Presentation Shrinkage

7/27/2019 Presentation Shrinkage

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Project report prepared by,

FAISAL AHMED

ROLL NO.070023


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Bangladeshi knitwear is exported to over 100 countries of the world andhas passed the target of US$ 5.5 billion mark in its exports this fiscal year.Bangladesh is now the number three exporter of knitwear to the EUcountries after China and Turkey and is gaining momentum due to itsself-sufficiency and competitive workforce and strength in backward linkage.Over a period of time the knitwear sector has gradually become almostself sufficient in fabric and yarn and this improvement has becomepossible because of the integrated growth of spinning factories in linewith the growth of country's stitching capacity and increased need foryarn and fabrics.As the exports have increased in the knitwear sector, the capacity ofbackward linkage has also gradually increased accordingly. The result isthat local suppliers can provide 90% of the total fabric requirement of the

sector. The growth of spinning mills has also been in step with the growthof knitwear exports. In 1993-94 the total number of spindles was 1.38million that supplied 10.70 million Kg of yarn. In 2003-04 the numberalmost tripled to 3.77 million, which supply 239.00 million Kg of yarn. Todate, the total investment in the backward linkage industry is more thanUS$ 2.00 billion. Bangladeshs knitwear industry is growing at over 15%per annum.


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Spirality is a common problem in weft knitted fabric. It is the de-twisting tendency of yarn in the fabric. It appears in mostly insingle jersey fabrics but in double jersey fabrics this level inabout zero. The causes of formation of spirality in twistness inthe yarn and increase it by using more number of needles andmultifeeders machine so on. It can reduce in different ways butnot remove from the fabrics.

Shrinkage is the dimensional change in length and width wise inthe fabric. It mainly occurs for swelling of yarn. So, it appearsmore in cotton fabrics than synthetic fabrics. It can reduce theshrinkage by using stenter machine after dyeing and drying thefabric. Also, if the higher GSM/lower stitches length/lower twistfabric contains lower shrinkage of fabric.

For measuring the spirality and shrinkage at first we have doneISO-6330 washing then use ISO: 16322-2 for spirality and ISO-5077 for shrinkage. And these are international standard ofthese measuring systems.


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Shrinkage: A dimensional change resulting in a decrease in the length or width ofspecimen subjected to specified condition is known shrinkage.

Spirality: If the wales of the knitted fabric are not perpendicular to the course andskew to the right or left Spirality occurs in the fabric. This creates serious problem,especially in the apparel industry.

Yarn twist: Twist is the measures of the spiral turns given to a yarn in order to hold theconstituent fibers or threads together. Amount twist i.e.TPI greatly influenced the

fabric Spirality.Twist liveliness: The tendency of a yarn is to twist or untwist spontaneously. The

direction of twist liveliness or torque S or Z twist change that takes placespontaneously when an end or hanging loop is allowed to rotate freely. Higheramount of twist leads high liveliness and creates fabric Spirality.

Dry Relaxed State: The fabric moves to this state with time. The dry relaxed is restrictedby fabric structure and fiber type. Only wool can attain this state.

Wet Relaxed State: Static soak in water and dry flat. This state tight structure doesnt

always reach a true relaxed state. Only wool and silk can attain this state. Soakwater with agitation or agitation in steam or static soak at selected temperature(below 900C)


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RAW MATERIAL OF APS APPARALS LTD.

Knitting Section

Yarn Purchase

Nature Cotton

Combed 16/s , 18/s, 20/s, 24/s, 26/s, 28/s , 30/s, 32/s, 34/s, 40/s, 42/s, 44/s,

Carded 20/s , 24/s, 24/s (slub), 26/s, 26/s (slub), 28/s , 28/s (slub), 30/s, 30/s (slub), 34/s (slub), 42/s,

44/s.

Synthetic Polyester 150/D, Viscose 40/s, 38/s PC & CVC Yarn

PC (10/s , 20/s, 24/s, 26/s, 30/s, 34/s )

CVC ( 60:40) (20/s , 24/s, 26/s, 28/s, 30/s, 34/s , 40/s,)

CVC (80:20) (30/s, 40/s )

Milange Yarn

Grey milange 15% (10/s, 30/s,) Grey milange 5% (20/s , 26/s, 28/s, 30/s, 34/s, 40/s)

Grey milange 10% (20/s , 24/s, 26/s, 28/s, 30/s, 34/s,40/s )

Eco milange 2%, (20/s, 24/s, 26/s, 28/s , 30/s,)

Eco milange 1% (20/s , 30/s, 26/s)

Lycra 20/D,40/D,70/D

Modal ( 50%+50%) (28/s, 30/s, 34/s , 40/s,)


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RAW MATERIAL OF APS APPARALS LTD.

Source of cotton yarn

Local Imported

PrimeWinsome

YouthG.T.N

Nahid NZ Textile Shirin Acetone

Techno Sudan

Chandra Texlong

Bengal NFK Rajastan

Mondal Indosome

Otto

Metro Badsha

Shah Fatulla


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Spirality is a dimensional distortion in circular

plain knitted fabrics. The wales or needle lines,should occupy a truly vertical line in the fabricand should always be right angles to the crosswise courses of stitches.

This perpendicularity of wales to the courses is

frequently, not the case and many times thewales may skew to the right or left forming anangle, which appears in the form of a twilledsurface.


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SHRINKAGE

A dimensional change resulting in a decrease in the lengthor width of a specimen subjected to specified conditions isknown shrinkage.

Reduction in length and width of fabric induced by

conditioning, wetting, steaming, chemical treatment, wetprocessing as in laundering, in chemical practice and inliterature the following terms have been used to describethe shrinkage which occurs in testing procedure:

Relaxation shrinkage,

Felting shrinkage, Compressive shrinkage,

Residual shrinkage.


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CAUSES OF SPIRALITY:

The residual torque or twist liveness.

Count of yarn,

Fabric structure,

GSM Fabric Relaxation,

No. of feeder.

Twist direction,

Machine rotation,

Spinning system,

Fabric finishing.


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Average deflection length from the seam line = X Y= Sample length, Spirality% =

Example: Average deflection, X = 2cm Sample length, Y = 50cm Spirality% =

As per the experience of world renowned retailers inthe globe, seam twisting / shape distortion / spiralitygreater than 6% in tops and shorts and 4% in skirts,

pants, dresses, and sleepwear detracts from theappearance of the garment.


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RELATION BETWEEN GSM & SPIRALITY% (TUMBLE DRY)

0

1

2

3

4

5

6

120 GSM 130 GSM 140 GSM 160 GSM 180 GSM

Spirality(%)

Single Jersey Fabric GSM (Cotton)


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Relation between GSM & Shrinkage% (Tumble Dry)

-8

-7

-6

-5

-4

-3

-2

-1

0

120 GSM 130GSM 140 GSM 160 GSM 180GSM

sh

r

i

n

k

a

g

e(

%)

i

n

W

i

d

t

h

w

i

s

e

single jersey fabric GSM(Cotton)


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0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5


Spirality(%)



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-8

-7

-6

-5

-4

-3

-2

-1

0


s

h

r

i

nk

a

g

e(

%)

i

n

W

i

d

t

h

w

i

s

e

single jersey fabric GSM(Cotton)


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0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5


Spirality(%)



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0

0.5

1

1.5

2

2.5

3

3.5

4


Spirality(%)



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-6

-5

-4

-3

-2

-1

0


s

h

r

i

n

k

a

g

e

%

i

n

W

i

d

t

h

w

i

s

e

single jersey farbic GSM (Cotton)


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0

0.5

1

1.5

2

2.5

3

3.5

120 GSM (Tumble Dry) 120 GSM (Hang Dry) 120 GSM (Flat Dry)

Spirality(%)

Single Jersey Fabric GSM (polyester)


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RELATION BETWEEN GSM & SHRINKAGE% FOR

POLYESTER YARN IN DIFFERENT DRY CONDITIONS.

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

Tumble Dry(120 GSM) Hang Dry (120GSM) Flat Dry (120GSM)

s

h

r

i

n

ka

g

e

%

i

n

W

i

dt

h

w

i

s

e

single jersey fabric GSM (Polyester)


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RELATION BETWEEN GSM & SHRINKAGE% OF DIFFERENT TYPES

OF FABRICS (TUMBLE DRY)

-6

-5

-4

-3

-2

-1

0

1

2

PK(22O GSM) 1*1 Rib(220GSM) Interlock (220GSM)

s

h

r

i

n

k

a

g

e

%

i

n

W

i

d

t

h

w

i

s

e


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In finishing section fabric GSM, Spirality and shrinkage beingcontrolled in various finishing machine such as squeezer, dryer,open & tube compactor and stenter.

Some descriptions are given below: Squeezer:

Textile materials such as knitted fabrics are usually extended inlength wise direction due to tension specially in dyeing process.When the dyed fabrics are passed through the squeezer dia of thefabric can be controlled by adjusting the width of the spreaderframe by controlling width wise shrinkage. Squeezer machinehelps to remove water from the fabric.

Specification: Name: squeezer machine. Brand: SANTAX Origin: Switzerland. Data: Squeezer


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Fabric type Color GSM Machine speed Over feed Dia Dia+

Single jersey Navy 180 20 +30% 60 +4

Single jersey Dark red 160 20 25% 60 +4

Single Lacoste Sky blue 150 20 20% 69 +4

Double lacoste Avg(wood) 180 20 25% 66 +4

Interlock black 210 20 18% 108 +5

Flat back rib black 340 20 15% 75 +5


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Fabric type Color GSM Line speed Compaction% diaSingle jersey Navy 180 40 8% +4Single jersey Dark red 160 40 6% +3Single Lacoste Sky blue 150 25 8% +3Double lacoste Avg(wood) 180 40 18% +5Interlock black 210 40 15% +8Flat back rib black 340 40 15% +2


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Fabric type Color GSM Required dia Finished dia Finished GSM Shrinkage inlength wise Shrinkage inwidth wise

Single jersey Navy 180 60 61 178 -5% -4%Single jersey Dark red 160 60 61 155 -4% -2%Single Lacoste Sky blue 150 69 68 147 -3% -7%

Double lacoste Avg(wood)

180

66

63

165

-7%

-9%

Interlock black 210 108 109 210 -2% -4%Flat back rib black 340 75 75 345 -4% -3%


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CONCLUSION

In general the angle of spirality values are decreasing, when thetightness factor values are getting tight in the all knitted fabric samples.In slack knitted fabric structures, the loop can easily find area to rotateso spirality is increasing.

The spirality angle of the fabrics knitted with ring yarns are very high

comparing with the fabrics knitted with open-end yarns. This shows theeffect of the spiraled on twist liveliness. Because the twist liveliness ofthe ring yarns used in producing single jersey fabric is higher than theopen-end yarns used in producing single jersey fabrics.

Fabrics shrinkage depends on different fabric structure i.e; single jersey,rib, interlock and their derivatives. Yarn composition i.e; 100% cottonand polyester and synthetic yarn.

More research and development is required to control the fabricspecifications accurately. We could not able to execute the project workperfectly for limitations of time and lack of opportunity to examine thevarious tests in the factory.

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Presentation Shrinkage