Fiber motion and the accelerated point distribution in roller drafting

In this study, the tracer fiber method was used to determine the accelerated point distribution in both the break draft and main drafting zone of the drawing frame with varying different draft parameters. Viscose, cotton, and polyester slivers were used respectively. For the different parameters, the tracer fibers of known length were embedded in the single sliver strand, and measurements of their positions before and after drafting were taken. These measurements of the positions of tracer fibers before and after drafting were then used to deduce the nature of the fiber movement, thus determining the distribution of the accelerated points. The accelerated point distribution under different parameters was obtained. Gauss distribution was found to suitably describe the accelerated point distribution curve under different parameters used in this study. The pressure bar to some degree imparts a significant control of floating fibers within the drafting zone. The relationship between the sliver unevenness and the accelerated point variance (CV) was also discussed.