Measurement of Cotton Fiber Tenacity on 1/8 Gage HVI Tapered Bundles

Abstract

The inherent precision and accuracy of the methods used for measuring the fiber bundles strength of cotton encompass the variability among individual measurements and the confidence with which the measurements can be used to predict the strength of yarn or fabric. A high volume instrument developed for measuring the length characteristics of cotton fiber in tapered fiber beards was used to break the same beard for a measure of fiber strength. A method of breaking fiber bundles at a predetermined distance from the sampling clamp was compared with the conventional method—breaking a predetermined number of fibers. Sources contributing to variability of both measurements were defined, analyzed, and compared to sources of variability in Pressley and Stelometer measurements of the same cotton samples. All methods of measuring bundle strength were evaluated for accuracy as predictors of yarn strength for both open-end and ring-spun yarns. Data agreed closely between two methods tested with the high volume instrument. Data from conventional testers (Pressley and Stelometer), however, were better predictors of yarn strength than either HVI method.