Study On The Spinnability Of Polysulfonamide Fiber

Polysulfonamide(PSA) fiber is a kind of new refractory fiber with high heat resistance, thermal stability and dimensional stability at elevated temperature. It plays an important role in aerospace domain, security and military fields and modern industry. But the fiber has high VSR(volume specific resistance) and initial modulus, instability of crimp and low friction coefficient, which create more static electricity and less cohesive force among fibers. These performances cause many troubles in the process of spinning, weaving and dyeing, and also limit the application of PSA fiber. Therefore, improving the spinnability of PSA has important implications for its universal availability.In this paper, according to the problems mentioned above, especially the problems in carding processing, the spinning processing of PSA fiber with different performances were carried out. Factors which influence the spinnability of PSA were found by comparing the performance of the fiber in the spinning processing and yarn quality, which will provide a reference to enhance the spinnability for manufacturer. The research works were focused on following aspects:1. Analyzing the influence of oil on spinnability of PSA. The properties of PSA adding new oil, SS oil and domestic oil were tested before spinning. Then the performances of fiber adding different oils were observed during spinning process. Combined with the properties of fiber and yarn quality, it was found that the spinnability of PSA adding new oil was good.2. Analyzing the influence of crimp properties on spinnability of PSA. The properties of PSA which nominal crimp percentage was5.4%,6.2%,7.1%,8.2%,9.3%were tested. Then spinning was carried out. Finally it was found that the fiber which nominal crimp percentage was8.2%and9.3%worked best in the spinning process. With the improvement of crimp properties, the spinnability of PSA had been improved under the same antistatic property.3. Analyzing the influence of the moisture regain on spinnability of PSA. Added new oil and SS oil to PSA. Then adding water to fiber which made the moisture regain of PSA was10%,12.5%,15%. It was found that the fiber adding new oil which moisture regain was10%and fiber adding SS oil which moisture regain was12.5%had a good performance during the spinning process. The moisture regain of semi-finished goods revealed that water retention of SS oil was better than new oil, while water adsorption of new oil was better than SS oil, which was good to the smooth progress of spinning.4. Analyzing the spinnability of aramid fibers. The properties of imported aramid fiber and domestic aramid fiber were tested and spinned respectively. The results showed that imported aramid fiber had good crimp properties and high cohesion force, promoting spinning process smoothly using a small blowing-carding unit, while serious problems aroused in the process of web formation using the carding machine because of large volume resistance. Domestic aramid fibers had good crimp properties, high cohesion force and low volume resistance, so the process of spinning was good.5. Analyzing the spinnability of POD. Though the crimp performance of POD was poorer than other chemical fibers, its cohesive force was higher, so the wet and yarn quality of POD was good. The spinnability of PSA can be improved by blending POD. The yarn quality was greatly improved.