Study on the testing of the accelerated point of the floating fiber in the roller drafting process with an improved method

Abstract

The dynamic motion of floating fibers in the drafting process, which can be characterized by fiber accelerated points, has an important effect on the sliver or yarn quality. In this study, the fiber accelerated point during the roller drafting process has been tested with an improved method. In this method, tracer fibers and standard tracer yarns of known length were embedded into the sliver in groups. By adjusting the length and fineness of the standard tracer yarns, it was possible to determine the nip line of the front roller dynamically. Therefore, the fiber accelerated points can be obtained in a continuous drafting process without an external sensor, which is simpler and more convenient, and avoids the experimental error caused by the drawing frame shutdown during the experiment. Based on this method, the effects of the drafting parameters and sliver properties on the fiber accelerated point in the roller drafting process have been investigated. In addition, the coefficient of variance of the sliver (CV_FAP) caused by the fiber accelerated point variation during the drafting process was also calculated. A comparison has been made between CV_FAP and the standard deviation of the fiber accelerated points. It is found that a fairly good agreement between these two is seen, and this agreement can also evidence the accuracy of experimental results about the fiber acceleration point.