Study On The Technology And Properties Of Yarns Reproduced Using False Twist Draft

At present,there are many problems in superfine yarn spinning technology,such as more equipment modifications,more processes,higher requirements for raw materials and higher production costs.Reducing the equipment requirements and simplifying the process can help to reduce the technical threshold of spinning superfine yarn.In this paper,based on the false-twist drafting process,a spinning technology of yarn secondary processing based on the yarn in the finished product is designed and a small spinning prototype based on the spinning principle is produced.Then a variety of cotton yarns with different process parameters were spun on a sampler using 28.1 Tex cotton single yarn as raw material.By selecting three main influencing factors in the process of spinning: degree of untwisting of false twister,draft multiple,front and back roller spacing,three levels of each influencing factor were selected for orthogonal experiment.Then according to the direct analysis,variance analysis and mean analysis,the fineness,hairiness,evenness,strength and bending stiffness of the yarn were analyzed one by one to find out the influence degree of the three influencing factors on the performance index of each yarn,and the corresponding optimal spinning process scheme was selected.Draft multiple is the significant influence factor of yarn fineness,hairiness,strip and strength,and the secondary significant influence factor of yarn bending stiffness.The degree of untwisting is a significant factor influencing the bending stiffness of the yarn,and it is also a secondary significant factor influencing the fineness and strength of the yarn.The draft spacing plays an auxiliary role in improving the yarn quality and has a great influence on the yarn hairiness and yarn length.To obtain yarn with more balanced yarn performance.The rotating speed of the false twister shall not be more than 2/3 of the product of the slip twist of the original yarn and the spinning speed of the yarn,the drafting times shall not be more than 20 times,the front roller spacing shall be controlled within 1.5 times of the average length of the original yarn,and the length of the rear roller spacing shall be controlled within 2 times of the quality length of the original yarn.Based on the experimental data,the linear regression model between four main influencing factors and performance indexes was established for each yarn performance index,which was used to predict the approximate performance of yarn after the change of process.The simulation results show that the model has a good fitting effect.Finally,through the comparison between the sample and the original yarn,this paper finds that after adopting the spinning method described in this paper,while effectively reducing the fineness of the yarn,the hairiness of the yarn is significantly reduced,the breaking strength is significantly increased and the bending stiffness is also reduced,and the evenness of the yarn was lower than that of the original yarn.After further improvement,it has the prospect of spinning superfine yarn at low cost.