27FIBRES & TEXTILES in Eastern Europe July/September 2002 Influence of the Spinning Process Parameters on Strength Characteristics of Cotton Yarns

In this paper, the strength parameters of cotton yarns formed on the Rieter R1 spinning machine and on the Textima ring spinning machine were analysed. For the rotor spinning machine, the influence of linear density of the feeding sliver and of yarns on their specific strength, elongation and elasticity was evaluated. For the rotor spinning machine, the following parameters were used: ■ rotational speed of the rotor- 100,000 r/min (1666.7 r/s) ■ rotational speed of the opening roller- 7,000 r/min (116.7 r/s) ■ linear density of yarns: 18, 20, 25, 30 tex. The spinning machine was fed with slivers after the second passage of drawing with the linear densi-ties: 3.5, 4.0, 4.5, 5.0 ktex. On the ring spinning machine, yarns of linear densities of 25 and 40 tex were formed from the roving 400 tex. Analysis of the results for rotor-spun and ring-spun yarns showed that rotor-spun yarns are characterised by higher elasticity, which makes them a very good material for knitting purposes. Key words: rotor spinning, rotor spun yarn, yarn quality parameters, tenacity elongation, elasticity. Figure 1. Dependence of yarn breaking force o