3 - Fundamental principles of open end yarn spinning

Abstract

Open end spinning has several advantages over ring spinning, such as increased production rate, separation of twisting and winding, possibilities of full automation of yarn spinning, and elimination of speed frame and winding. Rotor spinning, friction spinning and vortex spinning systems are three major methods of yarn manufacture developed on the principle of open end spinning. Rotor spun yarns have a different structure: a densely packed core of fibres substantially aligned with the yarn axis; loosely packed fibres twisted around the core at a considerable angle to the axis; and wrapper fibres on the outside. Due to this type of structure, open end (OE) spun yarns are successful in the commercial manufacture of coarser yarns. The structure of friction spun yarn is determined by the way fibres are assembled into the yarn. The structures of OE-friction spun yarn and core-type friction spun yarns are different. The internal structure of open end friction spun yarn is characterized by the inferior fibre orientation, buckled and folded fibre configurations and loose packing of fibres associated with low tensions during yarn formation. Vortex yarn has a fasciated yarn structure. The yarn has a two-part structure: core and wrapper fibres. The parallel core fibres are wrapped by the surface fibres to impart strength. The principle and methods of manufacturing of these open end spun yarns, their properties and end uses are discussed in detail.