Cellulose fibers, such as cotton and linen, are abundant in farmer’s fields. The traditional bottom-up technology to process these short staple fibers is spinning. State-of-the-art spinning technology requires not only high throughput processing of the cellulose fibers, but also the addition of functionalities and value into the supply chain. Recently, a modified ring spinning system has been developed which introduces a false twist into a traditional ring spinning frame. The modified system produces cellulose yarns that have a high strength but low twist, and a soft hand similar to cashmere. Unlike traditional textile finishing treatments which consume plenty of chemicals, water, and energy, this method is purely physical and sustainable. The superior properties of the modified cellulose yarns are attributed to the modified yarn morphology and structure. Theoretical investigation is, therefore, important in understanding of the spinning mechanisms of the modified ring spinning process that changes the morphology and structure of the cellulose yarns. In this paper, yarn behavior constrained to lie on a moving solid cylinder was theoretically and experimentally investigated. Equations of motion were derived based on the Cosserat theory and numerical solutions in steady-state were obtained in terms of yarn spatial path, yarn tension, twist distribution, yarn bending, and torsional moments. Effects of various spinning parameters including wrap angle, speed of the moving cylinder, yarn diameter, yarn tension, yarn twist, and frictional coefficient, on yarn behavior were discussed. The results suggested that in most cases the bending and torsional moments are of the same order of magnitude, and thus the effect of bending cannot be neglected. Experiments in the modified ring spinning system were conducted to verify the theoretical work, and good agreement has been made. Some simulation results of this study were compared with the results of earlier models as well as with experimental data, and it was found that the current model can obtain a more accurate prediction than previous models in terms of yarn twist and tension. The results gained from this study will enrich our understanding of the spinning mechanism of the modified ring spinning process and better handle of cellulose fibers for functional and value-added applications.

纤维素纤维，例如棉和亚麻，在农民的田地里很丰富。处理这些短短纤维的传统的自下而上的技术正在纺丝。先进的纺纱技术不仅需要纤维素纤维的高通量加工，而且还要求在供应链中增加功能和价值。最近，已经开发了一种改进的环锭纺纱系统，该系统将假捻引入传统的环锭纺纱机中。改进的系统可生产出具有高强度，低捻度和类似羊绒的柔软手感的纤维素纱。与消耗大量化学药品，水和能源的传统纺织品后整理处理不同，此方法纯粹是物理上可持续的。改性纤维素纱的优异性能归因于改性纱的形态和结构。因此，理论研究对于理解改变环锭纺纱工艺的纺丝机理很重要，该环锭纺工艺改变了纤维素纱的形态和结构。本文从理论上和实验上研究了受约束位于移动的实心圆柱体上的纱线行为。基于Cosserat理论推导了运动方程，并根据纱线的空间路径，纱线的张力，捻度分布，纱线的弯曲和扭转力矩获得了稳态下的数值解。讨论了包角，动筒速度，纱线直径，纱线张力，纱线捻度和摩擦系数等各种纺纱参数对纱线行为的影响。结果表明，在大多数情况下，弯曲力矩和扭转力矩具有相同的数量级，因此弯曲的影响不可忽略。在改进的环锭细纱机系统上进行了实验以验证理论工作，并取得了良好的一致性。将该研究的一些模拟结果与早期模型的结果以及实验数据进行了比较，发现在纱线捻度和张力方面，当前模型可以比以前的模型获得更准确的预测。从这项研究中获得的结果将丰富我们对改性环锭纺丝工艺的纺丝机理的理解，并更好地处理功能性和增值应用中的纤维素纤维。