喷气纺纱成纱机理研究

从50年代末美国 Du Pont 公司提出利用缠绕方法纺纱到现在,喷气纺纱在设备上得到了很大的发展。但是,对于这种纺纱方法的加捻与成纱机理的研究却是非常少的。本文提出了喷气纺纱过程中假捻区捻度形成的一种机理,可以用来解释单、双喷嘴情况下的捻度分布情况。通过对村田(孪生双喷嘴)及 Du Pont(单喷嘴)纺纱原理的对比研究,提出了包缠纤维的形成机理。分析表明,由于村田原理喷嘴的安排使第1喷嘴与前罗拉钳口之间纱线的自转与气圈回转的方向相反,推后了边缘纤维被纱线夹持的位置,使较多的边缘纤维有可能在纱线中成为有效的包缠纤维。进而阐述了喷气纱的特点:毛羽的单向性、包缠纤维及纱芯捻度的不均匀性、单、双喷嘴成纱条件和成纱质量的区别,主要纺纱参数对纱线强力的影响等。

STUDY INTO THE MECHANICS OF AIR-JET FASCIATION

Compared to the Du Pont fasciated yarn system,the Murata air-jet spinning employs a complex false twisting mechanism,in which a fibre bundle is twisted by the opposite operations of twin air-jets.The twist is primarily generated by the ballooning of the thread which is produced by the vortex air flow in the jets.This is further modified by the axial rotation of the thread.The twist characteristics in the twisting zone are the result of the two actions. The generation of edge fibres and the twist transference in fasciated yarn spinning are described,and a mechanism of fasciated yarn formation is suggested based on the comparison of the Du Pont and the Murata principles.In the yarn forming zone,the Murata principle provides a condition in which the interaction of the yarn axial rotation and the opposite ballooning delays the picking up of edge fibres by the twisting yarn core.This helps the production of more and longer wrapping fibres.The effects of some of the spinning conditions are also reported.