Preparation Of Polyphenylene Sulifde Spunbond Fabric And Its Filter Performance

With the development of economy, the improvement of people’s life quality and theenhancement of environmental consciousness, air pollution in our country has become anurgent problem. The application of bag filter, which has a high efficiency in dust removing,can undoubtedly solve this problem. While the performance of bag filters depends largely onthe performance of filter materials. PPS with good thermal stability, chemical stability andcorrosion resistance had become the preferred media in the field of high temperature flue gasdust for withstanding a constant temperature of190℃and an instantaneous temperature over200℃influe gas environment. The filter material of PPS is mainly manufactured by theneedle punching, water jet or the composite process of them, and the spunbond process ofPPS is still in the research and development stage at present in the domestic. Compared withother processes, the spunbond process which is much simpler and more efficient will have agood development prospect. Based on the content and characteristics of this paper, a largenumber of studies have been done on the three aspects in the research.PPS has been chosen as the raw material. In order to determine the conditions of thespunbond process, a detailed study carried out by DSC、TG and MFR on PPS firstly. Theresults showed that the melting point temperature, the crystallization temperature and thedegree of crystallinity of PPS were280.8℃,236.4℃and51.4%respectively, that the meltflow rate (MFR) of PPS increased firstly then decreased, when the temperature ranged from290℃to330℃. And that the MFR at315℃reached the maximum value of158.7g/10min.The initial degradation temperature was450℃. The corresponding maximum value is0.55%/℃when the temperature reaches548℃.And then, the PPS fiber was got from spunbond nonwoven materials. The microstructure,tensile properties, condensed structure of different drawing airflow intensity PPS fibers weretested by the dynamic screen microscope, electronic tensile strength tester, sound velocityorientation instrument and differential scanning calorimeter. The results showed that thediameter of PPS fibers decreased, while the range of the tendency became small with theincrease of the drawing airflow intensity, that the breaking strength first decreased and thenincreased, that the elongation at break first increased and then decreased, that the degree oforientation first increased and then decreased, and that the degree of crystallization showed aslight increased. The results of PPS after the heat treatment tested by DSC and tensile testershowed that the degree of crystallinity and the Tgof PPS increased, that the Tmhad nosignificant changes, and that the breaking strength decreased firstly, then increased, while theelongation at break decreased dramatically.On the basis, the filter efficiency, pore size and distribution of PPS spunbond materialunder different RPM of metering pump, drawing airflow intensity and lapping speed had beentested, the results showed that with the increase of RPM of metering pump, the change in thefilter efficiency and the average size of pore had no regular pattern. With the drawing airflow intensity increasing, the filter efficiency increased, and the average pore size showed adecreasing trend. With the lapping speed increasing, the filter efficiency for particles below5μm became worse, while the filter efficiency for particles whose size is above10μm was allhigh, and the average pore size showed a tendency of increasing.