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Sometimes the melt-blown non-woven fabrics are not uniform due to the operating errors of the melt-blown non-woven fabric machine. We will share with you specific methods to deal with uneven meltblown non-woven fabrics.
Uneven melt-blown non-woven fabric refers to the uneven weight of the melt-blown non-woven fabric in the width direction. It can be seen from the appearance that one line is thin and one line is thick.
The reason is that the meltblown non-woven fabrics are all single-row spinnerets. If the holes are blocked in some positions, the process is abnormal, and the melt pressure is not uniform, there will be uneven weight. The following is the specific solution.
Unblock melt blockage
For reasons known, an acupuncture needle 0.2-0.25 smaller than the spinneret is used to accurately pass through the position. The melt-blown die head can adjust the air knife, by adjusting the air knife or adjusting the air volume to balance the distribution of fiber filaments.
The meltblowing die of small melt blowing equipment is generally electrically heated and is divided into several individually controlled heating units. The heating units can be adjusted separately to locally adjust the melt pressure and melt viscosity for optimization.
Adjust the uniformity of the lower ventilation to adjust the fiber spreading
The uniformity of meltblown cloth is an important basic quality index, and products with poor uniformity will lose practical value. Therefore, improving and improving the uniformity of products has always been a goal pursued by equipment manufacturers and process technicians.
The main indicators for evaluating uniformity are mass per unit area, strength, elongation, fiber fineness, and some functional indicators, such as air 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 network formation process, these differences are sampled and calculated by statistical methods.
They are usually expressed by the value of "extremely poor" and "coefficient of variation—CV". The smaller the value, the better the uniformity of the product and the isotropy. The more obvious the features, it will bring great convenience to actual use.
However, only using statistical methods to characterize the uniformity of the product may not necessarily meet the requirements of use. For example, when the product defects (such as "cloudiness" or "thin web") are uniformly distributed, the "very poor" or "CV" value Will be small, and this product is unusable. A typical example is a fishing net. Even with so many meshes, the net is very uniform.
Consider the "extreme difference range" factor of the product
In addition, in actual use, users are concerned about the "worst" state of the product, which is the control index that restricts the performance of the "manufactured product". This is like the factor that determines the amount of water in a bucket is not the longest and highest bucket plate, but the shortest one. Therefore, not only the "average value" can be used to express the uniformity of the product, but also "very poor" to express it.
"extreme difference range" is a special term in statistics, also known as "standard deviation" and "root means square deviation", which reflects the degree of deviation from the average in all measurement samples. The larger the value, the greater the deviation. The performance fluctuation range of the product is relatively wide. However, the "very poor" of products of different specifications (average value) is not comparable, and can only be judged by the size of the CV value.
If you want to know more about meltblown non-woven fabrics machines after reading the above, you can get a comprehensive solution by contacting us.
As a professional manufacturer of non-woven equipment, we have won praise and trust from many customers with our excellent technology and high-quality products. We put the needs of our customers first, the equipment we produce meets strict standards, and we also have a professional quality inspection system to strictly control the weight of each link of production. If you are interested in our meltblown non-woven equipment, please contact us immediately!