Effects of Staple Strength and Raw Wool Blend Make-Up on Processing and Properties from Top to Fabric

Abstract

The impact of staple strength on later stage processing of fine fleece wools (19 µm) and the blending with pieces is investigated. The staple strength findings complement those of previous researchers who used wools of different fibre diameters or from single flocks. The results reported here show that, as previously, the direct effect of staple strength is limited to the production of tops, where staple strength influences fibre length in the top and the generation of combing waste. Blending fleece wool and pieces was shown to increase combing noil and reduce fibre length in the top. The topmaking results conducted at CSIRO suggest that there may be an economic advantage in incorporating lower staple strength, and hence cheaper wools, in an all-fleeces consignment while still being able to meet the technical requirements for yarn and fabric production. Although statistically significant, the small tenacity and elongation differences for 1/64 Nm yarns produced from the high and low staple strength test batches appear to have had no significant impact on the fabric tensile properties. There were no inter-batch yarn evenness and fault level differences recorded, with top dyeing having a much greater influence on yarn quality than any differences associated with staple strength. Blending fleeces and pieces in a 60/40 ratio had a greater impact on processing from raw wool to fabric than the effect of staple strength over the range investigated. In comparison to an all-fleeces batch it would appear the economics of processing a fleeces-and-pieces batch may not be attractive, as the blend composition had an adverse effect on yarn fault levels, tenacity and elongation, which in turn may adversely affect weaving performance. However, the effect on fabric properties appears to be minor.