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  • Fineness

    Chapter 2 - Cotton value addition - The impact of cotton fibre properties on textile 

    Cotton fibre fineness per se, which is determined by both genetic and environmental factors, has an effect on many aspects of processing performance, including spinning performance, and yarn and fabric quality. It is measured by double compression airflow tests as well as by single fibre ‘optical’ measurement systems, such as AFIS. Finer fibres, being more flexible and buckling more easily, entangle more easily to form neps, and break more easily to create more short fibres and fibrous waste, but improve spinning performance and yarn evenness and strength, mainly through the effect of the greater number of fibres in the yarn cross section, this being particularly important for very fine yarns and for rotor (open-end) and air-jet spinning systems. Spinning limits, in terms of the number of fibres in the yarn cross section, are 100 or more for rotor, friction and air-jet spinning and about half that for ring spinning. Finer fibres also enable lower roving and yarn twists to be employed, as well as being required for maximum yarn strength. Finer fibres also lead to yarns and fabrics which are more flexible (less stiff) and which have a softer handle. Fabric air-permeability is inversely related to fineness. The ideal, particularly for rotor spinning and fine yarns, is a very fine (< 150 mtex) but fully mature fibre.