In the production process of meltblown nonwoven, because of the parameters of temperature, air pressure, mold, speed and other aspects of the ratio, so the need for constant running in and debugging, in order to make the product to achieve the best results. The following is the experience summarized in the actual production process for your reference:
One: Machine adjustment process
1. Make the cloth softer under higher temperature and wind pressure;
2. Slowly reduce the die head temperature and the hot air temperature in turn until the cloth looks a little hard;
3. Record the die head temperature and screw temperature at this time;
4. Adjust the wind pressure, melt extrusion amount and net distance to make the cloth more soft;
5. Adjust the winding speed to achieve full traction;
6, standing-pole according to the speed of the grid, generally add two standing-poles can, static voltage in 40KV-60kV, standing-pole bar distance 5-7 cm cloth surface, slowly add a static electricity can be, you can choose to add positive, you can choose to add negative, can be determined by the test.
Two: Adjust the starting parameter setting
1. Screw temperature: set 190 ° C, 230 ° C, 230 ° C…, 230 degrees, 270 degrees (1500 melt material does not exceed 270 degrees, can be 260 degrees);
2, die temperature: 252 degrees, 252 degrees…, 252 degrees (generally 240 degrees -255 degrees);
3. Quick screen changer, metering pump, die head filter: 240 degrees;
4. Heating pot temperature: 300 degrees, hot air temperature: 240 degrees;
5, wind pressure: 0.2-0.5mpa (general low temperature PP material, the wind pressure can be selected a little smaller, medium temperature material, melting point about 1300 material wind pressure can be a little larger);
6. Netting distance: 15-19 cm;
7. The size of the tuyere is consistent with the distance from the spinneret tip to the plane of the wind knife, 1-2mm;
8, screw rotation speed is moderate or small (small wind pressure, extrusion volume can be small, large wind pressure, extrusion volume can be large).
Three: adjust the abnormal situation processing
1. If the cloth is still not soft at the recommended high temperature, there may be a problem with the temperature induction or temperature control, directly continue to increase the temperature until the cloth is in a soft state;
2. If the air pressure is below 0.2mpa and the die head temperature is around or below 210 degrees, there will be the phenomenon of flying flowers. It is possible that the melting spray PP melting point is abnormal, or the temperature induction is abnormal, the air pressure display is abnormal, or the air duct outlet size and Angle is abnormal, so the equipment manufacturer or raw material manufacturer should be contacted to eliminate the abnormality;
3. It is recommended to use low-temperature materials for large equipment and medium-high temperature materials for small equipment;
4. Generally, if the cloth is not soft when it is added to a high temperature, or it starts to become brittle, and then the temperature is further increased, the cloth begins to become soft. Generally speaking, there is a problem with the equipment itself, so it is suggested to contact the equipment manufacturer, or there is a serious quality problem with the material;
5. The addition of electret masterbatches generally needs to be matched by adjusting appropriate process parameters. Different electret masterbatches have different corresponding process parameters, which can be adjusted to the best state according to this rapid adjustment process, and then compared with the performance;
6. The larger the amount of electret masterbatch is, the better the electrostatic effect will be. However, the greater the influence on the cloth will be, so it is necessary to achieve balance, and the premise is to make the cloth well.
Four: Application Case (Temperature setting)
1, screw temperature: 190 degrees, 230 degrees, 230 degrees…, 230 degrees, 260 degrees;
2. Die temperature: 240 degrees, 240 degrees…240 degrees;
3. Quick screen changer, metering pump, die head filter: 245 °;
4. Heating pot temperature: 300 degrees, hot air temperature: 220 degrees.
The fiber is easy to be oxidized in the air, especially at high temperature, so in general, the mold head temperature and hot air temperature need to be lower, the screw temperature needs to be higher, at the same time, the filtering position, the temperature needs to be higher, so as to reduce the frequency of plugging mold head.
Five: An explanation of electrostatic attenuation
In order to improve the efficiency of air filtration, electret treatment and the addition of electret masterbatch are also needed to improve the electrostatic adsorption capacity and filter the submicroparticles in the gas carrier more effectively.
1. melt-blown fabric after processing by in, except in very masterbatch can take electrostatic, melt-blown PP material can also bring electrostatic, add small amounts in extremely masterbatch on the belt of the filter effect of the electrostatic contribution in general is about 10-20%, and the electrostatic is relatively stable, under appropriate storage conditions, the attenuation is slow, and melt-blown PP material also can bring a lot of static electricity, can be very large contribution to the filtering effect of improved, but also decay quickly;
2. The decrease of filtration efficiency is not the same as the electrostatic attenuation of electret mastermind, but the electrostatic attenuation of molten shotcrete PP may make the filtration efficiency decrease rapidly;
3. The cloth made at high die head temperature and hot air temperature looks soft, but its toughness is insufficient. With the extension of time, the cloth will become brittle and lead to the decrease of filtering effect;
Six: filter effect improvement debugging method
1, if you want to make a filter effect the stability of the cloth, first of all, in does not add in extremely masterbatch and processing conditions, the demands of melt-blown filter cloth fundamental physics effect more, on the basis of this, you can join in a masterbatch, do not add in processing, testing the filter effect of the differences, good in extremely masterbatch do not add in, still can be generated through the winding process of static electricity, so as to improve the filter effect of melt-blown cloth;
2. Generally speaking, the basic physical filtration efficiency of melt spraying cloth needs to reach 60%-80%, and then stable filtration efficiency can be achieved through the addition of electret masterbatch and electret treatment.
The above is about: melt blown nonwoven fabric rapid adjustment method, I hope to have some help to you; We are a meltblown nonwoven factory, welcome to consult.