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How to make PFE 99% Melt blown fabric

Time:2020-04-23 Author:CHINA GWELL MACHINERY CO.,LTD.

FPE 99%

It seems that the melt blown cloth is not special, but the production process is very complicated.

 The production process can be summarized into three major links: 

first, naphtha is extracted from petroleum, then it is chemically processed into 

polypropylene, and finally it is made into cloth by melt blown technology. 

1. Selection of raw materials

Polypropylene is easy to be filamented, and it can be a very fine fiber (diameter 2-3 μm) 

with a high melt index (MFI ≥ 1500g / 10min). Although the gap of novel coronavirus 

produced is much larger than that of the new coronavirus size (about 0.1 M), 

its ability to filter viruses in the environment is still strong.

Because the virus can not exist independently, and its transmission way mainly includes 

secretion and sneezing droplets, the size of which is about 5 μm; the melt blown cloth is 

essentially a kind of fiber filter, and the droplets containing the virus will also be 

adsorbed on the surface by static electricity after they are close to the melt blown cloth, 

unable to pass through.

2. Production process

Melt blown cloth production process is mainly divided into three parts: melt extrusion, 

melt blown process and electret treatment. The flow is shown in the figure.

The production process drawing source of melt blown cloth epolymer polymer platform

The polymer particles are melted by a screw extruder and sent to the molten die assembly,

 including the polymer distribution system, die system, draft hot air pipeline channel 

and heating insulation element, and extruded by the spinneret hole of the die (Fig. a, b). 

The diameter of spinneret hole in melt blown process is much smaller than that of 

spinneret hole used in inner and outer spunbond, because the diameter of spunbond fiber

 is only one tenth of that of spunbond fiber.

3. Die structure source epolymer polymer platform

In order to achieve the required fineness, in addition to relying on smaller spinneret holes,

 it is also necessary to extrude the spinneret holes at the same time so that the melt fibers

 are drawn by the high-speed hot air flow on both sides (Fig. C). In addition, the room 

temperature air on both sides is mixed with hot air, which can make the drawn melt cool

 and solidify into shape.

4. Spinneret hole

Under the action of draft air flow, the drawn and cooled microfiber blows to the net 

curtain. There is a vacuum suction device at the bottom of the net curtain.

Last but not least, the electret treatment is very important. The emitter on the spinning

 line can make the melt blown fiber with a permanent static charge, so that the 

melt blown fabric has an additional electrostatic adsorption effect without hindering 

breathing. The non-woven fabric produced by melt blown process has 35% filtration 

performance, and the filtration performance can be increased to 95% after 

electret treatment.

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