An improved model for the limiting irregularity of wool yarns

摘要

The limiting irregularity of a yarn is the minimum count variation expected from an ideal yarn with a random fiber distribution. It is calculated with the Martindale limiting irregularity model, which takes into account the changes in the number of fibers in yarn cross-sections and between-fiber diameter variation. However, within-fiber diameter variation is not incorporated into the calculation. Wool fibers exhibit diameter variations both between fibers and within a fiber. Ignoring the within-fiber diameter variation may lead to underestimating yarn limiting irregularity. This paper reports an improved model for calculating the limiting irregularity of wool yarns, incorporating both between-fiber and within- fiber diameter variations of the constituent wool fibers. Experimental verification shows that this model can predict the yarn limiting irregularity more accurately than the existing one.