Using objective fiber property measurements at alternative processing stages to predict yarn quality

Abstract

The use of fiber property measurements in statistically based quality control programs for yarn manufacturing has become common during the past fifteen years. Movement of this approach into the management mainstream has been based largely on the availability of high volume instrument (HVI) data, which was designed and primarily used for raw cotton; i.e., ginned and baled cotton lint. Since HVI measurements are based on bundles of fibers, they are sensitive to sample preparation and technique. Therefore, using HVI measurements at any stage beyond the raw fiber state raises questions of measurement errors and the relative utility of the measurements [Duckett, et. al. 1993; Fryer and Rust 1996; Fryer, et. al. 1994; Lord and Rust 1994; Suh, et. al. 1993]. The development of the Advanced Fiber Information System (AFIS) provided the first commercial capability to focus automated measurements on individual fibers. This focus brought with it a greatly enhanced capability to get comparable measurements on raw versus partially processed fibers. Indeed, current uses of AFIS generally involve monitoring the effectiveness of the processing machinery and impacts on the fibers up through the finisher drawing [Oxenham, et. al. 1995]. Under controlled conditions within the spinning laboratories of the International Textile Center (ITC), the usefulness of alternative fiber property measurements at different stages may be authoritatively examined. The information obtained will enable progress toward (1) understanding the sampling and measurement effects on fiber property data and (2) improving the application of fiber property data to quality control management. Results reported here come from 156 samples of cotton from all over the world; 106 of the samples are from Upland cotton varieties and 50 samples are from extra long staple (ELS) cotton varieties. Since the research encompasses both Upland and ELS cottons, results were obtained for: (1) carded Upland and ELS cottons that were ring spun into Ne 36 yarns, (2) combed ELS cottons that were ring spun into Ne 50 and Ne 80 yarns,(3) carded Upland cottons that were ring spun into Ne 24 yarns, (4) carded Upland cottons that were rotor spun into Ne 18 and Ne 36 yarns, and (5) carded ELS cottons that were rotor spun into Ne 36 yarns. This report deals only with results for Upland and ELS cottons combined. Therefore, results are limited to the first category given above; i.e., carded cotton spun on the ring system to make Ne 36 yarns. This approach maximizes the range of data collected on objective fiber properties, which strengthens the statistical basis for drawing conclusions about the influence of these properties on spinning performance and yarn quality. Results specific to ELS cottons have previously been reported [Ethridge and Zhu, 1997; Zhu and Ethridge, 1997]. The research for these previous reports, as for this one, has been funded by an Advanced Technology Program project administered by the Texas Higher Education Coordinating Board.