Many friends say that under the same processing conditions, the thickness of non-woven fabrics is uneven during production. So what are the reasons? We specifically summarize the following points:
1. The blending of low melting point fibers and conventional fibers is not uniform
Since different fibers have different cohesion, in general, low-melting fibers have greater cohesion than conventional fibers. If the low-melting fibers are not uniformly dispersed, the part with less content cannot be formed in time. With enough network structure, the non-woven fabric produced in this way is thinner, which is thicker than the place where the content of low-melting fiber is more.
2. Incomplete melting of low melting point fibers
This situation is mainly due to insufficient temperature. For non-woven fabrics with low basis weight, the problem of insufficient temperature is not easy to occur, but special attention is required for products with high basis weight and high thickness. Because the non-woven fabric on the side has enough heat, it is usually thicker, and the non-woven fabric in the middle part forms a thinner non-woven fabric because the heat is easy to be insufficient, which is one of the reasons.
3. The shrinkage rate of the fiber is high
Regardless of whether it is a conventional fiber or a low-melting fiber, if the hot air shrinkage rate of the fiber is high, uneven thickness will also occur during the production of non-woven fabrics.
1. External factors may be because the weather is too dry and the humidity is not enough.
2. When there is no antistatic agent on the fiber, because the moisture regain of polyester cotton is 0.3%, the result of the lack of antistatic agent will easily generate static electricity during the production of non-woven fabrics.
3. The oil content of the fiber is low, and the relative content of the static agent will also generate static electricity.
4. The method of preventing static electricity In addition to humidifying the production workshop, it is also a very important job to effectively remove oil-free cotton in the cotton feeding stage.
1. Due to the uneven blending of low-melting fiber and conventional fiber, the part with high low-melting point content is harder, and conversely, the part with lower content is softer.
2. In addition, the incomplete melting of low-melting fibers can easily lead to the appearance of soft non-woven fabrics.
3. The high shrinkage rate of the fiber will also cause the problem of uneven hardness and softness of the non-woven fabric.
The above is about the reasons for the uneven hardness and softness of non-woven fabrics in the production process. It seems that there are still many reasons to pay attention to the production process to improve the production quality.