Translation of Fibers and Yarns into Flexible Structures

Abstract

The translation of fibers into 'yarns and these into flexible woven forms has been undertaken, using a number of new and unique organic and inorganic fibers. The stranding and twisting of 0.0005-in.-diameter superalloy filaments has resulted in 'yarn. structures with superior flexibility and strength. The woven fabric of these yarns has 2 to 4 times more strength and 20 to 100 times greater fold endurance than fabrics woven of monofilament wires. The weaving of Beta-diameter fibers of E-glass composition into narrow webbings intended for decelerators has shown that the higher strength retention achieved after pressure and temperature is a function of its finer diameter, even when compared to fibers of S-glass composition. Investigation of the translation characteristics of high-temperature polymeric yarns has been conducted, utiliiing Nomex 1 nylon. The high tninslation efficiencies obtained in weaving this yarn can be attributed to the unique stress-strain hehavior. The comparatively flat shape of the stress-strain curve in the post-yield region explains why little effect of geometry on the fabric strength is visible.In recent years there have been ma'riy advances in fiber research. The need for 'fibers to he transformed into flexible structures has heen supple-' mented by , requirements for high-strength, highmodulus fil~ers to be used as reinforcement in structural and ablative systems. ! The emphasis has , been concentrated on the forming and elyaracterization of fibers regardless of their potential use. In the case of fihers' for flexible structures, it has heen assumed that transformation from fiher to yarn, to . fabric would be a relatively easy and rapid process with no real need for research. Preliminary studies ' . with Nomex (formerly HT-1) Indicated that this ' was a correct assumption. However, as further weaving of this fiber progressed, it became apparent that even this fiber could not be woven into a form that would give mechanical properties equivalent 'to . the nylon form that it was to match, The lower initial strength of the yarn, its susceptibility to highspeed. loading, inability to be dyeg, and poor coating adhesion were only a few of the factors involved,'As a restilt, it became necessary to conduct studies of how the yarn 'structure;' co~strt1ction geometry of a_.__--h ,