The reasons include: the viscosity of the melt is too high, the spinneret hole does not have enough grip on the melt, there is moisture in the raw material, and the nozzle is dirty.
Meltblown cloth is an important raw material for the production of masks. When masks are in short supply, a large amount of capital pours into the meltblown cloth production industry. Because it is a cross-industry operation and is not familiar with the production process of meltblown cloth, the produced meltblown cloth has Crystallization does not meet the requirements. What is the problem with crystallization of melt blown cloth? Let’s go through it together below.
The hot air velocity is too low, or the melt viscosity is too high, the fluidity is low, and some of the filaments are not fully drawn, resulting in lumps.
Hot gas flow rate is too high, or melt viscosity is too low, spinneret hole on the melt grip force is not enough, not fully drawn into wire will be separated from the hole, forming a bulk crystal point (the main factor) .
There is moisture, including moisture in raw materials, and high moisture in the air compressor so that the air flow has moisture will cause crystal points.
The nozzle is dirty, there are sundries, and it is blocked, resulting in poor spinneret, and there are too many crystal points locally. The nozzle needs to be cleaned. Pay attention to whether there is abnormal shutdown, and whether the temperature reaches the set temperature when starting up.
The temperature of the hot air flow has a great influence on the viscosity of the melt. When the temperature is too high, it is easy to form folds and flying flowers on the surface of the cloth. When the temperature is too low, the silk is not fine enough, and the cloth feels hard and soft enough.
Generally, the most effective way is to clean the melt-blown die head and air knife by scraper. It is more difficult to dredge the spinneret hole, and the risk is also higher. There are also some small particles due to a grout leak somewhere in the spinneret, which is coming down from Didi bit by bit. It could be another oil spill. Then from the process to adjust, reduce the die temperature, reduce the hot air temperature, reduce the drafting force, the general effect is not good, it is necessary to remove the board, replace the spinneret. Cleanliness requirements are required when replacing the spinneret, and the die head should also be drained clean.