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  • 2.2.15-COTTON VALUE ADDITION-STICKINESS

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  • Stickiness

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

     
     

    Sticky cotton causes roller lapping and can have a very large adverse affect on processing performance, including both ring and rotor spinning. It may be caused by excessive quantities of plant sugars on immature cotton, but about 80% of the time is caused by honeydew (a sugar-containing sap secretion from insects, such as aphids or whiteflies), by high wax levels, or even by additives or contaminants (e.g. pesticides). Cotton-seed oil, from seed-coat fragments and seed motes, could also be related to stickiness problems. Storage and low levels of humidity during processing as well as certain additives (e.g. water, enzymes, surfactants and lubricants) can reduce certain stickiness related problems. Various tests are used for measuring stickiness, including:

    • Mini-card;
    • Thermo-detector;
    • Crush-rollers and image analysis;
    • pH;
    • Chemical/reducing sugar content (e.g. Clinitest, Perkins Method, Benedict Test and Fehling Tests), to provide a measure of non-honeydew related stickiness;
    • HPLC;
    • Discolouration upon heating.

    Nevertheless, there is a need for a rapid (high volume) means of measuring stickiness, (e.g. NIR). Measurement is complicated by the ‘non-uniform’ and ‘localized’ nature of stickiness, and the low levels and different types of contaminants which can lead to stickiness problems.