|Robert Jr, Kearny|
Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2004
Publication Date: January 4, 2005
Citation: Robert Jr, K.Q., Dunn, M.C., Cosenza, F.A. Blending of cotton fiber samples. CD-ROM. Memphis, TN. National Cotton Council Beltwide Cotton Conference. 2005. Interpretive Summary: The more precise measurement of short fiber content (SFC) has been the major issue of concern in cotton length measurement for many years. Textile mill customers of U.S. cotton have strongly urged work in this area as vital to the industry. Existing measurements are useful, but not quite precise enough to be fully reliable for classing. Sample-blending procedures known to improve the accuracy and precision of cotton measurements have evolved over decades at the Southern Regional Research Center for various types of test equipment. A mechanical blending technique that was developed decades ago for manual sorting was applied in this work to the preparation of specimens for a modern computerized research instrument. The measurement of cotton length properties with that instrument was enhanced substantially by the blending technique. The precision of cotton short fiber measurements was thereby improved by a factor of two.
Technical Abstract: This experiment investigated the precision of laboratory sample-blending procedures for fiber length testing. It was built around a 2 x 2 x 2 cross-treatment design, comprising two sample-blending methods (hand blending and mechanical blending) and two specimen-extraction techniques (multiple pinch vs. single tuft) applied to two fiber forms (raw lint and sliver). In every case, a 10-gram blended sample was prepared. Each blended sample was exhausted by sequentially withdrawing twenty specimens of 0.5-grams each. All specimens were analyzed by the Advanced Fiber Information System (AFIS) length measurement instrument to determine the fiber length distribution. The experiment was replicated four times on each cotton tested. Variations in the complete length distributions by individual length interval, as well as the summary statistical properties were compared within methods (i.e., between samples) and within samples (i.e., between specimens). The proper choice of sample-blending and specimen-compositing approaches reduced the variation in length properties as measured by AFIS in raw cotton lint to approximately the level of variation obtainable directly from sliver. For comparison of mass determinations of length between 10-gram samples of raw lint from the same cotton bale, mechanical blending was found to have reduced the random variation in the measurement of short fiber content (SFC) by about a factor of two.