EVAULATION OF SHORT FIBER MEASUREMENT METHODS

Given the cotton industry’s need for a meaningful short fiber measurement, the USDA, AMS, Cotton Program in Memphis, Tennessee and the USDA, ARS, Cotton Quality Research Station (CQRS) in Clemson, South Carolina have assembled a study to evaluate available short fiber measurements relative to each other and relative to textile processing performance. Twenty-nine U.S. grown Upland cotton bales have been selected to represent a wide range of length and short fiber contents. These bales have been tested in USDA, AMS cotton calibration value setting testing procedures to obtain HVI measurement levels referenced to established USDA benchmark reference cottons. Study participants from various cotton fiber testing labs within and outside the U.S. have been asked to test samples from the study bales on instruments including HVI, AFIS, Schaffner Isotester Li, Lintronics FiberLab and the Suter-Webb Duplex Cotton Fiber Sorter (array method). The 29 bales will be processed in a textile spinning plant to determine bale utility value. Initial results, from data being submitted by participants, are showing good correlations between methods. However, different test levels exist between instruments. Processing of the cottons is scheduled to begin in the spring of 2004. The intent of this report is to explain the study plan and to provide a preliminary look at some of the early data collected so far. Objectives The ultimate objective of this study is to determine the sensitivity of short fiber measurement methods relative to spinning performance. In addition, by utilizing multiple measurement methods on a common set of cottons, sensitivity and short fiber measurement characteristics between the methods can be compared. In cases where more than one instrument of the same type is evaluated, sensitivity and characteristics within an instrument type will also be evaluated. In this study, most of the measurement methods will take advantage of maximizing their sensitivity given the opportunity of performing high testing repetitions on each bale. Although this may lead to measurement sensitivities that are not realistic in lower repetition testing applications such as cotton classification, finding the potential of a measurement’s sensitivity is a critical first step in developing a practical short fiber measurement. The U.S. grown Upland cottons selected for this study represent a wide range of fiber lengths, short fiber contents and combinations of both properties. Figures 1, 2 and 3 show the distributions of properties based on AMS HVI study results. Given the wide range and varying combinations of length characteristics in the study bales, the potential for a meaningful short fiber measurement assessment is good. Methodology A total of eight participants are involved in providing testing on cottons sampled from a set of 29 U.S. Upland cottons. The participants are Cirad in Montpellier, France; Cotton Incorporated in Raleigh, NC; Gdynia Cotton Association in Gdynia, Poland; International Textile Center in Lubbock, TX; Lintronics, LTD in Arad, Israel; USDA, ARS, CQRS in Clemson, SC; USDA, ARS, SRRC in New Orleans, LA; and USDA, AMS, Cotton Program in Memphis, TN. As of this writing, sample testing and textile processing remains in progress. Therefore, this report will provide some analysis on only the data collected so far. Full presentation of results will come after all testing is completed. A total of 10 test sets were assembled for distribution among the participating laboratories. Each participating laboratory was given one set. Each test set was made up of a total of 290 samples (29 bales x 10 samples/bale). Individual sample weights were from 150 to 250g. Bale sampling was performed by pulling 10 samples from 10 regions across the bale “fanhead”. Ten samples from each of the 29 bales were previously screened by 9 HVI systems to insure that the bales had a high degree of uniformity. In addition to short fiber measurements, all other available measurements provided by each instrument (e.g. micronaire, neps, strength, etc.) were performed on the test samples. Each instrument used in the study was calibrated prior to sample testing according to each lab’s normal operating procedures. Calibration cottons (based on AMS established values) were provided, but were not required for calibration.