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Yarn Manufacturing TECHNOLOGY

Types of Yarn

• Carded Yarn.• Combed Yarn.

Comparison of Combed Yarn & Carded Yarn

Combed Yarn Carded YarnComber is used No Comber is usedLess short fibers More short fibersLess Hairiness More HairinessMore Luster Less Luster

Bale of Fiber Flow Chart For Carded Yarn

Input Process/ Machine OutputBale → Blow room → LapLap → Carding m/c → SliverSliver → Breaker Draw Frame → SliverSliver → Finisher Draw Frame → SliverSliver → Roving Frame

/Speed Frame/Simplex→ Roving

Roving → Ring Frame → Yarn

Flow Chart For Combed Yarn

Input Process/ Machine OutputBale → Blow room → LapLap → Carding m/c → SliverSliver → Pre comb drawing → SliverSliver → Lap former → LapLap → Combing → SliverSliver → Post comb drawing → SliverSliver → Simplex → RovingRoving → Ring Frame → Yarn

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Blow Room

Blow Room is called the mother of yarn manufacturing. It consists of a number of machines used in succession to open and clean the cotton fiber to the required degree.40 to 70% trash is removed in this section.

Blow room line Bale plucker

Opener

Mixer

Step cleaner

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Objects of Blow Room

1. Opening : To open the compressed bales of fibers &To make the cotton tuft a small size as for as

possible.

2. Cleaning :To remove the dirt, dust, broken seeds broken

leafs and other foreign materials from the fibers. More…

Objects of Blow Room

3. Blending & Mixing: To make good value of yarn and to decrease the

production cost by mixing different grade of fibers.

4. Lap forming : To transfer the opened and cleaned fibers into a

sheet form of definite width and uniform unit length which is called lap.

TECHNOLOGICAL POINTS IN BLOW ROOM

Opening in blow room means opening into small flocks

The larger the dirt particle , the better they can be removed

The higher the degree of opening, the higher the degree of cleaning. A very high cleaning effect is almost always purchased at the cost of a high fiber loss. Higher roller speeds give a better cleaning effect but also more stress on the fiber.

Rollers Drums & Beaters Actions involved in Blow Room

1. Action of opposite spike: (opening)By The action of opposite spikes opening the

cotton fiber is done.

2. Action of Air flow: (Transport + Cleaning)During processing, the movement of cotton from

machines to machine is done by air flow. It also helps the separation of lint and trash.

More…

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Cleaning by Air flow Actions involved in Blow Room

3. Action of Beaters: (Cleaning & Opening)Beaters are responsible for removing almost all

of the impurities extracted in the blow room. Beater also helps in opening of cotton fiber.

4. Action of regulating motion: (Uniform output)

The action of regulating motion gives the uniform output.

Cleaning Efficiency

Cleaning efficiency of blow room can be fin out by the following simple calculation.

(Input Trash - Output Trash)*100Input Trash

Problem

Find the Blow Room cleaning effy : Raw cotton trash= 6%Lap trash = 1.6%

Solve: (6-1.6)*100/6=73%

Carding

Carding may be defined as the reduction of an entangled mass of fibers to a filmy web by working between two closely spaced, relatively moving surface closed with sharp wire points.

Objects of Carding

1. Opening to individual fibers.2. Elimination of Impurities and dust.3. Fiber blending.4. Sliver formation.

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Flow diagram of Carding m/c

• A = Cylinder• B = Flat• C = Taker in• D = Feed roller• E = Feed plate• F = Doffer

Actions of Carding m/c

1. Carding Action

This is the action between flat & cylinder.

• Pin direction: Opposite.• Rotation: Opposite.

Actions of Carding m/c

2. Stripping ActionThis is the action between Cylinder - Taker in

• Pin direction: Same.• Rotation: Same.

Actions of Carding m/c

3. Doffing Action

This is the action between Doffer & Cylinder.

• Pin direction: Opposite.• Rotation: Same.

Actions of Carding m/c

4. Combing Action

This is the action between Feed roller & Taker in.

• Pin direction: Same.• Rotation: Same.

Carding Machine

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Carding Machine Draw frame

• It is a process of yarn manufacturing in which the sliver is elongated when passing through pairs of rollers, each pair faster than the previous one.

Actions involved in Draw frame:

Drafting: The process of increasing length per unit weight of sliver. It is mainly due to varying speed of the rollers.

Doubling: The process of combining two or more carded sliver into a single form is called doubling. In draw frame m/c generally six to eight slivers are fed and converted into one.

Drawing = Drafting + Doubling.

TASKS OF DRAW FRAME

• Through draft fibers get parallelized

• Hooked fibers are straightened. • Through the suction ,intensive dust removal is

achieved. • Blending can be done here.

Drawing Machine

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Find out the production/shift in lbs of a modern draw frame, from the following particulars: Delivery speed = 600 m/min, No of delivery/frame = 2, Draft = 8, No of doubling = 8, Feed sliver wt = 0.01 lb/Yd, Efficiency = 90%

Solution:Draft= (Feed wt/Delivery wt)* DoublingSo, Delivery wt= (Feed wt/ Draft)* DoublingSo, Delivery wt= (0.01/8)* 8 = 0.01 lb/yd

Production = 600 m/ min = 600*1.09 yds/min = 654 yds/min= 654*0.01 lbs/min = 6.54 lbs/min = 6.54*60*8 lbs/shift= 3139.2 lbs/shiftFor 90% efficiency and no. of delivery, the ultimate production is, 3139.2*0.9*2 =

5650.56 lb/shift (Ans)

Lap former

• Lap former is the machine where lap is produced from slivers. It is necessary for producing combed yarn. Because the input of comber machine is lap.

Comber

• Combing :

Combing may be defined as to remove short fibers , neps and remaining impurities of card sliver by using comb with the help of knives, brushes and rollers.

Objects of combing

• To remove short fibers below a preselected length so that the spinner enable to produce finer / better yarn.

• To remove neps and foreign matter from the cotton / sliver.

• Make the fiber straight and parallel.

Blow room lap Comber lapShort fiber high Short fibre lowUniformity low Uniformity highTrash high Trash low

Lap count .0011-.0019 Ne Lap count .0075 -.009Lap wt /yds 12-16 ounce Lap wt /yds 1.6-2.5 ounceLap width 1m Lap width 300 mm

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Combing figure

• A= Feed roller• B= Feed plate• C= Nipper• D= Top comb• E= Detaching roller• F= Cylinder

Combing Action

• Firstly, Sliver comes through feed plate, After passing the edge, the nipper comes down to clamp the fiber between feed plate & itself. Then the first combing is done by the cylinder.

Combing Action

• Then, nipper moves upward. Sliver feeding starts again. When sliver comes to detaching roller, the rollers give a backward movement to join it with previously combed sliver. That time Top comb comes down and by the forwarding movement of detaching roller, second time combing is done by top comb.

This process is a intermittent process. Because all these are carried out up to 300 times per minute.

Combing Machine Speed frame

• Task of Speed frame:

• To produce roving from sliver.• To impact strength to the fiber by twisting.• To wind up the resulting roving on to roving

bobbin.

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Speed frame machine Operation involved in Speed Frame

• Creeling: Sliver feeding with the help of several rollers. 40 drawn slivers can be creeled at a time.

• Drafting: To reduce wt per unit length of roving in speed frame so that produces roving can be converted into yarn easily with draft in drafting Zone. For this normally 3 pairs of rollers are used.

Operation involved in Speed Frame

Twisting:

To insert small amount of twist to get required strength of roving . so that no breakage of yarn and possible to wind of roving in convenient package. Usually 30-65 turns per meter twist is given which are created by flyer. But twist in roving are given such that the fibers hold its constituent fibers together and not create hinder during drafting in Ring frame.

Winding:

To wind the roving on to a suitable bobbin which will help handling , transfer and feeding to ring frame. Due to winding , as dia of bobbin is gradually increased, the speed of bobbin is continuously decreased with the help of building motion so that no breakage of roving for too much tension.

• Building : With the help of building motion , the correct or proper shaped package is made by winding of roving on bobbin in some consequent process.

• Doffing : To replace empty bobbin at a place of full bobbin.

Speed frame action

• A= Sliver can• B= Drafting zone• C= Flyer• D= Roving bobbin• E= Gearing

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Sliver & Roving Ring frame

• Ring frame is the machine where yarn is finally produced from the roving.

Function of a Ring frame:

• To satisfy the roving to form yarn of the required count/ fineness of yarn by drafting & twisting.

• To increase strength.• To build up the yarn on to bobbin in form of a

suitable package for storage, transportation and processing.

Operation involved in ring frame

• Creeling• Roving bobbin is fitted on the top of the m/c

on the creel on both sides of the m/c. creel helps to freely rotate of roving bobbin and hold such that roving feed to the drafting zone on tension.

• Drafting• Drafting operation reduces wt per unit length

of roving . roving comes from the bobbin are passed through the drafting.

• Twisting:• Spiral turns are inserted along the fiber axis . It

increases yarn strength .The traveler which helps to insert twisting yarn, gets drive indirectly from spindle.

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Winding:After twisting the yarns are wound on a suitable

package , layers of yarn are wound properly are above another on the package . It should be suitable for unwinding

Building: For proper size and shape of the package the

bobbins are lifted gradually. The resultant bobbins are conical shape full bobbin.

• Doffing: • After the required length of yarn is wound on

the package , the m/c is stopped . Doffing is the process of replacing the full bobbin by an empty bobbin.

Flow diagram of Ring FrameA= Roving bobbin.B= Roving guide.C= Drafting zone.D= Balloon control ring.E= Ring.F= Traveler.G= Yarn bobbin.H= Gearing.

Traveler

• Traveler is the most tiny & important part made by metal through which yarn passes its way from balloon control ring to the yarn package. It has no drive of its own. But it is dragged round by the yarn. During its rotation it produces twist.

Traveler Ring Frame

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Ring Yarn & Rotor Yarn

If there is a simplex machine in the process of yarn manufacturing, that is ring yarn. And if there is no simplex or ring frame, but a rotor spinning machine which converts sliver to yarn directly, the yarn manufactured is a rotor yarn.

Rotor spinning machine Y1 = Ring Yarn & Y2= Rotor Yarn