Ring Spinning Process

Sriprateep K and Bohez E L J (2009), A new computer geometric modelling approach of yarn stractures for the conventional ring spinning process , / Text 7nsM00(3), 223-236. 

Batra, S.K., Ghosh, T.K., Zeldman, M.I. (1989b), An integrated approach to dynamic analysis of the ring spinning process. Part II With air drag, Textile Research Journal, 59 (7), pp. 416-424... 

Temperature-dependent lineshape changes were observed in an early study of the fluo-renyllithium(TMEDA) complex. A detailed study by lineshape analysis, which was also applied to the TMEDA complex of 2,3-benzofluorenyllithium(TMEDA) (Figure 29f, yielded barriers AG (298) of 44.4 and 41.9 kJmoD for the 180° ring flip in these systems, respectively . A second dynamic process, which was detected via the temperature dependence of, the spin-lattice relaxation time in the rotating frame, is characterized by barriers of 35.1 and 37.6 kJmoD, respectively, and may be ascribed to the ring inversion process. For the fluorenyl complex, a barrier AG (298) of 15.9 kJmoD for the methyl rotation in the TMEDA hgand was determined from temperature-dependent NMR spectra of the deuteriated system. 

Fig. 14. (a) Solid-state l3C spinning sideband patterns (sum projections) for the aromatic ternary CH in polyphenylene dendrimers, obtained at a spinning frequency of vR = 25 kHz. The spectra were recorded for different temperatures and generations, (b) Corresponding simulated spectra, obtained by taking into account different models of phenyl ring reorientation processes on a microsecond-timescale. For details, see ref. 44. 

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 all cases, because of the orientation phenomenon inherent to the fiber spinning process, the phases are all aligned in the longitudinal direction. In the fibril-matrix structure, the number and size of fibrils depend on composition, rheological properties of the constiments and the type of deformation during spinning. A tree-ring structure , as shown... 

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 ... 

In a ring-spun yam, the number of fibres affected by the twist and the degree of winding influence the mechanical properties and this twist is strongly dependent upon the spinning process parameters. A fully sheath-twisted yam will have a high tensile strength and a lower abrasion resistance. "... 

In the process of yam formation on conventional ring-spinning machines, individual fibres emerging from the nip of the front rollers change their radial position (migrate) until it is fixed by friction between the fibres generated... 

The collected web then was processed on a drawing machine, which uses a series of smooth rollers to draft out the fibers. The residual small pieces of yam and fabric caused the fibers to move as bundles, not as individual fibers. The result was frequent breaks in the sliver. After three passages of drawing, the sliver was entered into a laboratory ring spinning machine. The material processed by this machine was so uneven that it was judged to be unspinnable. 

After carding, the fibers were drawn twice and then ring spun into yam. The spinning process was difficult because the yams frequently broke, as will be seen by comparing these results with those obtained when spinning the 80% new acrylic/20% recycled blend (not chemically treated) described earUer. The spinning performance of chemically treated materials compared to non-treated is shown in Table 10.5. 

The FT-IR spectra of the concerned SMPU fibers are shown in Figs 11.30 and 11.31. The spectra are similar to each other, and only some FT-IR bands of PCL-1% are weaker than others. Band assignments of the FT-IR spectra are shown in Table 11.19. It is expected that the bands at 1410 to 1415cm and 1590 to 1620 cm are identical for all specimens, as these two bands correspond to the benzene ring in the MDI structure, which does not take part in any chemical reaction during the wet-spinning process. 

Since conventional ring spinning systems take several steps to reduce fibers to a spun yarn, several alternative techniques have been developed that reduce the number of these steps. Most of these processes have more limited usefulness with regard to the range of linear densities and type and distribution of fiber lengths that can be processed by these systems,... 

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