Investigation on the tensile properties of individual cotton (Gossypium hirsutum L.) fibers

This thesis consists of three chapters. The first chapter covers introductory definitions on the subject of tensile properties of textile fibers. Concepts such as individual fiber tensile strength, fiber bundle strength, and instruments such as apparatus for measuring tensile properties of fibers, creep, and stress are briefly reviewed in this chapter. The aim of the second chapter is to determine the relationships between individual cotton fiber tensile properties and their length, maturity, and fineness, within-sample. To this end, six samples were selected among 104 reference cotton samples and each one was sorted into seven length groups using the array method. Tensile properties of each length group were tested using the FAVIMAT, the individual fiber tensile tester. In order to measure their maturity-ratio and fineness, samples were examined using the Advanced Fiber Information System (AFIS) Pro-2. It is observed in all samples that, within-sample, short cotton fibers have on average a lower tensile force. Also, within a sample, AFIS results indicate that longer fibers are on average more mature than shorter fibers. It can be concluded that throughout mechanical processing, the least mature cotton fibers may be broken into smaller segments. In the third chapter, we compared two common methods of testing fiber tensile strength, namely individual fiber and fiber bundle tests. Our objective is to investigate the relationships between individual fiber tensile force and other properties of cotton fibers and to identify the best predictors of individual cotton fibers’ tensile force using regression techniques. According to the results, almost two-thirds of the variability observed for the average tensile force of individual cotton fibers can be explained by fiber maturity and elongation.