NEW SPINNING SYSTEMS

Hafeezullah MemonZSTU, hangzhou, China

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 ring-spinning machine has to be in the form of rovings instead of slivers, and, because the small spinning bobbins produced have to be rewound, ring-spinning is somewhat ill-suited for automation

Why New Spinning System?

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)

With regard to yarn production, the following features are always relevant:

• Reducing the fiber count in the cross section of the supply material corresponding to the required yarn denier

• to impart the necessary strength to the resultant fiber assemblage

• to wind-up the yarn

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.

With regard to the conversion of the supply materials into a denier-correct fiber assemblage, there are two systems:

• drawing system

• opening roll with fiber transport channel: there is a break between opening of the supply material to a yarn–the principle of open-end spinning.

With regard to the consolidation of the fiber assemblage, there are two systems:

• real twist: is imparted with ring spinning and OE spinning.

• false twist: is imparted with wrapped spinning

Rotor Spinning

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

Rotor Spinning

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

Air-vortex Spinning (MVS)

Air-vortex Spinning (MVS)

• The leading ends of the fiber bundle are drawn into the hollow spindle by the fibers of the preceding portion of the fiber bundle being twisted into a spun yarn. The trailing ends of the fibers are inverted at the inlet, separated from each other, and exposed to the swirling air blown through the nozzles. The trailing ends of the fibers are thereby caused to twist around the porting of the fiber bundle being converted into a spun yarn.

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

Compact and Solo Spinning

Spinning triangle in Ring SpinningIn Compact Spinning, the drafted ribbon is condensed

Solo Spinning

Compact and Solo Spinning

• These two systems are essentially modifications to the conventional ring spinning process with the aim of altering the geometry of the spinning triangle so as to improve the structure of the ring-spun yarn by more effective binding-in of surface fibers into the body of the yarn. This reduces yarn hairiness.

Suessen Compact Spinning

Suessen Compact Spinning

Suessen Compact Spinning