Filament pre-tension in core yarn friction spinning

Core yarns are known to improve cotton yarn properties. In this research, core yarns are spun by introducing filaments under tension into the yarn-forming zone of an experiment al friction spinning apparatus. A 30-denier (3.3 tex) nylon monofilament and st black 75-denier (35f) nylon multifilament make up the core, and cotton fibers are used as the sheath, The effect of filament pre-tension on the structural parameters and mechanical properties of the core yarn is examined, and core yarn properties are compared with those of equivalent 100% cotton yarns. The photographic and fiber tracing methods are used to consider the appearance of the yarns and the geometric position of the core in the core yarns. The results show that the appearance of the core yarn is similar to that of regular cotton yarns, with the exception of core yarns produced with 00 gf/fil pre-tension, Core yarn irregularity does not change with filament pre-tension, and it is less than that of cotton yarn. Core yarn strength significantly increases as filament pre-tension and filament percentage increase, and it is greater than that of cotton yarn. Core yarn elongation is less than that of cotton yarn at a low filament percentage and greater than that of cotton yarn at a high filament percentage.