A simple model of the worsted drawing and spinning sequence has been developed, which takes account of the various components of irregularity at every stage of processing. The model can be used to determine how well each processing step is performing, and to identify ways of improving the overall performance of the whole processing sequence from top to yarn. The model has been used successfully to identify the source of a problem in a commercial semi-worsted line. The model is also useful for defining the quality of slivers at any stage of processing, and the quality of the product yarn. Quality is commonly defined by the Index of Irregularity, as first defined by Martindale. It is shown that the Index is imprecise between yarns of different count and fibre content, and cannot relate the quality of slivers to that of rovings to that of yarn. An alternative measure of quality is proposed which is easily calculated and realistically defines the quality at any stage of processing.
By: J Lappage, MSc, PhD, FTI Wool Research Organisation of New Zealand
Submit Date: 6/7/2010 18:00