COTTON-SLIVER STRENGTH AND WITHDRAWAL-SPEED LIMIT

Cotton slivers have very low tensile strength and are liable to unexpe cted drafting and breakage during processing. If the sliver stress is not appropriately controlled, poor sliver and roving evenness and freq uent end-breaks will occur. This paper reports on the experimental det ermination of the strength of cotton slivers at various processing sta ges and the influence of major drawing parameters on sliver strength. The investigation also revealed a close relationship between the depth of sliver-processing (reflecting fibre-straightening and fibre parall elisation) and sliver bulk. The estimated sliver tension on commercial high-speed drawframes can be as high as one-third of the strength of combed slivers and one-tenth of that of the carded slivers. The sliver -strength problem needs to he dealt with if further increases in drawf rame speeds are to be achieved.