greatly improve the hydrophilic effect of the material. Some hydrophilic agents only cover the winding nodes of the fiber and solidify, so as to improve the strength.
With the increase of the solubility of hydrophilic agent, the oiling rate of the material gradually increases. When the solubility of hydrophilic agent is greater than 4%, the oiling rate of the material is very high, some of which reach more than 50%, which greatly improves the surface density of the material. For the panty-shape diaper layer material, the large oiling rate is not conducive to the mild of the panty-shape diaper layer material. It can be seen from the graph that the oil consumption rate of ES hot air material is lower than that of super Imitation cotton Spunlaced material, mainly due to the fluffy structure of ES hot air material, and the hydrophilic agent is difficult to form the surface film structure in the material, most of which is covered with fiber membrane. In contrast, the hydrophilic agent adheres less and reduces the oiling rate.
In addition to the above tests, there are other relevant liquid permeability analysis. And the test methods of different manufacturers will be different according to the performance parameters required by panty-shape diapers, and the methods and standards will also be different. But even if the tests are different, the idea of making a perfect product is common.