How Can The Melt-blown Cloth Production Line Make More Than 95 Filtration Efficiency
May 13, 2020
If you want to achieve the best state index above 95, you need a variety of methods to achieve the goal, every detail can not be ignored. Let me summarize the experience of adjusting the relevant process parameters of several better melt-blown cloth companies.
Mechanical line speed
Number of people
Paper tube specifications
Finished product weight
Filtration rate over 95%
High-pressure hot air flow is one of the important processes in melt-blown production, because a large amount of high-temperature clean air is required in the melt-blown process, which is directly related to the filtration efficiency of the product melt-blown cloth. In this process, the air sent by the fan is heated by the heater to the specified temperature and then sent to the melt-blown die head to blow out the molten polypropylene.
1. The high-pressure hot air flow process in the melt-blown production line should pay attention to the following aspects:
1. The air required in the melt-blown cloth process is clean, and the equipment for providing the air source should be a Roots fan. The Roots fan is the most economical and stable melt-jet source equipment. Many small production lines use air compressors. Even "oil-free" air compressors, due to their special internal lubrication structure, a small amount of oil mist will be ejected with the air flow, resulting in "Shot" and odors in the melt-blown cloth. Reduce the filtration efficiency, various tests fail to meet the standard.
2. If the pressure of the roots blower is generally below 98Kpa, generally 60-80Kpa is enough. If the air compressor is used, the pressure is generally 5-8 kg. When the melt-blown cloth production line reaches the best state, the measured pressure of the die head is at 60-70KPA, obviously, the pressure of the air compressor is too high, there is no need to pursue too high pressure, the best different production lines need to be equipped with different air volume fans or air compressors, the air compressor is higher than the fan pressure, but the air volume is far It is far inferior to the fan, so the efficiency is much lower, for example, the original 55KW air compressor is replaced by a 30KW fan.
How can a meltblown cloth with a filtration efficiency of more than 95 be made:
1. Increase the hot air flow or temperature (increasing the fineness of the fiber, reducing the porosity, improving the catching ability, but the resistance increases);
2. Increase the electrostatic voltage (current) (polarized fiber, increase the electrostatic field energy of the fiber and improve its adsorption capacity);
3. Add powder or other electrets to the raw materials (improve the fiber's power receiving capacity and storage time, let the fiber carry more charge and charge time);
4. Increase the suction of the bottom of the net (increasing the density of the fiber and improving the ability to catch the fiber. The large grammage is obvious and not commonly used);
5. Properly reduce the output (under the same process, the amount of extrusion becomes smaller, the fiber becomes thinner, and the resistance increases);
6. Raise the working temperature of the die head (die tip) and other areas (melt fluidity becomes better, fibers become thinner);
7. Increase the spinning ambient temperature (fiber becomes thinner, generally when the room temperature rises, the resistance increases more obviously, and other physical indicators decrease);
8. Properly increase the amount of powder added.
Meltblown cloth production lines vary widely, with different standards, and each production line is different. Specific parameters cannot be provided here. The overall idea of the experience of the teachers is this. That machine is also played from left to right. Step by step to adjust to the best state.
Source : http://www.up-resin.com/