Composite yams

Zhang, H.X., Xue, Y., Wang S. Y., 2006. Effects of twisting parameters on characteristics of rotor-spun composite yams with spandex. Fibers and Polymers, 7, 66-69. 

Composite yams can be defined as a stractured yam consisting of a minimum of two strands of yams, one forming the core, or centre axis, of the yam, and the other strand(s) forming the cover yams. To prevent the core from breaking out, the cover members are wrapped around the core in a manner that the successive cover members can be wound over the underlying cover yams. This second cover member is wound in the opposite direction to the cover member lying underneath it (Fig. 7.11). 

The classification of the composite yams is shown in Fig. 7.12. Several systems exist to manufacture the different types of composite yams. Some of the well-known systems are DREF spinning types I, II, and III, wrap spinning, modified ring spinning, modified core spinning, and braided yams. " "... 

The properties of composite yams differ according to the arrangement of their materials and the combination of the properties of the different yams used. They are typically used where high mechanical performance or multifunctional performance is necessary. In a composite yam, the core filaments contribute the most to the mechanical performance and cover staple fibre or filament yams contribute least. The cover staple fibre or filament yams provide any additional properties such as skin-friendly surface, surface insulation, good handle, etc. ... 

Since no single fibre can provide all the properties expected for a highly protective and yet comfortable product, composite yams using different compositions were developed. The different types of composite yams that were initially analysed are listed in Table 7.5. 

Wykes E669 is a development composite yam that was mainly used to study the effect of stainless steel core which is widely used in knitting to provide cut resistant properties. 

Composite yams in the WF series of yams were spun specifically for the purpose of this research by using a vertical hollow spindle covering machine of a type manufactured by the H H Arnold Company. This machine has been modified by World Fibre Inc, USA using a proprietary technique as described in the US Patent No. 6,413,636. ... 

Kevlar series Tilsa series Wykes E669 WF series Staple fibre Kevlar yams Continuous filament double ply yams Composite yam with steel core Composite yams with a minimum of three components Aramex-Game, Germany Tilsatec, UK Wykes, UK World Fibre Inc, USA... 

The main components in the WF series yams are glass fibres and UHMWPE. They were constructed in different mass per unit length (linear density) combinations in order to analyse a range of permutations. The composite yams were double covered with either polyester or polyamide to have a better handle and also to enable dyeing the external surface of the fabric. Polyamide 6,6 was preferred as the covering yam as it has a higher melting point (263 °C) than polyamide 6 (216 °C). Polyamide 6,6 also provides excellent wear resistance and frictional properties. ... 

Since para-aramid yam is the most widely used yam in cut resistance fabrics, ring spun staple fibre aramid yams were chosen to be used in one face of the weft-knitted fabric. A composite yam had to be used for the other face of the fabric. It is imperative that the most suitable yams for each face of the fabric are chosen. 

Fig. 7.19 Stress/strain curves of composite yams with stainless steel core.

Apart from the yams containing a stainless steel core, two other types of composite yams were tested, the first being a two-ply yam, where two types of yams were twisted together, and the second an advanced composite yam, where a minimum of three components are used to make up a yam. Schematic diagrams of both types are shown in Fig. 7.20 (a) and (b). 

Several different compositions of the advanced composite yams were manufactured in order to compare their tensile properties. The stress/strain curves for these yams are shown in Fig. 7.21. The Tilsatec yams are two-ply composite yams and WF series yams are advanced composite yams. 

Fig. 7.20 Composite yams (a) two-ply composite yam (b) advanced composite yam (reproduced with permission from Superior Glove Works Ltd). ...

Fig. 7.21 Stress/strain curves for two-ply and advanced composite yams.

As a part of this programme, composite yams were developed and the results showed that the properties of the yams greatly influence the slash resistant properties. Further work could be conducted by concentrating solely on the yams and in studying the cut resistant properties of the yams. The combination of fibres used in the composite yams could be altered to further reduce the fabric area density and also to enhance the comfort of the fabric. 

Bontemps G, Francois M, Guevel J, Kriele JEA. Composite yam with high cut resistance and articles comprising said composite yam. European Patent EP0445872 Bl 11 December 1996. 

Weng W, et al. Winding aligned carbon nanotube composite yams into coaxial fiber fiiU batteries with high performances. Nano Lett 2014 14(6) 3432—8. 

E-broidery, embroidery with conducting threads, is described by Post (1996) and Post et al. (2000). The sewability of various electrically conducting yams is compared. Stainless steel threads have advantages because of their resistance to corrosion, biological inertness, availability in textile form and low cost. However, it is difficult to attach them to existing components. Composite yams made from steel and polyester can be sewn by machine (Post et al., 2000). 

Melt spinning is most applicable when polymer yams are spun from thermoplastics such as nylon, polyethylene, polyester, cellulose triacetate, and PET, to name afew. Also, note that although some ICP complexes (e.g., PANI-DBS A composite) are not thermoplastics, they can still be used as conductive additives in melt spinning to produce conductive polymer composite yams (see Section 2.2.3.S). In melt spinning (Figure 2.7), the raw polymer materials are heated to form a polymer melt with a viscosity suitable for extm-sion through the spinnerette into an air chamber. Then, the extmded polymer streams cool... 

Consoli, O., Coulston, G., Karayianni, E., Regenstein, K., 2004. Electrically conductive elastic composite yam, methods for making the same, and articles incorporating the same. U.S. Patent, US20040237494 Al. 

One approach to dramatically increase the electrical conductivity of CNT yams is to apply a metal coating on the pure CNT yams. Randeniya et al. (2010) reported a composite yam with high electrical conductivity by self-fuelled electro-deposition of metal nanoparticles onto a dry-spun CNT yam. Cu-CNT and Au-CNT composite yams prepared by this method had metal-Uke electrical conductivities (2-3 x 10 S/m). However, the tensile strength of the composite yams was 30-50% lower than that of the original CNT yam. 

Randeniya, L.K., Bendavid, A., Martin, P J., Tran, C.-D., 2010. Composite yams of multiwaUed carbon nanotubes with metallic electrical conductivity. Small 6, 1806-1811. 

Textile Fibers, Dves, Finishes, and Processes Integrated Composite Yam Spinning... 

What differentiated ICS from other composite yam formation systems was that the process was designed to integrate a staple fiber component into... 

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