Fiber spinning speeds

Tensile Properties. Tensile properties of nylon-6 and nylon-6,6 yams shown in Table 1 are a function of polymer molecular weight, fiber spinning speed, quenching rate, and draw ratio. The degree of crystallinity and crystal and amorphous orientation obtained by modifying elements of the melt-spinning process have been related to the tenacity of nylon fiber (23,27). 

Polyester (or other fibers such as nylon or polypropylene) staple fibers can be produced by either a one-step process or a two-step process. The process steps are the same in both cases however, the fiber spinning speed is lower in a one-step process and the fiber is drawn, crimped and heat-set in one continuous machine. These one-step lines generally have smaller capacities and are often fed by extruders. They are mostly used for specialty fibers, such as bicomponents and non-apparel end uses and nonwovens. 

Flow processes iaside the spinneret are governed by shear viscosity and shear rate. PET is a non-Newtonian elastic fluid. Spinning filament tension and molecular orientation depend on polymer temperature and viscosity, spinneret capillary diameter and length, spin speed, rate of filament cooling, inertia, and air drag (69,70). These variables combine to attenuate the fiber and orient and sometimes crystallize the molecular chains (71). 

A. Ziabicki and H. Kawai, eds.. High Speed Fiber Spinning ohm. Wiley Sons, Inc., New York, 1985. 

Fig. 11. Effect of spinning speed on properties of nylon-6 fibers, where (T) is the tangent modulus (° ), the tenacity and (A ), the elongation. To convert...

Figure 12.8 Typical forces acting upon a spinning threadline [8]. From Ziabicki, A. and Kawai, H., High Speed Fiber Spinning - Science and Engineering Aspects, 1991, and reproduced by permission of Krieger, Malabar, FL...

Figure 12.9 Effect of spinning speed on fiber orientation and shrinkage [14]. From Brunnschweiler, D. and Hearle, J. (Eds), Polyester - 50 Years of Achievement, 1993, p. 193, and reproduced by permission of The Textile Institute, Manchester, UK...

Table 13.1 Intrinsic viscosity and molecular weight data for the three characterized polymers (cf. Figure 13.2) [13]. From Some effects of the rheological properties of PET on spinning line profile and structure developed in high-speed spinning , Perez, G., in High-Speed Fiber Spinning, Ziabicki, A. and Kawai, H. (Eds), 1985, pp. 333-362, copyright (1985 John Wiley Sons, Inc.). Reprinted by permission of John Wiley Sons, Inc.

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. 

---