There are many factors that affect the quality grade of melt-blown non-woven fabrics
From raw materials to equipment
Every process is crucial
Even if there are only individual differences
The quality of the final product may also vary greatly
After Rize's in-depth research and repeated testing
Meltblown non-woven fabric reaches N95 +
Must strictly control the following eight aspects
Now talk with everyone carefully
First, melt blown material
1. With low odor, low ash content, high isotacticity and narrow molecular weight distribution.
2. Higher fluidity.
3. Excellent fiber forming performance, can make fiber elongation higher and wire diameter smaller.
4. Continuous spinning and dripping, the spinnability is better.
5. Easy to use, more stable processing performance.
6. It can be applied to the production of melt-blown technology for filtering materials, oil-absorbing cotton, clothing accessories, battery separators and other applications.
Second, how to make meltblown cloth
1. To make the cloth well, the fibers must be made fine. The raw material melting index rate and the spinneret hole diameter are matched to optimize the spinning process. The fiber reaches 0.3um.
2. Match good electret equipment and select excellent electret masterbatch. A good electret masterbatch must have the ability to store charge and permanently generate an electric field.
3. The effective period of the mask electret depends mainly on the content of the electret masterbatch. The electret masterbatch is similar to a battery, and the addition ratio will determine its service life and adsorption capacity.
4. Store the prepared melt-blown cloth in dry place and avoid contact with outside air humidity. Vacuum packaging is best. The moisture in the air and the charge of the meltblown briquettes will be converted into negative ions, and the loss of charge will affect the filtration efficiency.
Third, the reasons for melt-blown cloth failing to meet the standard
1. Spinneret and meltblown equipment
2. Electrostatic electret equipment
3. Long-acting electrostatic electret masterbatch
4. Melt blown material or high melt fiber material
5. Professional and experienced machine debugger
6. On-site management of meltblown production
Fourth, how to choose melt-blown material
1. Melt index: polypropylene thermal degradation by adding peroxide or metallocene hydrogen adjustment method, etc. The polypropylene melt index reaches a suitably high level and can produce nano-scale fibers.
2. The particle melting point should be reduced to 150-170 ° C.
3. After the electret masterbatch is added, the melt-blown cloth passes through the electret device to produce electrostatic adsorption performance to block viruses.
4. After the polypropylene particles are modified, the fibers ejected by the melt blown cloth machine at high temperature and high pressure are fine and long.
5. The fluid fiber from the melt nozzle is soft, tough and firm.
6. High temperature sterilization and disinfection.
V. Electret masterbatch selection
1. Whether the static load time can be charged for a long time for 1 year or more.
2. The electret masterbatch does not block the meltblown holes, and the meltblown cloth carries electrical charge. How can the positive charge last for a long time on the meltblown cloth? It can be used for half a year or a year without losing charge. Key indicators of pellets and electret processes.
3. The plugging cycle is long, and the long-term electret, PFE exceeds 95.
VI. Electret process
1. Most of the mainstream applications are the corona charging method for electret treatment of meltblown cloth. The charging voltage, charging time, charging distance and environmental humidity all have an effect on the effect of electret treatment. Among them, the charging voltage has the most obvious influence on the electret effect, the charging distance has a medium influence, and the charging time has the smallest influence. Pay attention when commissioning the machine.
2. Ambient humidity has an effect on the generation and loss of static electricity. Melt-blown fabric manufacturers should always monitor the temperature and humidity in the workshop. Add corresponding equipment to keep the temperature and humidity of the workshop within a certain range.
Seven, melt-blown material
1. When melt-blown polypropylene stays at high temperature and high pressure for a long time, it is easy to sinter and carbonize.
2. The temperature must first be determined when the machine is adjusted, whether the actual temperature of the barrel and the mold on the melt-blown machine is consistent with the set temperature. Generally, the display temperature of the small meltblown equipment and the actual temperature will be very different.
3. Polypropylene with a melt index of 1500, if the temperature is set to 270 ℃ or more, it is a bit high.
8. Selection of meltblown equipment
1. The configuration must be complete: extruder → screen changer (filter) → metering pump → die head → distribution plate (auxiliary hot air) → spinneret → net forming device to form a melt-blown cloth.
2. The speed of the extruder, the parameters of the metering pump, the advantages and disadvantages of the die head, the temperature parameters of the hot air flow temperature, the angle of the die head, the angle of the air knife, the receiving distance of the melt-blown material, and the adsorption parameters under the netting device jointly determine the melt spray The quality of cloth.
If you have any demand for meltblown cloth, please contact me. We are a professional manufacturer of meltblown cloth.