26—THE FORM OF YARN TWISTING PART II: EXPERIMENTAL STUDIES

Abstract

Actual and model yams were examined in attempts to observe differences between cylindrical twisting and ribbon-twisting. The model yarn assemblies consisted of elastic threads arranged in various configurations and twisted either in static lengths or in continuous feeding: the position of each thread could be followed. Actual yarns were examined in three ways: as cross-sections, which often showed asymmetry attributed to ribbon-twisting; during untwisting, with the yarn surface coated; and after twisting of rovings, spun yarns, and continuous-filament yarns in ways designed to bring about cylindrical twisting and ribbon-twisting. The tendency of fibres from one side of a ribbon to go into the centre of a yarn was demonstrated.