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 ( CVFAP) caused by the fiber accelerated point variation during the drafting process was also calculated. A comparison has been made between CVFAP 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.

Study of sliver irregularity caused by fiber acceleration motion during the drafting process

“…In this study, the accelerated points of polyester fiber were tested by the tracer method. 19,20 The length of polyester fiber was 38 mm and every fiber had the same length. The fineness of the polyester fiber was 1.33 dtex and every fiber had the same fineness.…”

“…[14][15][16] Generally, the measurement of accelerated points of the floating fibers was conducted by the tracer fiber observation. [17][18][19][20][21] Theoretically, the distribution of the fiber accelerated points (DFAP) was described by various forms of distribution, such as the triangular distribution, 16 the parabolic distribution, 15 the log-normal distribution 17,22 and the normal distribution. 19,20 These studies mostly focused on the acceleration movement of floating fibers in the drafting zone, but did not involve the influence of the acceleration motion on the sliver irregularity during the drafting process.…”

Study on the influence of drafting forms in front drafting zone of ring spinning frame on fiber motion and yarn quality

“…Based on the two-velocity hypothesis, some other researchers tested the FAP distribution in a different drafting system with the method of the tracer fiber technique. [10][11][12][13][14][15] They are trying to build the relationship between the unstable movement of floating fibers and drafting parameters, and thus provide a basis for further research. It was found that the FAP distribution in simple roller drafting is more dispersed over a longer range, while the FAP distributions in the double apron drafting zone and the drafting zone with pressure bar are more concentrated and closer to front roller nip line.…”

Finite element modeling and experimental investigation between the novel drafting and double-apron drafting systems

“…Shen et al. 2 and Quan et al. 3 studied the dynamic movement of floating fibers during the double-apron drafting zone to understand better how the material properties or processing parameters affect the yarn quality.…”

“…Therefore, drafting theory and technology have attracted the considerable attention of researchers. Shen et al 2 and Quan et al 3 studied the dynamic movement of floating fibers during the double-apron drafting zone to understand better how the material properties or processing parameters affect the yarn quality. Yao et al 4 investigated floating fiber motion in various frictional fields, implying that different friction force distributions result in distinct distributions of fiber accelerations in the drafting zone.…”