Technology - 7 common defects in melt blown cloth production and Countermeasures

- May 18, 2020-

In fact, the production of melt blown cloth is not complicated, and the problems are caused by temperature, air pressure, mold, material, speed and other factors. Therefore, it is necessary to continuously run in and debug the equipment and process to achieve the best results. Here are 7 common defects of melt blown cloth:

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1Crystal point

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Generation mechanism:

a. The air velocity is too small or the melt viscosity is too high, and some melt filaments are not fully drawn;

b. When the viscosity of the melt is too small and the air velocity is high, the holding effect of the spinneret hole on the melt is weakened, and the melt will leave the spinneret hole before it is drawn into fiber.

Solutions:

a. Raise or lower the temperature according to the melting finger of the material;

b. Adjust screw speed;

c. Select suitable die head and material of fusing finger of spinneret hole.

 

2Catkins

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Production mechanism: raw materials and corresponding spinning temperature are not well matched, resulting in high temperature.

Solutions:

a. If it is full width flying flocs, screw spinning temperature and hot air temperature can be adjusted;

b. If it is a regional flying floc, the die head temperature of the corresponding location can be adjusted.

 

3Crisp and hard cloth

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Production mechanism: the melt is not sprayed into fibrous shape or multiple fibers are agglomerated, resulting in brittle and hard melt blown cloth.

Solutions:

a. Adjust the hot air pressure;

b. Adjust die temperature;

c. Reduce the feeding quantity;

d. Adjust the distance between the roller or curtain and the spinneret.

 

4Plugging hole

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Generation mechanism: generally, hole plugging is mainly caused by too much electret masterbatch, too many inorganic components, impurities in melt blown materials and no filter screen.

Solutions:

a. Reducing the amount of electret masterbatch;

b. Add filter screen;

c. Select clean raw materials;

d. Replace the filter screen in time.

 

5Uneven spinneret

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Production mechanism: different resistance or air flow of each spinneret hole results in different spinneret quantity of each hole.

Solutions:

a. Select the precision die head and spinneret with the same pressure of each spinneret hole;

b. Replace the filter screen in time;

c. Clean the spinneret regularly;

d. Reduce the amount of electret masterbatch.

 

6Stomata

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Production mechanism: the moisture content of the material is too high, which results in air splashing and air holes.

Solution: dry the materials.

 

7Low filtration efficiency

Generation mechanism:

a. The ejected fiber is thick and the gap is large;

b. Not adding electret masterbatch or not enough;

c. No corona treatment or insufficient treatment.

Solutions:

a. Raise the temperature;

b. Adjust the receiving distance of cloth;

c. Reduce the feeding quantity;

d. Increase air pressure;

f. Increase the content of electret masterbatch;

e. Corona treatment.