The Relation between the Twist and Resistance to Repeated Extensions of Cotton Rotor-spun Yarns
The Relation between the Twist and Resistance to Repeated Extensions of Cotton Rotor-spun Yarns
复制标题
棉转杯纱捻度与耐反复延伸性能的关系
DOI：
10.1080/00405008108631649
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
A. Manich
中科院分区：
文献类型：
--
作者：
A. Barella;A. Manich
在一篇较早的文章中，我们研究了化纤转杯纱的加捻性能与抗反复拉伸性能之间的关系。本说明旨在完成关于转杯纺棉纱的研究。研究了两根分别为25tex和40tex的纱线的加捻倍数，其取值范围从103到221。所用棉花有效长度为30.5 mm，平均长度为24.2 mm，短绒率为21%，马克隆值为4.03。用这种棉生产的第二条并条机被送到BD200机的F-72转子上。如前所述，纺制了两根纱线，分别为25tex和40tex。在第一种情况下，喂入3.07ktex条子，总牵伸为121.55(实际纱线密度为25.26tex)。在第二种情况下，喂入4.67ktex条子，总牵伸为116.02，相当于实际纱线密度为40.22tex。在第一种情况下，应用的扭曲倍数为103.3、132.4、149.4、175.5和109.9，而应用的扭曲倍数为103.3、132.0。148.9,190.3。第二种是221.0。在这两种情况下，细纱机的最低加捻水平都出现了断头现象(分别有两个断头和一个断头)。转子转速为30000转/分。与前面报告的工作一样，在Comptiss仪器上进行重复拉伸测试，测试长度为300 mm，施加在纱线上的张力为1.5cN/tex，拉伸周期的幅度为5 mm(相对伸长率的1.66%)，频率为200周期/分钟。工作是在相对湿度和温度的标准条件下进行的，每根纱线测试了30个样品。图1中以断裂阻力和断裂伸长率的平均延伸周期数来表示结果。它如图所示。棉转杯纱的抗反复拉伸阻力随加捻程度的增加而增大。在这两种情况下都不存在
In an earlier paper^ the relationship between the twist and resistance to repeated extensions of man-made-fibre rotor-spun yarns was studied. The present note is intended to complete the study with regard to cotton rotor-spun yarns. Two yarns, of 25 and 40 tex, respectively, were studied for twist multipliers ranging from 103 to 221. The effective length of the cotton used was 30.5 mm, its average length 24.2 mm, its short-fibre content 21%, and its Micronaire index 4.03. A second-drawframe sliver from this cotton was fed to an F-72 rotor in a BD200 machine. As already indicated, two yarns were spun, these being of 25 and 40 tex. In the first case, a 3.07-ktex sliver was fed in, the total draft being 121.55 (the actual yarn linear density was 25.26 tex). In the second case, a 4.67-ktex sliver was fed in, and the total draft was 116.02, this being equivalent to an actual yarn linear density of 40.22 tex. The twist multipliers applied were 103.3, 132.4, 149.4, 175.5, and 109.9 in the first case and 103.3, 132.0. 148.9, 190.3. and 221.0 in the second. In both cases, there were end-breaks in the spinning frame at the lowest twist level (two breaksandonebreakperlOOOmof yarn, respectively). The rotor speed was 30000 r/min. Testing for repeated extensions was done, as in the work reported previously', on the Comptiss instrument, with a test length of 300 mm, the tension applied to the yarn being 1.5 cN/tex, the amplitude of the extension cycle 5 mm (1.66% of the relative extension), and the frequency 200 cycles/min. Work was done under standard conditions of relative humidity and temperature, and 30 samples of each yarn were tested. The results, expressed as the mean number of extension cycles to break, are graphically represented in Fig. 1 for both resistance and elongation at break. It is shown in Fig. I that the resistance to repeated extensions of cotton rotor-spun yarns tends to increase as the twist increases. In neither of the two cases is the presence