Study On The Spinning Feasibility Of PTT Short Fiber And The Property Of Corresponding Fabric

With increasing requirement of customers, elasticity is becoming an essential element for wider range of clothes. Today spandex is the most widely used material in the world because of its excellent elasticity. Owing to the high price, big investment, the complicated spinning process and other reasons, it is necessary to develop the lower elastic yarn and fabric to satisfy the requirement of customer.This thesis mainly studies the PTT (polytrimethylene terephthalate) cut fiber, which is one kind of modified polyester. Its elasticity is lower than that of spandex but higher than that of PET. Among the synthetic fibers, polyester becomes the first breed of synthetic fiber because of its excellent performance and lower price. PET and PBT have already been industry produced and widely used. PTT cut fiber integrate the rigidity of PET and suppleness of PBT. More attention has been paid to PTT for its' excellent flexibility and chromatophile.The main studies of this thesis are as follows:1 Diagnosed the developing possibility of PTT cut fiber2 Tested the strength/elongation of PTT and compared it with that of PET. Established the suitable model to describe the stress relaxation of PTT and got the relation between strain-stress and time.3 By some experiments on spinning with PTT short fiber and testing its strength/elongation property, tentative probes into the spinning ability of PTT short fiber. The minimum-blending ratio of PTT is 70% in term of elasticity.4 Tested the doff transfer rate of the carding machine, analysised the forceexerted on the fiber under carding process, and then calculated the front angleof wire clothing on cylinder.5 With the method of twisting and untwisting, try to find the critical twistfactor.6 By adjusting the density of fabric, finishing temperature and dying condition, found out the factors that affect the fabric's elasticity.According to analysis above, derived the following conclusions.1 The minimum-blending ratio of PTT is 70% in term of elasticity. But the best elasticity results are obtained by using 100%PTT staple fibers.2 By regression analysis, found the maximum critical twist factor on about 370.3 It is more advisable to use PTT staple yarn as warp. Strength and elongation at breaking point of the PTT fabric will increase with the finishing temperature. But after 60-65the strength and elongation at breaking point of the PTT fabric are stabilized.Generally, it is successful in the spinning of PTT cut fibers, but still need to do more research on PTT fabric's elasticity. Wish my work will do some favor to further study.