What are the factors that affect the uniformity of non-woven fabrics?

The uniformity of the product is an important basic quality index of the non-woven fabric(Spunbond Polypropylene Fabric Factory), and the product with poor uniformity will lose its practical value. Therefore, improving and improving the uniformity of products has always been the goal pursued by equipment manufacturers and process technicians.

The indicators for assessing uniformity are: mass per unit area, strength, elongation, fiber fineness and some functional indicators, such as gas permeability, barrier properties, liquid permeability, antistatic properties, etc.

The uniformity of the mass distribution of the web reflects the difference or dispersion of the area density (g/m2) at different locations. Due to the randomness of the non-woven fabric(PP Non Woven Fabric Supplier) forming process, these differences are statistically sampled and calculated. The commonly used "very poor" and "variation coefficient - CV" values ​​are expressed. The smaller the value, the better the uniformity of the product. The more obvious the characteristics of isotropic, the greater convenience will be brought to practical use.

However, only statistical methods to characterize the uniformity of the product may not meet the requirements of use. For example, when the defects of the product (such as "cloud spot" or "thin net") are evenly distributed, the "very poor" or "CV" value It will be small and this product(Polypropylene Non Woven Fabric Company) will not be available. A typical example is a fishing net, even though there are so many meshes, the net is very uniform.

In addition, in actual use, the user is concerned with the "worst" state of the product, which is the control indicator that restricts the performance of the "finished product". This is like determining the amount of water in a bucket is not the longest, highest barrel, but the shortest one. Therefore, it is not possible to use only the "average value" to indicate the uniformity of the product, but also to use "extremely poor".

“Very bad” is a special term for statistics, also called “standard deviation” and “root mean square difference”, which reflects the degree of deviation from the average value in all measurement samples. The larger the value, the larger the deviation. The performance fluctuation range of the product is wider. However, the "very poor" of different specifications (average) products are not comparable, and can only be judged by the size of the CV value.