Further Studies of Mechanical Damage on Machine-Harvested Cotton Fiber via Coupling Effect of Moisture Regains and Low Temperature

Cotton is a crucial raw material for the textile industry, and the quality of its initial product greatly affects the properties of the yarn and fabric. However, the impact of low temperature and moisture regain during ginning on the mechanical properties has not been extensively studied. This paper aims to address this gap by designing and analyzing a strategy for evaluating the mechanical properties of machine-harvested cotton fibers pretreated at different moisture regain levels and temperatures. Regression models for the relationship between temperature and mechanical properties under different moisture regain conditions were also established, showing good consistency. Additionally, the study examines the mechanical damage mechanism of cotton fibers during the harvesting and ginning process by observing the fiber fracture interface of different samples. Especially, those with low moisture regain exhibit a V-type fracture, while those with high moisture regain display significant fibrils exposed on the fiber body, resulting in a tearing morphology at the fracture interface. In conclusion, this study provides theoretical support for optimizing the harvesting process in cotton processing enterprises in terms of moisture regain and low temperature and makes a significant toward sustainable cotton fiber harvesting and processing technology.