Comparison of dual-feed-opening rotor spinning with varying fiber-transfer channel angle: Evaluation of airflow numerical simulation and yarn characteristics

The emergence of dual-feed-opening (DFO) rotor spinning has garnered notable attention in the area of innovative spinning techniques. In this research, we delved into the effects of the angle between two fiber-transfer channels (FTCs) on airflow dynamics, yarn structure, and other properties within a DFO rotor spinning system. Computational fluid dynamics simulation revealed that a 110° angle created an asymmetric airflow, marked by pronounced vortices and localized high-pressure zones, which diminished yarn tenacity to ≈11.6 cN/tex and increased unevenness to over 16%. In contrast, samples 18BW and 18WB demonstrated superior performance in hairiness index and imperfections. Digital image processing analysis indicated that, at a 110° FTC angle, fibers from feed roller 1 were more likely to accumulate on the yarn surface. Conversely, symmetrical FTCs produced a consistent airflow, promoting a uniform fiber arrangement, regardless of the feeding method. The ratio of the area occupied by two different colored fibers in the yarns was close to 1. This investigation holds significant importance in the advance of rotor-spun yarn development.