1 Production Process and Equipment
1.1 Flux process
production processes include, but are not limited to: melt preparation (raw material delivery, melt extrusion), filtration, metering, melt extrusion from spinneret holes, melt flow drafting and cooling, netting, winding cutting and inspection packaging, etc.
1.2 Main equipment for melt-blown equipment
Including feeding machine, screw extruder, metering pump, melt-blown die assembly, air compressor, air heater, receiving device, winding device, etc.
1.3 Main Control Process
1.3.1 Melt preparation (feed delivery, melt extrusion)
Screw extruder was used to melt the raw material and press the melt.
1.3.2 Filter
before the melt enters the spinneret, it should be filtered to remove impurities and residual catalysts after polymerization.
1.3.3 Measurement
Before the melt enters the spinneret, the gear metering pump should be used to accurately measure the melt to accurately control the fiber fineness and the uniformity of the nonwovens by melt spraying.
1.3.4 Melting, cooling
the melt enters from the inlet zone of the spinneret, it should be ensured that the melt flows uniformly in the whole spinneret length direction and has a uniform retention time to accurately control its uniformity throughout the width. The melt is extruded from the spinneret through the pore-flow region and the puffed region, and the melt fine flow is formed, and the ultrafine fiber is formed by air cooling at room temperature. The size of the spinneret should be moderate.
1.3.5 Net
after drafting and cooling the cured microfiber under the action of draft air flow, blowing to the mesh forming machine, the mesh forming machine should be equipped with a suction device, the microfiber is collected on the mesh forming machine, and the melt-blown nonwoven fabric is formed by its own thermal bonding.
1.3.6 electret process
By means of electret, water electret or friction charge, the melt-blown nonwoven fabric is charged. the electret process can be set according to the actual production.
2 Main Process Control
2.1 Raw material quality
polypropylene melting index, isotacticity, etc.
2.2 Process parameters
2.2.1 online parameters
melt extrusion volume, melt temperature, tensile hot air temperature and flow rate, receiving distance, etc.
2.2.2 offline parameters
spinneret hole shape, stretch hot air channel size, angle, etc.