NEW SPINNING SYSTEMS Why New Spinning System Because

NEW SPINNING SYSTEMS

Why New Spinning System? Because, Ring-spinning has reached its limits When spinning, the spinning bobbin has to make a full turn to twist the yarn once, and this is the real reason for the limits to higher production rates on ring-spinning machines. Due to the fact that supply of fibers to a ringspinning machine has to be in the form of rovings instead of slivers, and, because the small spinning bobbins produced have to be rewound, ringspinning is somewhat ill-suited for automation

Classification of new spinning systems: • Open-end Spinning Systems: Rotor spinning, Friction spinning, Air vortex spinning (MVS) • Wrapped Spinning Systems: Air-jet spinning (MJS), Hollow-spindle spinning • Self-twist Spinning • Compact Spinning and Solo Spinning (developed on the base of conventional Ring spinning)

Open-end spinning • It is a process in which fibrous material is highly drafted, ideally to the individual fiber state, creating a break in the continuum of the fiber mass. The individual fibers are subsequently collected onto the open end of yarn that is rotated to twist the fibers into the yarn structure to form a continuous yarn length. The length of yarn spun is then wound to form a package. Thus, the twisting action occurs simultaneously but separately from winding.

Rotor Spinning • 2 feed roller, 3 feed plate, 5 opening roller, 8 fiber transport channel, 18 rotor, 17 delivery rollers

Process of Rotor Spinning • The sliver must be reduced to an almost single-fiber stream before it is caught up in the open end of the yarn. The opening roll separates fibers from the incoming sliver. A high-speed air stream is used to remove the fibers from the roll and transport them through a fiber transport channel to the rotor. • The drafted fiber is deposited as a very thin continuous stream into a V-shaped collecting groove inside the rotating rotor. With each revolution of the rotor, additional fiber builds up and twist is added to the assembled fibers at a rate of about one turn of twist per revolution. The winding of the yarn package is a separate function that does not affect the twist level in the yarn.

Features of Rotor Spinning • Yarn properties: lower tensile strength than ring yarns; good uniformity and cleanliness • Application: for woven, warpknit and knitted materials • Advantages: low manufacturing cost; fully automated • Limitations: not the same range of application possibilities as ring-yarns

Air-jet spinning (MJS)

Process of Air-jet Spinning: • After passed a drafting zone, the fiber strand passes a device with two nozzles. A counterclockwise vortex is set up in jet 1 to give a Z false-twisting action, and a clockwise vortex in jet 2 gives an S false twist. As the pressure of jet 2 is larger than that of jet 1, it enables S twist from jet 2 to propagate along the false-twisted core and null the Z twist of jet 1, leaving some S-twist to travel toward the nip line of the front rollers. • In jet 1, the edge fibers wrap the false twisted core by the swirling air currents. • Therefore, untwisting downstream of jet 2 produces considerably more twist in wrapper fibers, giving the yarn its strength.

Murata Air-Jet Spinning System

Features of Air-jet Spinning • Yarn properties: somewhat lower tensile strength; slight hairiness; somewhat rougher surface • Application: dressmaterials; home furnishings; bed sheeting • Advantages: low manufacturing cost; high production rate; no fast-moving parts • Limitation: not suitable for cotton

Friction Spinning (Drefspinning)

Friction Spinning (Drefspinning) • After passing the card drum the fibers are transported by air to a friction zone, where two drums rotating in the same direction insert the twist by frictional rolling of the yarn tail while simultaneously twisting fibers onto the yarn tail. At each turn of the yarn end the yarn is given one turn of true twist.

Features of friction-spinning • Yarn properties: low tensile strength; • good uniformity • Application: yarns for knitting; terry yarns; weft yarns • Advantages: low manufacturing cost; possibility for automation; no fast-moving parts • Features: up now no limited application possibilities; delivery speed is independent from yarn count

Suessen Compact Spinning