The Development And Technology Research On Blended Yarn Of Retardant Polyimide Fibre

Polyimide fiber is widely used in aerospace and industrial production for itsstable and excellent performance.However, as an expensive high-performance fibers,Polyimide fiber has few applications in the field of clothing. The thesis focuses on thesubject of Polyimide fiber, which starting from and give attention to two or morethings of the flame retardant properties and wear-comfort.Studying its blendingprocess with flame retardant viscose fiber which the economic costs of products andfiber spinnability are take into account.Spinning seven kinds of blended yarns withdifferent proportions, then knitting into underwear fabric with flame retardantperformance respectively. The system research and analysis on the performance of theyarn and fabric have done. Selecting the best blending ratio of fabrics, which providestechnical reference for the development of firefighters and SWAT underwear ofpolyimide fibers.Besides, provides a theoretical basis for its marketing.The specificcontent is as follows:Firstly, the properties of Polyimide fiber and viscose fiber, such as microstructuremechanical, moisture regain and so on were tested. The results show that, thePolyimide fiber has a excellent flame retardant performance, which is better thanviscose fiber, In addition its has good tensile performance. However, It also has someshortcomings, such as low moisture regain, high volume resistivity, which will lead tosome problems in the process spinning inevitably, such as electrostatic serious and soon. Since the flame retardant Viscose fiber with higher moisture regain and lowerresistivity performance which make it has a good spinnability. Flame retardantViscose mixed with Polyimide which not only can improve the workability of theproduct, but also reduce the price of the products significantly. So as to achieve thegoal of complementary advantages.Secondly, With development of flame retardant protective underwear as astarting point, spinning seven blended yarn with different proportions of Polyimidefiber/flame retardant Viscose fiber, then the performance of blended yarn were analyzed and compared.It shows that the breaking strength of blended yarns willincreases gradually with the increase of the content of Polyimide fiber. However, theevenness of blended yarns is gradually deteriorating, besides, the hairiness indexincreases too. In the process of spinning, it should pay attention to maintaining goodenvironmental temperature and humidity,In addition, the anti-static measures arenecessary.Seven fabrics were knitted with seven ratios of fabric Polyimide fiber/flame-retardant Viscose fiber, then the performances of flame retardant, thermo-hydrotransfer and the related indexes of mechanic were tested and analyzed, the resultsshows that the Polyimide fiber can significantly improve the flame retardantproperties of the fabric. The flame retardant performance of fabric is best whenPolyimide fiber content up to100%. With the increasing of polyimide content, themoisture-penetrability, water volatile ability, strength and dimensional stability ofblended fabric are increased,but the ventilation property, moisture absorption, wetability are overall decline and the pilling has a trend of deteriorating.On the otherhand, the fuzzy comprehensive sort and market factors were used to optimize the bestblended fabric. The results shows that the fuzzy comprehensive evaluation index of70/30proportion blended fabric is best of all.This proportion not only satisfies therequirement of flame retardant, but also has a great commercial development value.Finally, Optimizing the spinning process of Polyimide fiber/flame retardant viscose70/30on the basis of blending and blended ratio of optimizing. First of all, studying theprocess parameters of spinning processing through the single factor test andorthogonal test,such as the jaw separation of top and bottom pin, twist factor, backzone draft multiple, which will effect on the performance of the yarn., then getting theoptimum parameters of each factor by range analysis and variance analysis. Theoptimum spinning parameters as follow:the nip gauge is4.0mm; the twist factor is320, the draft multiple is1.06. In the end, the additional test verifies the feasibility andstability of the optimal process parameters combination.