Yarn windingByM. Naveed Akhtar

Yarn Winding- Past and PresentIn the past winding of yarn was considered as

SimpleUnimportantNon-productive process

Now it is considered important because itGives opportunity for faults removalGives opportunity to carry out yarn

conditioning, yarn waxing etcEnsures increased processing efficiency of

subsequent processes

Types of Winding PackagesFor single and plied yarns

Parallel-sided cheeseCone

For sewing threads and synthetic filament yarnsParallel-sided cheeseSpool

Parallel-Sided Cheese

A Spool

A Cone

Parallel sided CheeseThe winding and withdrawal of yarn are at

constant speedThe package can be unwound either by side

withdrawal and package rotation, or by over-end withdrawal

Side WithdrawalPackage rotates while unwindingThe yarn unwinding speed will be limitedNo change of twist during unwinding

Parallel sided CheeseOver-end Withdrawal

Unwinding without package rotationsChances of sloughing off fault of yarn due to

yarn/package frictionDuring unwinding the twist in yarn is changed

(either increased or decreased) by an amount equal to 1/πD where D is package diameter

Hence all the packages should be placed same way up so that unwinding is done in one direction of rotation only

Wind and traverse ratioThe Wind is the number of coils of yarn

wound on per single traverse from one end of the package to the other

The Traverse Ratio is the number of coils of yarn wound on per complete traverse cycle

The traverse ratio is twice the wind

A ConeA cone is a more stable package compared to

cheeseSloughing off does not occur during handling and

unwinding due to minimum yarn/package frictionCones are unwound over-end without package

rotationThey give low and relatively uniform unwinding

tension at high speedsHigh speed winding can be done at about 1400

m/minA twist is inserted (or removed) in the yarn for

each revolution of yarn withdrawn

A ConeLonger length of yarn can be obtained on

cones as compared to cheesesThis increases the productivity of subsequent

processesCones can be made larger than cheesesUsually cones can be made up-to 2 kg

package mass, but larger cones of up-to 5 kg can be made for carpet yarns

Cone taperThe cone taper is the

semi-vertical angle, i.e. between the cone axis and its sloping face

Types of Winding MachinesPrecision windingDrum winding or random windingPrecision Winding

The package is mounted on a spindle which is driven with the help of an individual motor

Yarn passes through reciprocating yarn guides which are driven by a cam shaft

There is no slippage in the device or uncontrolled displacement of the yarn, therefore it is called precision winding.

The ratio between the spindle speed and the traverse speed is precise

Types of Winding MachinesSpeed of conventional precision winder is

limited by traverse speed of yarn guideTo overcome it a grooved traverse roller is

used to reciprocate yarnNow speeds of more than 1500 m/min have

been achievedSewing threads are usually precision wound on

cones, cheeses and spoolDrum Winding

Package is driven by surface contact with a motor driven drum

Drum Winding

Types of Winding MachinesSpeed of drum decreases as the package diameter

increasesThe mean yarn speed is approximately constantThis results in uniform application of lubricantsAs package diameter increases its angular velocity

decreasesThe fault of patterning or ribboning occurs in

drum windingYarn would return to exactly the same starting

pointThe next set of coils are laid on top of previous

onesAt yarn breakage the drum winding unit is stopped

to allow for yarn knotting or splicing

Yarn tensioningOlder machines used dead-weight loading over two

discs between which yarn passedMost modern machines use disc tensioning devicesYarn is drawn between two discs which have

adjustable spring loading to apply required tensionWinding tension causes weak places in yarn to

breakThis results in less stoppages in subsequent

processesToo high winding tension results in very hard

package but elastic properties of yarn will be affected

Length measuring systemThe modern machines are equipped with

good length measuring systems to control the package weight variation

The uniform package weight helps in reducing the losses weight variation in dyeing and also reduce the chances of excess dyeing and short falls

Balloon breakersThe modern machines are fitted with an

adequate balloon breaking device, which provides more flexibility to use different size of feed packages and also reduce the breakages rate

Yarn KnottingIn older

machines knotting was done

It was done either by hand or by means of mechanical knotters

Most common knots used are dog knot, fisherman’s (back-to-back) knot and weaver’s knot

Yarn Splicing

Yarn SplicingIt is the joining of yarn without knottingTwo broken ends of yarn are held and cut at

splicing pointThese ends are inserted in an air vortex tubeIt untwists the two yarns and extracts loose

fibres to taper themThese two ends are then drawn back until

correct length overlaps each otherA jet of turbulent air intertwines the fibres

from two ends to form a splice

Yarn SplicingThe twist of adjacent areas rushes to cover

the joining areaHence the twist per inch at splice is less than

original yarnThis results in reduced yarn strength at

spliceThe yarn diameter at splice is nearly the

same, hence it is not visible in the fabric

Yarn ClearingYarn faults cause 10% stoppages in warping,

20% in weavingMending is un-economical for cotton-spun

materialsIt is technically impractical in most knitted

fabricsHence fault removal at the winding stage is

desirableInitially mechanical yarn clearers were usedNow electronic yarn clearers are in use

Photoelectric clearersCapacitance clearersDual clearers (e.g. Uster Quantum Series)

Yarn Clearer by LOEPFE

- Count Channel

- Neps

- Short Thicks

- Long Thicks

- Long Thins

- Hairiness

Spinning Yarn Faults

- Contamination

Yarn Faults Removal

Foreign Matter Dark (FD) Channel

Dark and Light

Coloured

Contaminations