Fiber Spinning

Abstract

Fiber spinning is one of the oldest polymer processing operations that have contributed significantly to our society, especially after the commercialization of polyamide (nylon) synthetic fibers in the 1940s by DuPont Company. Subsequent commercialization of poly(ethylene terephthalate) (PET) and polyacrylonitrile fibers in the 1950s made the synthetic fiber industry very prosperous. For a given fiber-forming polymer, different spinning techniques can produce fibers possessing markedly different physical and/or mechanical properties. Thus, the fiber industry made continuous efforts through the 1960s and 1970s to modify existing processes and develop new ones. One very important breakthrough from such efforts emerged in the late 1970s, enabling one to melt spin at exceedingly high take-up speeds, widely known today as “high-speed melt spinning.” While the fiber manufacturers carefully guarded their spinning techniques, the commercial developments were documented in numerous patents. Beginning in the early 1960s, some fundamental studies on fiber spinning were reported in the open literature, and they are summarized in the three-volume monograph edited by Mark et al. (1967). An understanding of fiber spinning requires knowledge of momentum, energy, and/or mass transport. In addition, knowledge of macromolecular behavior under deformation (i.e., stretching) is also necessary for understanding such complicated problems as molecular orientation under stretching, crystallization kinetics under cooling, and fiber morphology as affected by spinning conditions. In the late 1950s, and the early 1960s, Ziabicki and coworkers (Ziabicki 1959, 1961; Ziabicki and Kedzierska 1959, 1960a, 1960b, 1962a, 1962b) made seminal contributions to a fundamental understanding of fiber-spinning processes, and their efforts were summarized in Ziabicki’s monograph (1976a). In the 1970s, a new class of synthetic fibers, known as “high-modulus wholly aromatic fibers,” was developed (Bair and Morgan 1972; Daniels et al. 1971; Frazer 1972; Kwolek 1971; Logullo 1971; Morgan et al. 1974) and subsequently commercialized with the trade name of Kevlar by DuPont (Kwolek 1971). The chemical structure of such synthetic fibers consists of rigid rodlike molecules that orient easily along the stretching direction during spinning, giving rise to high modulus in the spun fibers. The chemical structure and mechanical properties of the wholly aromatic fibers are well documented in the monograph edited by Black and Preston (1973).