%0 Journal Article %T Effect of Some Navels on Properties of Cotton/Nylon66 Blend (1£¿:£¿1) Rotor Spun Yarn and Wrapper Formation: A Comparison between Rotor and Ring Spun Yarn %A Babak Yadollah Roudbari %A Safdar Eskandarnejad %J Journal of Textiles %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/262635 %X Use of nylon/cotton blend yarn in military uniform is common and due to advantages in its fabric in comparison to 100% cotton fabrics, capabilities of military uniforms have been improved. In this study the effects of navel type on properties of (50%-50%) nylon/cotton blend yarn and wrapper formation were investigated and compared with similar ring spun yarn. Rotor spun yarn was produced on a single head laboratory rotor spinning machine with four navels (smooth, spiral, 3 grooved, and 4 grooved) and ring yarn was produced on a zinser 319 ring spinning machine. Test result showed that navel type has a significant effect on yarn strength and strength of smooth navel yarn was maximum. Elongation of a 100% cotton rotor spun yarn is more than similar ring yarn, but it was not observed in cotton/nylon blend. Yarn irregularity and imperfections varied significantly with navel type and for rotor yarns were more than the ring yarn. Navel type had significant effect on yarn hairiness but it didnot have an effect on yarn abrasion significantly. 1. Introduction The use of blended yarn has increased significantly these days. Blending is used as a means of substituting a less expensive fiber for a highly priced one and to produce yarns with qualities that cannot be obtained by using one type of material alone. El-sheikh [1] reported that the properties of blended yarns depend on their constituent fibers and also showed that blended yarn¡¯s tenacity decreases as the percentage of high tenacity fiber is increased. Kemp and Owen [2] investigated the stress/strain characteristics and cotton fiber breakage for a series of nylon/cotton blended yarns at strain above the breaking strain of all cotton and also studied the strength and mechanical behavior of nylon/cotton blended yarn and they found that a dependence exists between the behavior of the two fiber types. Gibson et al. [3] worked on military uniform and reported that nylon/cotton blend is used as an outer shell in different version of military chemical protective uniforms. And some researchers [4¨C6] worked on battle dress uniforms (BDU) and found that nylon/cotton blend is more suitable than those of any other blends. Kong et al. [7] reported that by adding 2¨C4% elastan yarn (lycra) through the nylon/cotton fabrics, the ability of extension of these kinds of fabrics can be increased up to 50% and it is appropriate for military uniforms. Javadiyan et al. [8] worked on seven different nylon/cotton blend ratios and reported that by increasing the nylon fiber blend ratio, the yarn elongation, abrasion resistance, %U http://www.hindawi.com/journals/jtex/2013/262635/