SPINNING OF WORSTED YARN

Submitted to:Dr. Ashvani GoyalAssistant Professor

Submitted by:Chaitanya Chaudhary(12TT016)Kunal Bansal(12TT036)

Worsted refers to a yarn spun from parallel fibers that have been combed to remove shorter bits and spun with a short draw to keep the fibers in their parallel alignment.

Worsted yarns have more twist inserted which makes them a firmer, stronger yarn. This in turn makes worsted fabrics stronger than woollens

Introduction

These Worsted Spin Yarns have some Special Characteristics from Woolen yarns

Properties

Woolen Yarn Worsted Yarn• Have a short staple (1 - 4

inch long fibers)• Have a long staple length (4

inch fibers and longer only)• Are carded • Are carded and combed• Have a slack twist • Have a tight twist in

spinning• Are weaker • Are stronger• Are coarser • Are finer, smoother• Are bulkier • have more even fibers• Are softer • Are harder

Manufacturing Process

The scouring process of greasy wool includes the following stages Pre-opening, by means of a bale plucker. Fore baled material, or rough opening, by means of an

automatic feeder, when fleeces have already been opened or when fibres are loosened, rough blending of fibres in special blending boxes.

Opening and beating. Scouring, in special scouring vats Pre-drying in the drier Opening and reblending, Final drying, Opening and final reblending

Scouring

The water is homogeneously eliminated from the fibre mass (Figure 106) starting with a first drying (pre-drying) stage .The partially dried mass is then conveyed to a conveyor belt and exposed to the action of automatic feeder, which blends again the layer of fibres fed. The wool is then further dried (final drying) in the second dryer.

Wool is not allowed to dry completely,12-16% moisture left over.

Drying

Pre-dryingIn a three-module dryer, the temperatures in the threedifferent zones can be the following:• approx. 80 °C in the first module,• approx. 120 °C in the second module• approx. 70 °C in the third module,and the dwelling time of the wool inside the dryer should be about 90 seconds

Final DryingThe final dryer is similar to the previous one but includes two modules where temperatures canbe:• approx. 45 °C in the first module,• approx. 65 °C in the second one.The dwelling time of the wool inside the dryer can be approx. 80 seconds

The wool leaving the opener-beater undergoes the so-called oiling. process, which lubricates the fibres by spraying on them an oily emulsion soluble in cold water.

The oil can be used alone or combined with another liquid featuring anti-static characteristics; in this case, the emulsion could be the following:

• 20 - 25 % oil, • 10 - 15 % anti-static product, • 70 - 60 % water to be sprayed on the wool (2- 3 % of the weight of the material to be oiled).

Oiling

Operation is intended to disentangle the fibers and lay them as parallel as possible.

The fibres are passed between rollers covered with fine wire teeth. Since worsted yarns should be smooth, the fibers are made to lie as parallel as this process will permit

Functions of Carding opening of individual fibre elimination of impurities & dust removing of neps fiber orientation sliver formation

Carding

The gilling process removes the shorter staple and straightens the longer fibers.

Gilling is carried out before (preparative gilling) and after (finisher gilling) combing.

The preparative gilling is mainly to align the fibers in a parallel direction, further blend the wool through doubling and to add moisture and lubricants.

Finisher gilling is mainly aimed to remove the mild entanglement introduced to the combed sliver.

Gilling

Combing operation : Removes the shorter fibers of 1 to 4 inch (25 – 100 mm)

lengths (called combing noils). Places the longer fibers (called tops) as parallel as possible. Further cleans the fibers by removing any remaining loose

impurities.

Combing

Combing noils are futher used for ordinary & less expensive fabrics and tops (longer Fibres) for manufacturing owrsted fabrics as gabardine, whip cord & convey & produce fabrics with good color ,feel and strength.

Roving is actually a light twisting operation to hold the thin slubbers intact.

The fiber passes between the roller, over the coarse wire teeth of the first card clothing & over progressively finer toothed card clothing.

The fibre that leaves the machine are in the form of untwisted ropes called “ROVING”.

Roving

In the spinning operation, the wool roving is drawn out and twisted into yarn. There are two main methods used to produce woolen-spun yarns. These are:

Ring spinningMule spinning

Mule-spun yarns generally are superior to ring-spun yarns but they tend to be much more expensive due to the slow production rates and high labor input.

Worsted yarns are spun on any kind of spinning machine – mule, ring, cap, or flyer.

Spinning

The two principle systems of spinning worsted yarns are the English system and the French system :

In the English system (Bradford), the fiber is oiled before combing, and a tight twist is inserted. This produces smoother and finer yarns. The more tightly twisted yarn makes stronger, more durable fabrics.

In the French system, no oil is used. The yarn is given no twist; it is fuzzier, and therefore suitable for soft worsted yarns.

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