自由端摩擦纱捻度结构的理论分析

The Theoretical Analysis of the Twist Structure of the Free-end Friction Yarn

本文根据在自由端摩擦纺凝聚和加捻过程中纤维的运动规律，推导获得了摩擦纱捻度结构的理论公式。由此公式所得到的摩擦纱的捻度结构形式为外层蓬松，中层紧密，核心无捻。这一结果与实验结果相一致。本文分析表明，摩擦纱这一独特的捻度结构的产生原因是当纤维进入纱尾时将不可避免地发生反向捻回现象，这一现象也是导致摩擦纺加捻效率甚低的主要原因。

This paper presents a theoretical formula about the twist structure of the free-end friction yarn by analysingthe movement of a fibre in the depositing and twisting process of a forming friction yarn. The formula shows that thecross section of the friction yarn can be roughly divided into three layers,namely no-twist core,the tighter middle layerand the looser out layer. The conclusion shows a good agreement with experimental results. It is also pointed out thatthis kind of Peculiar twist structure is caused by the fact that there is a reversing twisting process with the entrance thefibre enters into the taper tail of the yarn. The fact also constitutes the main reason why the friction spinning has muchlower twisting efficiency than other spinning methods.