Factors Affecting The Formation Of Hard Elastic Fibers
Published 1979 · Materials Science
Factors affecting the formation of hard elastic polypropylene and nylon 6,6 are described. In the case of polypropylene, it is shown that the morphology of the stress spin-oriented fibers depends on the molecular weight, the molecular weight distribution, and the cooling rate. Narrow molecular weight distribution and/or fast cooling rate can lead to a smectic, essentially fibrillar morphology in contrast to the normally observed crystalline, essentially lamellar structure. Hard elastic nylon 6,6 fibers are produced by drawing regularly spun nylon 6,6 yarn to draw ratios in the range of 1.6-3 and annealing the resulting fibers in phenol solutions (cone. 1-5 percent). By this method, a highly increased crystalline order is created, simultaneously transforming the original morphology to a lamellare one or superimposing a lamellar morphology on the poorly organized fibrillar base. Some tensile and elastic characteristics of polypropylene and nylon 6,6 yarns as. functions of spinning and annealing variables are presented.