Abstract:

Pneumatic compact spinning is the most widely used compact spinning technology at present, which is implemented by using negative airflow to condense the fibre bundle and decrease the spinning triangle. Roller-type and Lattice apron-type compact spinning are two major kinds of pneumatic compact spinning now. In this paper, blend yarn qualities spun by one kind of roller-type compact spinning: complete condensing spinning (CCS), and one kind of Lattice apron-type compact spinning: 4-line rollers compact spinning (FRCS) were studied and analysed comparatively. First, 28.1, 18.5 and 12.3 tex JC60/T40  blend yarns and 18.5, 14.8 and 11.8 tex JC35/T65 blend yarns were spun on two kinds of compact spinning systems, respectively, and the effects of the blending ratio on yarn qualities were discussed. Then another two kinds of cotton blended yarns - JC60/R40 and  JC60/M40 were spun. 28.1, 18.5, 14.8 tex JC60/R40 and 18.5, 14.8, 11.8 tex JC60/M40 were spun on two kinds of compact spinning systems, respectively. Meanwhile the qualities of spun yarns were analysed by using two methods. First with a high speed camera system - OLYMPUS i-speed3 (OLYMPUS Image Co., Ltd., Japan), the condensing process of  a fibre strand in the condensing zones were captured and analysed. Second the cross sections of the spun yarns were presented using a Y172 Hardy’s thin cross-section sampling device (Nantong Hongda Experiment Instruments Co., Ltd., China). The corresponding Hamilton Index was then calculated, and the fibre radial distributions in the yarn cross section were analysed. The results show that the fibre condensing effects are increased with an increase in the ratio of cotton fibre on the blended yarn for both kinds of compact spinning, especially the FRCS. Meanwhile with an increase in the ratio of polyester fibre on the blended yarn, the advantage of CCS with respect to yarn qualities increased. For both JC60/R40 and JC60/M40, cotton fibres are transferred to the outer part of the yarn body. However, the fibres in JC60/R40 yarn spun by CCS and those in JC60/M40 yarn spun by FRCS are distributed more randomly.