Research On Ring Spinning Tirangles And Its Effects On Yarn Qualities

Nowadays, the ring spinning technology was widely used for its simple mechanicalstructure, strong adaptability and good quality. In the ring spinning process, the travelersrotated and the yarns were twisted by the movement of the travelers. The twist were deliveredto the front roller nip along the yarn, at the same time, a soft twist zone generated in front ofthe front roll nip named the twisting triangle. The twisting triangle is an important area andhad an important influence on the properties of yarns, such as hairiness, breaking strength andresidual torque. In view of this, the high-speed photography technology has been used in thispaper, and the clear images of the twisting triangles of the traditional ring spinning system andthe modified ring spinning system by airflow were photographed. The geometric parametersof the twisting triangles were measured and the distributions of fiber tensions were simulated.All above provided references to the optimization of the twisting triangles’ shape.Firstly, the transparent cots were used to replace the ordinary cots, and the clear picturesof the different twisting triangles were taken with the help of high-speed camera. Throughthese pictures, we could obtain the shapes of the twisting triangles of the traditional ringspinning system at different spinning speeds, front impulse values of cot and twist multipliers.We could also obtain the shapes of the twisting triangles of the modified ring spinning byairflow including the twisting triangles’ shapes of pneumatic compact spinning at differentnegative pressures and the airflow false-twist spinning at different airflows. Then, by filmingand measuring the scale paper of1mm1mm, the magnification multiples of the actualpictures and the actual dimensional parameters of the different twisting triangles wereobtained. Then, the distributions of fiber tensions were described by simulation. Finally, theproperties of yarns were measured and their relationship with the shapes of twisting trianglesand the distributions of fiber tensions were discussed and analyzed.The results are as follows:(1) For the traditional ring spinning, with the increasing ofspinning speeds and twist multipliers and the decreasing of the front impulse values of cots,the height of the twisting triangles and the number of hairiness were increasing. With theincreasing of the twist multipliers and the front impulse values, the tensions of fibers at theedge increased gradually and exceeded the maximum load, which caused the breakingstrength increased firstly and then decreased. With the increasing of twist factors and thedecreasing of the front impulse values, the ranges of the distributions of fiber tensions and thetension gaps between fibers on both sides increased witch caused the number of the wetsnarling increasing.(2) For the modified ring spinning by airflow, the shapes of the twistingtriangles and the distributions of fiber tensions were obviously different by the differenteffects of airflow. For the pneumatic compact spinning, the shapes of the twisting triangleswere smaller than the traditional ring spinning’s. With the increasing of the negative pressures,the height and width of the twisting triangles decreased and the ranges of the distributions offiber tensions increased, which caused the number of hairiness decreased. For the airflowfalse-twist ring spinning, by the effects of left airflow, the height and width of the twistingtriangles decreased, which caused the number of hairiness decreasing. At the same time, theoffset distances of the twisting triangles and the range of the distributions of fiber tensions were increasing, which caused the number of wet snarling increasing. By the effects of rightairflow, the height and width of the twisting spinning increased, which caused the number ofhairiness increasing, and the offset distances of the twisting triangles and the range of thedistributions of fiber tensions decreased, which caused the number of wet snarling decreasing.