Ring Spinning

In the next processing step, the flyer yarn is pulled off the flyer bobbins that are creeled on a frame and fed to the ring spinning machine. 

The vertical movement necessary for yarn winding is accomplished by the ring rail. To produce a cop winding that allows unwinding in further processing at high speed and without breaks, the ring rails follow a defined pattern of vertical movement. A pattern of vertical movement often used is depicted schematically in Fig. 3.15. 

The maximum production of ring spinning is limited by the maximum velocity of the traveler, which is about 40 m/s today, producing local temperatures of up to 450°C. At higher traveler temperatures the heat produced by friction cannot dissipate sufficiently, which will result in the destruction of the traveler or the yarn. 

For the production of woolen yarns, ring spinning can also be economical owing to their relatively low twist, which reduces the economic advantage of nonconven-tional spinning machines. 

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Wisniewska, A., Y. Nishimoto, J. S. Hyde, A. Kusumi, and W. K. Subczynski. 1996. Depth dependence of the perturbing effect of placing a bulky group (oxazoline ring spin labels) in the membrane on the membrane phase transition. Biochim. Biophys. Acta 1278 68-72. 

The NMR spectra of all of the parent naphthyridines (l)-(6) can be interpreted by first order splitting rules including meta, para and cross-ring spin-spin coupling. The various chemical shifts are shown in Table 4. As it is now common practice to report H NMR data of naphthyridine derivatives, which are far too numerous to list individually, further information can be obtained from the references given in the table as well as from references in the sections on reactivity (2.11.3) and synthesis (2.11.4). 

In the first two chapters, the different theories explaining low-dimensional magnetic behavior will be briefly considered and also the available techniques. Then, the most important part (Chap. 3) will deal with fluorinated materials showing low-dimensional magnetism in structures characterized by a 3-D crystallographic arrangement of MF6 octahedra, layers, chains and rings. Spin-flop and zero-point spin-reduction will be also considered, since fluorides provide in these domains most of the conclusive examples. 

Complications within these systems, such as ring spinning and mule spinning, etc., are beyond the scope of this paper, as is any discussion of the eccentricities of the various systems. The systems are designed for a specific purpose and they must accommodate the fiber in question. Manufactured fibers may be cut in proper lengths to be processed on the various systems, and consequently the handling of staple fibers has not been radically changed. 

In principle, this hyperconjugation model (scheme 43) still represents a first-order perturbation it is based on the ESR spectroscopically proven, nearly constant phenyl ring spin population in all related radical cations, i.e. constant squared coefficients c2 (scheme 35), and substitutes the perturbation Sax by the angle-dependent contributions dcx. For a second-order perturbation example, which introduces interactions to additional substituent orbitals (scheme 35), reference is made to the silyl and methyl acetylenes121 (Section IV.E). 

Table 2 Ring Spinning Limits Based on Fiber Length and Fiber Fineness...

The most commonly used method is called core spinning, in which staple fibers are wrapped around a hidden core. It produces chunky novelty yam, although the end weight of the yam depends on the core material used. The elastic fiber is used as core, which is wrapped with other fibers such as nylon, rayon, and cotton. It can be produced on regular ring spinning machines with special feeder rollers and guiding devices (Senthilkumar et ah, 2011). 

Generally, core spun and siro spun methods on regular ring spinning machines are used to produce core spun elastic yam with special feeder rollers and guiding devices. 

Where polymeric fibres are mixed with natural fibres, the continuous multifilaments are cut into lengths according to the mean length of the natural fibres. The fibre-mix is then made into yams via ring spinning, rotor spinning or air-jet spinning. 

Ring spinning is a long established technique used for manufacturing yams from staple fibres such as cotton, flax, wool, etc. The ring spinning system is the most flexible system, and is the most dominant method of yam production when using staple fibres. Several literatures describe its operation and process control. ... 

The ring spinning system involves three basic processes to manufacture a yam from staple fibres. They are ... 

The conventional ring spinning system can be used only with a staple fibre. By slightly modifying the conventional system, it can be used to manufacture hybrid yams, such as core spun yams. - ... 

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. " "... 

Staple fibre aramid yams are produced by reducing a continuous multifilament yam to a bundle of staple fibres by means of steetch breaking and then spinning them into a yam using the ring spinning system. 

Klein W. Manual of textile technology short-staple spinning series, vol. 4, A practical guide to ring spinning. Machester The Textile Institute 1987. 

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