The continuous improvement of the utilization rate of baby nappys has brought about the continuous addition of new enterprises. However, if enterprises want to gain a foothold in this market, it is obviously not enough to rely on marketing means alone. The iron still needs to be hard, and the key is whether the performance of baby nappy products is competitive. Therefore, some tests are inevitable in the process of product design.
A certain pressure difference is applied on both sides of the material. Under the action of the pressure difference, the air changes from high pressure to low pressure. This is the process of measuring air permeability by constant pressure test.
With the increase of surface density, the permeability of the material decreases continuously. The main reason for this change trend is that with the increase of surface density and material thickness, the resistance of air from high pressure to low pressure increases, and the permeability of the final material decreases. Under the same surface density, the air permeability of ES hot air nonwovens is much higher than that of super Imitation cotton polyester spunlaced nonwovens, mainly because the structure of hot air nonwovens is too fluffy and the gap is large, which reduces the resistance of air passing through the material. Under the same surface density, the permeability of high water needle energy Spunlaced material is worse than that of low water needle energy Spunlaced material, mainly because under the same conditions, the higher the water needle energy, the better the entanglement effect between fibers, and the smaller and tighter the fiber gap.
Experimental steps: firstly, put the sample into the constant temperature and pressure chamber for pre conditioning; Secondly, cut the sample to avoid unnecessary mass loss; Finally, install the sample, install the abrasive, test and evaluate.
It can be found that after some materials are wear-resistant, there are a large number of balls in the center of the material, which can be regarded as wool balls between fibers; Most super Imitation cotton spunlaced nonwovens have no hair or slight hair on the material surface after friction, which belongs to qualified products. A large number of super Imitation cotton spunlaced nonwovens with serious and very serious fuzzing are summarized. It is found that when the surface density is less than 35 / m2, the pilling phenomenon of the material is more serious or serious. The main reason is that in the process of spunlacing, in order to reduce the damage to the fiber net, less spunlacing channels and lower spunlacing pressure are generally adopted, so that the entanglement between fibers is not as close as that of high gram weight materials, which is easy to break away from the bondage between fibers, slide and finally pilling.
Test principle of PMI pore size meter: the principle of bubble point method to test the pore size characteristics of fiber filter material is: the wetting agent with known surface tension is fully soaked and put into the sample chamber, and the gas is analyzed and calculated through the dry and wet holes of the sample under pressure.
With the increase of material surface density, the pore diameter of super Imitation cotton spunlaced nonwovens first decreases. When the surface density of the material is greater than 50g / m2, the average pore diameter of the material fluctuates, but remains within a certain range, which can be regarded as no change; Es hot air nonwovens have fluffy structure, large gap and many pore diameters. The average pore diameter of ES hot air nonwovens changes little with the surface density and remains between 120-150um. It is not difficult to find that the average pore diameter of ES hot air nonwovens is more than twice that of super Imitation cotton polyester materials, which can be described as porous and large pore diameter materials.
The performance and comfort of nappys will be affected by different materials. Therefore, in the testing process, we should focus on the purpose of product design.