Fiber formation spinning speeds

For this comparison, a melt-spinning process was chosen. Each special thermoplastic process influences the structure and thus the properties of the obtained polymer samples differently. This is particularly pronounced for fibers, since especially melt spinning is a process which makes extremely high demands on the deformation ability of the polymer melts at high deformation speeds. Particularly the tensile stress within the fiber formation zone is a very important factor to reach a high orientation of the macromolecules along the fiber axis and a stress-induced crystallization. This crystallization should be discussed in relation to PLA and PHB multifilaments, and at the same time the general property spectrum of these polymers should be represented. 

Shimizu, J., Okui, N. and Kikutani, T Simulation of dynamics and structure formation, in High-Speed Fiber Spinning, Ziabicki, A. and Kawai, H. (Eds), Wiley, New York, 1985, pp. 173-201. 

Fiber spinning is the one area of man-made fiber production in which a major change in technology is most likely to occur in the near future. Ultra high-speed spinning with nonmechanical devices could dramatically affect all phases of pre- and postfiber formation chemistry and technology. 

The latter figure shows the mechanical properties, measured at room temperature, of as-spun poly(l,4-phenylene terephthalamide) fibers plotted against the polymer concentration of the solutions from which the fibers were produced. The draw-down ratio, or spin-stretch factor (wind-up speed/ extrusion rate) was adjusted for each concentration to maintain a constant fiber diameter. Remarkably, these reported results display no discontinuity in the fiber tensile strength or stiffness at the onset of the formation of the anisotropic phase. 

J. Radhakrishnan, H. Ito,T. Kikutani and N. Okui (January 1999), Enhancement of fiber structure formation of a hquid crystalline copolyester via ultra-high speed bicomponent spinning with poly (ethylene terephthalate), Polym. Eng. Sci,39(1), 89-98. 

Giza, E., Ito, H., Kikutani, T., Okui, N. (2000a), Fiber structure formation in high-speed melt spinning of polyamide 6/clay hybrid nanocomposites , J Macromol Sci - Phys, 39 B (4), 545-559. 

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