Project report

PROJECT WORK

ON

.

Supervised by

A.K.M FARIDUL AZADHEAD OF THE FABRIC MANUFACTURING DEPARTMENT

PABNA TEXTILE ENGINEERING COLLEGE SHALGARIA,PABNA-6600

Presented by

MD. EKRAMUL HASAN ROLL NO. :070065 REG. NO. :4534 SESSION. :2006-2007

CONTENTS OF THE PROJECT

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CHAPTER INDEX

PAGE NO.

CHAPTER-1 ACKNOWLEDGEMENT 3

CHAPTER-2 TITLE OF THE PROJECT 4

CHAPTER-3 PROJECT ABSTRACT 5

CHAPTER-4 INTRODUCTION 6-8

CHAPTER-5 RAW MATERIALS 09-10

CHAPTER-6 MARKETING 11-12

CHAPTER-7 IMPORTANCE OF THIS SURVEY 13

CHAPTER-8 TERMINOLOGY DEFINATION OF SPIRALITY & SHRINKAGE

14-16

CHAPTER-9 GEOMETRY OF SPIRALITY & SHRINKAGE 17-23

CHAPTER-10 CAUSES OF SPIRALITY & SHRINKAGE 24

CHAPTER-11 METHODS TO MINIMISE THE PROBLEMS 25

CHAPTER-12 PROBLEM ASSOCIATED WITH SPIRALITY & SHRINKAGE 26

CHAPTER-13 CONCLUSION 27

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At first I would like to express my heart-felt thanks to Almighty ALLAH for his kind blessing to

complete the Industrial training & this report successfully. I would like to thanks the people, who

have made a significant contribution to make this report. Their guide lines, suggestions &

inspiration helped me a lot.

I would like to express my deepest appreciation, sincerest gratuity to our respected Sir A.K.M

Faridul Azad, Chief instructer, Fabric Manufacturing Department, my supervisor, for his

tremendous support and guidance throughout my training period. Being working with her I have

not only earned valuable knowledge but was also inspired by his innovativeness which helped

enrich my experience to a greater extent. Her ideas and way of working was truly remarkable.

I also express my gratitude to Abdul Based , Principal, Pabna Textile Engineering college, for his

support and continuous guidance throughout my long journey in the industrial training.

I would like to thank the management of “Padma PolyCotton Knit Fabrics Ltd."for giving me the

opportunity to do the industrial training successfully and also their valuable suggestions. My

deepest appreciation goes to Khalid Hossain Khan, Director Production of Padma PolyCotton

Knit Fabrics Ltd. for his permission to conduct my industrial training without which it would be

uncompleted. The generous support is greatly appreciated. I would also like to thanks executives,

senior executives and other officials of Padma PolyCotton Knit Fabrics Ltd.for helping me to

complete industrial training successfully. My gratitude also goes to all the employees Padma

PolyCotton Knit Fabrics Ltd.for their sincere co-operation, support and valuable advices.

Last but not least, thanks go to my precious family for their never ending love and inspire at every

stages of my life. Without their continuous support I realize that I would not be a person I am right

now.

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Spirility and Shrinkage problems in knitting industry and means to minimize it .

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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 in single jersey fabrics but in double jersey fabrics this level in about zero. The causes of formation of spirality in twistness in the yarn and increase it by using more number of needles and multifeeders machine so on. It can reduce in different ways but not remove from the fabrics. Shrinkage is the dimensional change in length and width wise in the fabric. It mainly occurs for swelling of yarn. So, it appears more in cotton fabrics than synthetic fabrics. It can reduce the shrinkage by using stenter machine after dyeing and drying the fabric. Also, if the higher GSM/lower stitches length/lower twist fabric contains lower shrinkage of fabric. For measuring the spirality and shrinkage at first we have done ISO-6330 washing then use ISO: 16322-2 for spirality and ISO-5077 for shrinkage. And these are international standard of these measuring systems.

Evolution of Knitting Industries In Bangladesh:

Bangladesh had a historical reputation in production of textile products in addition tofamous Dhaka muslin. Fabrics from Bengal were found in ancient Egyptian tombs, and weretraded with the Roman and Chinese empires in the medieval age. In ancient Bengal a greatdeal of expertise existed with regards to weaving of textile products as well as great

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reverence towards its trade. In rural communities both men and women were apprenticed inweaving. These skills and disciplines in sewing and weaving are passed down throughgenerations and are quickly transferred to production lines in modern knitwear factories.In the early 1980s, there were small-scale independent investments in the readymadegarments (RMG) sector. At that time, it was not considered viable and received very littlegovernment attention. Within a decade, the RMG industry in Bangladesh had flourished andby the early 1990s it had emerged as a major employer. Under the dynamic leadership of theprivate sector together with policy support from the government, the export oriented RMGindustry has shown a spectacular growth during the last two and a half decades. The textilesector initially could not keep pace with the requirement of yarn and fabrics particularly bythe woven RMG sector as the textile and clothing industry was controlled by a fairly smallcommunity of local entrepreneurs. However, the sector grew with vengeance and the countrycurrently exports over US$11 billion in textiles and garments, with a projected target ofUS$24 billion dollars by 2020.

Evolution of Knitwear Exports

The RMG business was initiated with the export of knitwear consignment in 1973.Eventually the RMG sector accelerated exports dominated by woven garments. The knitwearsector’s significant contribution in country’s export share was 1.1% in FY 82. Since then itgradually increased its share in exports. While the contribution of woven garments to the4export basket was 42.8% in FY 91, the knitwear sector’s contribution rose to 7.6%. Table 1presents export performance and the extent of retention rate due to high contents of domesticinputs. In FY 04, knitwear sector for the first time exceeded woven sector and became theleader with an exported quantity of 91.6 million dozens. The sector continues to be the leaderin terms of quantity exported with an increasing gap with the woven garments over time.Export quantity of knitwear items increased to 241.59 million dozens. This is roughly equalto 163.7% growth between FY 04 and FY 08. At present knitwear is the largest exportearning sector of Bangladesh contributing 41.8% to national export earnings at the end of FY09 (July-April).

Total Knitwear Exports and Net Retention in Bangladesh:

Exports (US $million)

Share of NetRetention

Share of

Year TotalRMG

Knitwear Knitwear(%)

(US $million)

NetRetention(%)

1994-95 1850.3 393.3 21.3 157.3 401995-96 2006.6 598.3 29.8 253.7 42.4

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1996-97 2316.9 763.3 33.0 335.9 44.0

1997-98 2775.4 940.3 33.9 443.8 47.2

1998-99 2700.0 1035.4 38.4 530.1 51.2

1999-00 3125.4 1269.8 40.6 695.9 54.8

2000-01 3755.6 1496.2 39.8 837.9 56.0

2001-02 3355.4 1459.2 43.5 826.9 56.7

2002-03 3601.4 1653.8 45.9 965.8 58.4

2003-04 4443.3 2148.0 48.3 1271.6 59.22004-05 5429.7 2819.5 51.9 1691.7 60.0

2005-06 6041.9 3817.0 63.2 2290.2 60.0

2006-07 7517.2 4553.6 60.6 2732.2 60.0

2007-08 8322.2 5532.5 66.5 3319.5 60.0

Source: Bangladesh Bank and BKMEA Website

Bangladeshi RMG products are mainly destined to the US and the EU markets. Withtheir earnest efforts from late 1980s the RMG exporters were able to export US$ 393.26million in FY 95. Of this amount, the shares of the EU and the USA were US$ 274 millionand US$ 98 million respectively. During FY 97, Bangladesh was the 7th and the 5th largestapparel exporter to the US and EU markets respectively. The cumulative average growth rateof the sector is about 20%. In recent years the EU market was the main export market for5Bangladeshi knitwear constituting 76% (US$ 4.2 billion) of total knitwear export followed bythe USA (14.59%, i.e. US$ 807 million) in the year FY 08. The impressive growth of theknitwear in the EU market was partly due the market access opportunities provided under theGeneralized Systems of Preference (GSP) facility. Further, the two-stage transformationrequirement of the rules of origin (ROO) introduced in 1999 accelerated market penetration.

Social Impact:The major strength of the Bangladesh textile industry is the pool of motivatedworkers. The sector has created jobs for about 2.5 million people (Table 4) of which 70% arewomen originating mostly from rural areas. Due to a liberal cultural attitude towards womenin the workforce, the RMG sector has transformed a traditionally male dominated society toone where women have an equal status as earners in the household (see Zohir and Majumder,1996). The number of factories in the RMG sector increased in tandem from less than athousand in FY 91 to about five thousands in FY 08. Competitive wage rate together witheasily trainable workforce helps transform the comparative advantages into copetitiveadvantage in this sector. Directly employed labor force in the knitwear sector are 1 millionand another 0.5 millions are indirectly employed.

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Number of Establishments, Employment, and Firm Size in the Knitwear Sector

Year Number of Establishments

Employment (in million)

Employment per Firm

1994-95 2182 1.20 550

1995-96 2353 1.29 548

1996-97 2503 1.30 519

1997-98 2726 1.50 550

1998-99 2963 1.50 506

1999-00 3200 1.60 500

2000-01 3480 1.80 517

2001-02 3618 1.80 498

2002-03 3760 2.00 532

2003-04 3957 2.00 505

2004-05 4107 2.10 511

2005-06 4220 2.20 521

2006-07 4490 2.40 535

2007-08 4740 2.50 527

2.1 Types of raw material

Yarn: Carded YarnCombed Yarn

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Cotton + ModalCotton + Viscose

Spun Yarn: 100% Polyester

Lycra: CREORA, Made in VIETNAM.Invista, Made in SingaporeTexlon, Made in KOREAFlamingoWinWin

2.2 Source of yarn for knittingName of the spinning Mills LocationArif Knit spinning Ltd GazipurThe Delta spinning Mills Ltd Kashimpur, GazipurSquare yarn Ltd Kashimpur, GazipurBengol NFK Textile GazipurNRG spinning mill GazipurPrime Textile Pagla,NarayangongRSWM Ltd IndiaAA Kader synthetics NarangongShirin spinning Ltd Shreepur, GazipurHyosung Vietnam South KoreaMalek spinning Valuka, MymensinghSunny InternationalAman Cotton Fabrics LtdOtto Spinning LtdVDM Spinning LtdBadsha Spinning Mills LtdKamal Spinning Mills LtdAshoka Spinning LtdRusta Spinning LtdBextex MTJLoyed Tex

2.3 DIFFERENT YARN and count FOR Knitting:

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2.4 SUB CONTACT Si No Buyer Name Remark01 Viyella Tex Knitting, Dyeing & Finishing02 Northern ”03 BDL ”04 ADURY ”05 RATUL ”06 M.M Knitwear Ltd. ”07 Epyllion group ”

Expenditure For Raw Materials:Price

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Si/No Yarn Type Composition Yarn Count Remark

01 Carded Yarn 100% Cotton 10s, 12s, 16s, 20s, 20/2, 22s, 24s, 26s,28s, 30, 32s, 34s,

02 Combed Yarn 100% Cotton 20s, 22s, 24s, 26s, 28s, 30s, 32s, 34s, 36s, 40s, 50s, 60s.

03 G/M (Viscose %) 1%, 2%, 5%, 10%, 15%, 20%, 30%, 40%

04 Spun Yarn 100% Polyester

36D, 70D, 72D, 75D,

05 PC Polyster + Cotton

24s, 26s, 28s,30s, 32s, 34s,

06 CVC Cotton + Polyester

24s, 26s, 28s, 30s, 34s, 36s, 40s

07 C/M Cotton 50% + Polyester 50%

26s, 28s, 30s,

08 Lycra Synthetic 20D, 40D, 70D,

SL NO. Yarn Type Yarn Count U.S. Dollar per Kg.

01. Combed 30 2.85

02. Carded 30 2.40

03. Combed 28 2.85

04. Carded 28 2.40

05. Combed 26 2.80

06. Carded 26 2.35

07. Combed 24 2.75

08. Carded 24 2.30

09. Combed 20 2.70

10. Carded 20 2.25

Project report

17.1 CONSUMER OF PRODUCTS

PPC is a 100% export oriented industry. All the goods produced in this industry are exported into various foreign countries. Name of the main buyers are given below:

NAME OF THE BUYER

1. S. Oliver 2. Tom tailor3. IC Company4. Ed Ward Wang5. Umbro6. New Look7. TMS8. Algodon9. Q. Solution11. Maskos12. Walmant13. Up-2-Date14. Grenvilly.15. Asmara16. Erima

17. Sprider18. Esprit19. P.P. Tex20. Gastrock21. Texco22. Maxim23. OBS24. Multiline25. MB Fashion26. DR & S27. Katag28. Collince29. Cream Soda.30. Octagon31. Kiabi

32. Triglobe33. Brice34. Shobi Fashion35. Max.36. Etam37. Zagora38. Air Sohution39. Vood Bridge.40. Lion Star41. Evrozon42. Sumi Tomo43. Ginkana

17.2 COMMUNICATION SYSTEM

Intercom telephone

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Fax E-mail Written letters Oral

17.3 Importing countries

There are some countries which are importing gods from The PPC. The name of the countries are given below –

Spain Germany Denmark Europe Denmark Europe Union

United State of America

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1 . To get idea about the knitted fabric faults named spirility and shrinkage in knitting industry. 2 . To get knowledge about the cause of spirility and shrinkage. 3 . To get knowledge about the processes to minimize spirility and shrinkage problems. 4 . To get idea about the problems associated with spirility and shrinkage.

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1. SpiralitySpirality is a dimensional distortion in circular plain knitted fabrics. The wales or needle lines,

should occupy a truly vertical line in the fabric and should always be right angles to the cross wise courses of stitches. This perpendicularity of wales to the courses is frequently, not the case and many times the wales may skew to the right or left forming an angle, which appears in the form of a twilled surface.

This geometrical defect has been termed spirality of circular knitted fabrics. The following Figure shows the fabrics with normal loop position and with spirality having wale skewness.

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ѲWales Wales

Courses Courses

Fig: Fabric with normal loop position

Fig: Fabric with spirality

Ѳ = dddddddddaAgn

Angle of spirality

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Spirality has definite influence on both the functional and aesthetic performance of knitted fabrics and their garments. Displacements or shifting of seams during the garment make-up, mismatched patterns due to wale skewness, sewing difficulties etc are some important practical difficulties due to spirality. As the dimensional properties of the fabrics are affected by spirality, it is very difficult to minimize or eliminate it altogether. This spirality problem is often corrected in finishing treatments by imposing distortion to fabrics so that the wales straighten out and subsequently set in new from. Though the setting by finishing treatments are normally achieved by using resins, heat, steam, mercerization etc, it is not permanent and after repeated washings, the wale skewness takes place.

1.1. Calculation for spirality percentage :

Average deflection length from the seam line = XY= Sample length,

Spirality% =

Example: Average deflection, X = 2cmSample length, Y = 50cm

Spirality% =

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1. ShrinkageA dimensional change resulting in a decrease in the length or width of a specimen subjected to

specified conditions is known shrinkage. Reduction in length and width of fabric induced by conditioning, wetting, steaming, chemical

treatment, wet processing as in laundering, in chemical practice and in literature the following terms have been used to describe the shrinkage which occurs in testing procedure:

a) Relaxation shrinkage, b) Felting shrinkage, c) Compressive shrinkage, d) Residual shrinkage.

a) Relaxation shrinkage: During manufactures fabrics and their component yarns are subjeceted to tension under varying conditions of temperature and moisture content, after manufacturing when the fabric is taken from the machine and keep on floor or store room, then the fabric tends to shrink, this type shrinkage is called relaxation shrinkage.

b) Felting shrinkage: In case of wool fibers dimensional changes can be magnified by felting shrinkage. When untreated wool fibers are subjected to mechanical action in the presence of moisture.

c) Compressive shrinkage: A process in which fabric is caused to shrink in length by compression. The process often referred to as controlled compressive shrinkage.

d) Residual shrinkage: after washing the fabric is shrunk. This type of shrinkage is called residual shrinkage. Residual shrinkage is the main factor of garments industry.

1. Causes: Shrinkage is mainly due to yarn swelling and the resulting crimp increase during washing in case of

cotton fabrics. Yarn swelling percentage is more in polyester cotton blending yarn.2. Influencing factors:

i) Twist factor: twist factor increases so that shrinkage will be increases.ii) Stitch length: stitch length increases so that shrinkage will be increases.iii) GSM: GSM increases so that shrinkage will be decreases.iv) Elasticity of yarn.

4. Calculation for shrinkage percentage: Shrinkage percentage = (L0-L1) ×100/L0

Where, L0 = the distance between the datum line before washing and L1 = the distance between datum lines after washing.

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SpiralityThe spirality occurred in knitted fabrics is shown in Figure. The fabric is assumed to the knitted with Z twist yarn on a multifeed circular machine, revolving clockwise. Let F = total number of feeders, n= total number of needles, c= courses per unit length, w= wales per unit length

let, DD/ = position of a wale when total spirality occurs. BB/ = position of a wale when total spirality occurs due to number of feeders. XX/= position of a course when total spirality occurs. XA=position of a course when spirality occurs due to number of feeders. X/A= F/C= displace between two consecutive courses knitted by the same feed. XX./ = n/w= open width of the fabric.

Let,

tanѲF =

Now, w and c therefore, loop factor =

tanѲF =

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ѲY = angle of spirality due to yarn

ѲF = angle of spirality due to number of feeder. ѲYF = total spirality

d

X

D/

X/

D

Y

Y

B/

B

ѲY

ѲF

ѲF

Normal to wale line

Wale

A

L

ѲYF

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Therefore, ѲF =tan-1(

now, the above relationship shows that the angle of spirality depends on: i) Number of feeders of the machine, ii) Shape of loop in a particular state of relaxation and iii) Number of active needles in the machine which depends on machine gauge and

diameter.

Procedure of determining the angle of spirality:

• For specimens tested in the original state conditioning is not essential, for processed specimens a minimum of 4 hours in the standard atmosphere is required.

• Determine accurately the path of the course line; this can be achieved by either placing the base of the protractor or a rule along the course line or drawing a line parallel to the course with a fine tip pen.

• Determine accurately the path of the wale line that intersects with the drawn course line, draw along this wale line.

• Place the protractor along a course line ensuring wale intersects with the bottom of the 90 line on the protractor (Figure 4).

• The angle between the 90 lines and wale line is measured and the direction of spirality (+ right, - left) is recorded.

• Repeat the process nine more times so that ten results are recorded and the mean is determined.

Figure 4: Schematic representation of the measurement of spirality angle

As per the experts and different world renowned buyers, the angle of spirality lesser than 10 degree is acceptable as performance requirement and it is expected that within that threshold limit knit loops will not pose any serious problem.

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Washing process: ISO 6330 Detergent: suitable detergent (0.5%) on the weight of 1.8kg sample. Sample size: 62cm×62cmMarking area: 50cm×50cm Time: 45minTemperature: 400CMachine RPM: 1100

Determination of spirality after laundering knitted fabrics:ISO 16322-2

First Edition 2005-06-01(1) Principle: Test specimen are cut, prepared, marked and laundered according to specified

procedure. Spirality is measured in millimeters, percentage of a marked distance or angle of nonverticality.

(2) Apparatus: (a) Automatic washing machine as described in ISO 6330 (b) Automatic drying machine(c) Calibrated roll(d) Conditioning rack (e) Sewing machine(f) Inverted T-square at least 500mm in length(g) Marking template of dimensions(380*380)mm,(530*510)mm or (680*380)mm

(3) Conditioning: For a minimum four hours before cuttings, sewing or measuring the fabric specimens.

Test specimen preparation & marking procedures:

Test specimen preparation: Prepare these specimens for marking from approlllede locations across a fabric sample. Cut three 380*380 mm single layer fabric specimen aligned with the selvedge or tubular fold line in selected locations with different length and width yarns. Diagonal marking procedure: Mark two pairs of 250mm benchmark sets parallel to the length and two pairs of 250mm benchmark sets perpendicular to the width to make a square. Draw a line through each of the four sets of adjacent benchmark to denote the square formed. Label the corners A, B, C & D in a clockwise direction starting at the lower left corner.

1) Test specimen preparation: This marking procedure is particularly suited to narrow width fabrics. Cut three 680*380 mm specimens with the long dimensions aligned with the selvedge or folded edge if the samples are a tubular knit.

2) Inverted T-marking: Draw a line, YZ, across the width of the specimen 75mm above the edge of the specimen.

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Procedure-A-Diagonal Marking

Procedure-B: Inverted marking

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Place benchmark A perpendicular to the YZ line midway along the horizontal line using T-square device, mark point B 500mm above point A on the vertical line

1) Test specimen preparation: Fold the fabric with the selvedge edges together. Place a 580*510 mm template on the fabric with the long direction parallel to the selvedge. Cut a double thickness.

2) Mock garments marking: Place face side together so that the two 580mm long edges are even, as well as the shorted 510mm sew a 12mm over edged seamed along each long direction and one short direction. Turn seams to the inside forming an open-ended bag or pillow type specimen to simulate a garments panel. Stitch unsewn edges of specimen to make a hemmed edge. Measure and record distance along the seamed edges, lines OB & CD of each specimen

Assessment by procedure: Procedure-A: Diagonal marking Normal assessment: After laundering measure and record distances AC & BD in mm.Calculate the spirality% (X) for each specimen to the nearest 0.1% as follow:

AC = diagonal distance across the specimen for A to C BD = diagonal distance across the specimen for B to D.

Procedure-B: Inverted T-marking After laundering place the horizontal leg of a right angle device along line YZ and the second leg on a perpendicular downward from point B. place a benchmark on line YZ that corresponds to point A / inMeasure and record the length of lines AA/ and AB to the nearest millimeter. Calculate the percentage spirality (X) to 0.1% for each specimen as follows,

Calculate and report the mean percentage spirality for the specimens tested. The mean distance of AA / to the nearest millimeter may also report as the spirality distance, if desired. Procedure-C: Mock garments markingAfter laundering, measure and record the distance of lines AA/, DD/, AB & CD of the specimen to the nearest millimeter.Calculate the mean percentage spirality (X) to the nearest o,1% for each specimen as follows,

Calculate and report the mean percentage spirality for the specimens tested. The mean distance of AA/ or DD/ to the nearest millimeter may also be reported as the spirality distance, if desired.

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Procedure-C: Mock garments marking

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Spirality control: In conventional open width knitting machine the fabric is cut vertically without considering its

distortion problem. If the fabric is cut helically or parallel to the angle of the inclination of the knitted wales, the results the cut fabric is stable and will not distort further.

Spirality is controlled at different stages after dyeing; such as dewatering machine, compacting machine or stenter machine. During passing the fabric through albatross (the width controller of squeezer machine) and shape pulley ( the width controller of compacting machine) .

(13) Effect of stenter m/c: If the fabric is delivered to the dryer without sending through the stenter m/c and completed garments that show lower spirality, higher shrinkage. On the contrary, it shows tolerate limit according to buyer requirements by going through the stenter m/c.

Before stenter (For Plain Single Jersey Farbic):

After stenter (For Plain Single Jersey Farbic):

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Serial Fabric GSM Spirality (%)01 180 0.502 180 0.403 180 004 180 005 180 0

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SHRINKAGE

Washing process: ISO 6330 Detergent: suitable detergent (0.5%) on the weight of 1.8kg sample. Sample size: 62cm×62cmMarking area: 50cm×50cm Time: 45minTemperature: 400CMachine RPM: 1100

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Serial Fabric GSM Spirality (%)

01 175 3.3

02 175 3

03 175 3.7

04 175 3.5

05 175 3.8

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Determination of dimensional change in washing and drying:International Standard ISO 5077First edition- 1984-12-01(1) Principle : The specimen is conditioned in the specified standard atmosphere and measured before subjection to the appropriate washing and drying procedure. After drying and conditioning and measuring of the specimen, the changes in dimensions are calculated.(2) Apparatus and reagents: Specified in ISO 3759 and in ISO 6330.

(3) Atmospheric Condition: The atmospheric conditions required for pre-conditioning and testing are specified in ISO 139.

(4) Test specimens: (a) The selection, dimensions, marking and measuring of test specimens are specified in ISO 3759.(b) The number of specimens to be tested is determined by the precision of the results required. In this test method, it is suggested that four specimens of each sample be tested and these specimens be washed in two separate wash loads with two specimens per wash load.(c) In certain circumstances, it may be desirable not to test four specimen may be used.

(5) Procedure: (a) Determine the original length and width dimensions, as appropriate after the specimens have been pre –conditioned, conditioned and measured according to the procedure specified in ISO 3759(b) Wash and dry the specimens according to one of the procedures specified in ISO 6330, as agreed between the interested parties.(c) After washing and drying, condition and measure the specimens and calculate the dimensional change of the specimens according to the procedure specified in ISO 3759.

(6) Expression of results: (a) Calculate the mean changes in dimensions in both the length and width directions accordance with the arrangement in ISO 3759 as follows:

Percentage change in length= ×100

Percentage change in width=

(b) Express the average dimensional changes to the nearest 0.5%.(c) State whether the dimension has decreased (shrinkage) by means of a minus sign (-) or increased (extension) by means of a plus sign (+).

Practical data:

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FOR 100% COTTON PLAIN SINGLE JERSEY

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Effect of GSM on Shrinkage (Tumble Dry):

Effect of GSM on Shrinkage:

Sample No. Tumble Dry Hang Dry Flat Dry Length wise Width wise Length wise Width wise Length wise Width wise

01 +1 +2 +0.75 +1 +1 +202 0 +1 0 +1 0 +103 -1 -2 -1 -2 -1 -204 +0.75 +1 +0.75 +1 +0.75 +105 +2 +1 +1 +2 +2 +1

Effect of Fabric Structure on Shrinkage(Tumble Dry):

Sample No. PK ( 220 GSM) 1*1 RIB (220 GSM) INTERLOCK ( 220 GSM) Length wise Width wise Length wise Width wise Length wise Width wise

01 -4.37 -4 -3.64 +1.04 -3.93 002 -4.34 -4.9 -4.85 -3.49 -2.17 -1.903 -2.17 -4.95 0 -3 -1.15 -2.9104 -4.34 -3.84 -2.89 -5.05 -1.48 -2.0405 -4.83 -1.94 0 -4 -4.34 -2.02

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Sample No.

Shrinkage

120 GSM 130 GSM 140 GSM 160 GSM 180 GSM

Length wise

Width wise

Length wise

Width wise

Length wise

Width wise

Length wise

Width wise

Length wise

Width wise

01 -6.5% -5% -4.4% -5% -3.62 -1.96 -3.32 -2.18 -2.18 -2.0802 -4.51% -4.16% -3.74 -2.09 -3.7 -0.96 -3.17 -2.5 -2.72 -2.13

03 -5.74 -2.41 -4.15 -4.9 -3.43 -6.06 -3.37 -2.33 -2.74 -2.1704 -4.44 -3.92 -4.22 -3.37 -3.18 -4.12 -2.94 -2.29 -1.17 -2.1905 -4.7 -6.12 -3.75 -0.99 -3.56 -4 -3.15 -2.2 -0.72 -2.03

FOR 100% POLYESTER PLAIN SINGLE JERSEY FARBIC

FOR 100% COTTON YARN

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The residual torque or twist liveliness.

Count of yarn,

Fabric structure,

GSM

Fabric Relaxation,

No. of feeder.

Twist direction,

Machine rotation

Spinning system,

Fabric finishing.

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PROBLEM ASSOCIATED WITH SHRINKAGE:Shrinkage is rated as one of the leading quality problems in the garments industry.Fabric shrinkage can cause problem into main areas , either during garmen manufacture or during subsequent laundering by the ultimate customer.Fabric relaxtion shrinkage may cause sizing problem ,as athe finished garments will be smaller than it was planned .It also leads in formation of puckeredseams infinal pressing.

PROBLEM ASSOCIATED WITH SPIRALITY:Spirality has definite influence on both the functional and aesthetic performance of knitted fabrics and their garments. Displacements or shifting of seams during the garments make-up mismatched patterns due to wale skewness sewing difficulties etc are some important practical difficulties due to spirality

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Remedies For Spirality:

1) Z & S twist yarn package used in alternate feeder:

If Z and S twist yarn packages are used in alternate feeder then legs than 1% spirality is found and this is the greatest way to reduce spirality;.

2) Resin treatment:

Cross linking the fabric by means of inter fibre bonding also reduces spirality. Resin is the form of aqueous solution is applied and set by passing the fabric through a high temperature stenter this method is not recommend fro cotton fabrics, since it weakens the cotton yarn.

3) Heat setting:

Steam or hot water setting reduces twist liveliness and hence spirality. Mercerization is recommended for cotton yarn, sot that fibers are made to relax permanently.

4) Compacting:

If the length of the fabric based on its elongation during processing which, in turn, reduces the width. It helps in controlling the shrinkage of the fabric. There are two types of compactors, open and tubular. In tubular compacting the squeezing line gets on the sides in this process and is done on natural movement thus controlling spirality. If the wales are straightened manually then it results in spirality.

5) Yarn twist direction and machine rotation direction:

If the machine rotates clockwise then the spirality can be reduced by suing yarn of S-twist. Otherwise if the machine rotates anti-clockwise the spirality can be reduced by using the yarn of Z-twist.

6) Use of special type of yarn:

One comparative way minimize the spirality is to use the vortex spun yarn which is obtained from Murata vortex spinning system. And modified friction spun DREF III yarn reduces yarn snarling and fabric spirality.

7) By using plating yarn:

In fabric production when used plating yarn it reduce the spirality.

8) By using special type spinning system:

9) By using “Nu-Torque” spinning system the produced yarn torque is zero. And by using this yarn in fabric it reduces the spirality.

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project report

Remedies for Shrinkage: 1) In order to maintain the weight at a lower shrinkage, a finer yarn is used. 2) In order to maintain the width, a larger dia knitting machine or a longer stitch length is necessary. 3) In order to maintain the same knitted tightness factor, or cover factor (square root of tex divided

by stitch length) with a finer yarn, a shorter average stitch length must be knitted. 4) Changes in yarn count and stitch length also change the stitch density which again changes the

weight and the width for a given level of shrinkage. Changes in the tightness factor will change the extensibility of the fabric and will also affect the amount of spirality (fabric twisting) which may be developed.

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project report

In general the angle of spirality values are decreasing, when the tightness factor values are getting tight in the all knitted fabric samples. In slack knitted fabric structures, the loop can easily find area to rotate so 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 the effect of the spiraled on twist liveliness. Because the twist liveliness of the ring yarns used in producing single jersey fabric is higher than the open-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% cotton and polyester and synthetic yarn. More research and development is required to control the fabric specifications accurately. We could not able to execute the project work perfectly for limitations of time and lack of opportunity to examine the various tests in the factory.

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