Abstract:
Neps are clusters of fibres or entanglements of fibres. They are classified as biological neps, mechanical neps and white specks. Biological neps are those that contain foreign material; mechanical neps contain only fibres and are the result of mechanical manipulation during processing; and white specks are neps that are found as light or white spots on fabric due to their resistance to dyeing. Upwards of 90 % of visible neps in the dyed fabric contain immature fibre and appear as white specks. It had been estimated that the United States alone has lost as much as two hundred million dollars annually due to these dye defects. To develop predictions of white specks, large field-to-fabric studies have been undertaken jointly by the U. S. and Australia. A new image analysis system has been developed and provides quick and accurate measurements of the problem. Now, high-speed fibre measurements can be related to the fabric white speck level. Micronaire, detects extreme cases of white specks, but is more useful when the mature level of micronaire is known for an individual variety. AFIS also shows promise in detecting white speck potential Equations using micronaire and AFIS data are being developed to predict white speck. Meanwhile, variety, micronaire and level of cleaning should be tracked for all ginned cottons along with quality data from the end buyer or at least records of bales which industry has questioned as problematic for neps. This historical data will yield databases which will let the producer/ginner know what micronaire ranges are acceptable for their varieties. The information can be then be used to estimate whether or not a particular cotton is more prone to neps.
