1. Project report
PROJECT WORK
ON
.
Supervised by
A.K.M FARIDUL AZAD
HEAD 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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2. Project report
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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3. Project report
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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5. Project report
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 to
famous Dhaka muslin. Fabrics from Bengal were found in ancient Egyptian tombs, and were
traded with the Roman and Chinese empires in the medieval age. In ancient Bengal a great
deal of expertise existed with regards to weaving of textile products as well as great
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6. Project report
reverence towards its trade. In rural communities both men and women were apprenticed in
weaving. These skills and disciplines in sewing and weaving are passed down through
generations and are quickly transferred to production lines in modern knitwear factories.
In the early 1980s, there were small-scale independent investments in the readymade
garments (RMG) sector. At that time, it was not considered viable and received very little
government attention. Within a decade, the RMG industry in Bangladesh had flourished and
by the early 1990s it had emerged as a major employer. Under the dynamic leadership of the
private sector together with policy support from the government, the export oriented RMG
industry has shown a spectacular growth during the last two and a half decades. The textile
sector initially could not keep pace with the requirement of yarn and fabrics particularly by
the woven RMG sector as the textile and clothing industry was controlled by a fairly small
community of local entrepreneurs. However, the sector grew with vengeance and the country
currently exports over US$11 billion in textiles and garments, with a projected target of
US$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 knitwear
sector’s significant contribution in country’s export share was 1.1% in FY 82. Since then it
gradually increased its share in exports. While the contribution of woven garments to the
4
export basket was 42.8% in FY 91, the knitwear sector’s contribution rose to 7.6%. Table 1
presents export performance and the extent of retention rate due to high contents of domestic
inputs. In FY 04, knitwear sector for the first time exceeded woven sector and became the
leader with an exported quantity of 91.6 million dozens. The sector continues to be the leader
in 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 equal
to 163.7% growth between FY 04 and FY 08. At present knitwear is the largest export
earning sector of Bangladesh contributing 41.8% to national export earnings at the end of FY
09 (July-April).
Total Knitwear Exports and Net Retention in Bangladesh:
Exports (US $
million)
Share of Net
Retention
Share of
Year Total
RMG
Knitwear Knitwear
(%)
(US $
million)
Net
Retention
(%)
1994-95 1850.3 393.3 21.3 157.3 40
1995-96 2006.6 598.3 29.8 253.7 42.4
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7. Project report
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 59.2
2004-05 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. With
their earnest efforts from late 1980s the RMG exporters were able to export US$ 393.26
million in FY 95. Of this amount, the shares of the EU and the USA were US$ 274 million
and US$ 98 million respectively. During FY 97, Bangladesh was the 7th and the 5th largest
apparel exporter to the US and EU markets respectively. The cumulative average growth rate
of the sector is about 20%. In recent years the EU market was the main export market for
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Bangladeshi knitwear constituting 76% (US$ 4.2 billion) of total knitwear export followed by
the USA (14.59%, i.e. US$ 807 million) in the year FY 08. The impressive growth of the
knitwear in the EU market was partly due the market access opportunities provided under the
Generalized Systems of Preference (GSP) facility. Further, the two-stage transformation
requirement 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 motivated
workers. The sector has created jobs for about 2.5 million people (Table 4) of which 70% are
women originating mostly from rural areas. Due to a liberal cultural attitude towards women
in the workforce, the RMG sector has transformed a traditionally male dominated society to
one 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 a
thousand in FY 91 to about five thousands in FY 08. Competitive wage rate together with
easily trainable workforce helps transform the comparative advantages into copetitive
advantage in this sector. Directly employed labor force in the knitwear sector are 1 million
and another 0.5 millions are indirectly employed.
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8. Project report
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 Yarn
Combed Yarn
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9. Project report
Cotton + Modal
Cotton + Viscose
Spun Yarn: 100% Polyester
Lycra: CREORA, Made in VIETNAM.
Invista, Made in Singapore
Texlon, Made in KOREA
Flamingo
WinWin
2.2 Source of yarn for knitting
Name of the spinning Mills Location
Arif Knit spinning Ltd Gazipur
The Delta spinning Mills Ltd Kashimpur, Gazipur
Square yarn Ltd Kashimpur, Gazipur
Bengol NFK Textile Gazipur
NRG spinning mill Gazipur
Prime Textile Pagla,Narayangong
RSWM Ltd India
AA Kader synthetics Narangong
Shirin spinning Ltd Shreepur, Gazipur
Hyosung Vietnam South Korea
Malek spinning Valuka, Mymensingh
Sunny International
Aman Cotton Fabrics Ltd
Otto Spinning Ltd
VDM Spinning Ltd
Badsha Spinning Mills Ltd
Kamal Spinning Mills Ltd
Ashoka Spinning Ltd
Rusta Spinning Ltd
Bextex
MTJ
Loyed Tex
2.3 DIFFERENT YARN and count FOR Knitting:
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11. 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 tailor
3. IC Company
4. Ed Ward Wang
5. Umbro
6. New Look
7. TMS
8. Algodon
9. Q. Solution
11. Maskos
12. Walmant
13. Up-2-Date
14. Grenvilly.
15. Asmara
16. Erima
17. Sprider
18. Esprit
19. P.P. Tex
20. Gastrock
21. Texco
22. Maxim
23. OBS
24. Multiline
25. MB Fashion
26. DR & S
27. Katag
28. Collince
29. Cream Soda.
30. Octagon
31. Kiabi
32. Triglobe
33. Brice
34. Shobi Fashion
35. Max.
36. Etam
37. Zagora
38. Air Sohution
39. Vood Bridge.
40. Lion Star
41. Evrozon
42. Sumi Tomo
43. Ginkana
17.2 COMMUNICATION SYSTEM
Intercom telephone
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12. Project report
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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13. project report
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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14. project report
1. Spirality
Spirality 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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Ѳ
Wales
Wales
Courses
Courses
Fig: Fabric with normal loop
position
Fig: Fabric with spirality
Ѳ =
dddddddddaAgn
Angle of spirality
15. project report
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 = X
Y= Sample length,
Spirality% =
Example:
Average deflection, X = 2cm
Sample length, Y = 50cm
Spirality% =
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16. project report
1. Shrinkage
A 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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17. project report
Spirality
The 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
18. project report
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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19. project report
Washing process:
ISO 6330
Detergent: suitable detergent (0.5%) on the weight of 1.8kg sample.
Sample size: 62cm×62cm
Marking area: 50cm×50cm
Time: 45min
Temperature: 400
C
Machine 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
20. project report
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/
in
Measure 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 marking
After 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
21. project report
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 0.5
02 180 0.4
03 180 0
04 180 0
05 180 0
22. project report
SHRINKAGE
Washing process:
ISO 6330
Detergent: suitable detergent (0.5%) on the weight of 1.8kg sample.
Sample size: 62cm×62cm
Marking area: 50cm×50cm
Time: 45min
Temperature: 400
C
Machine RPM: 1100
Page | 22
Serial Fabric GSM Spirality (%)
01 175 3.3
02 175 3
03 175 3.7
04 175 3.5
05 175 3.8
23. project report
Determination of dimensional change in washing and drying:
International Standard ISO 5077
First 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
26. project report
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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27. project report
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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28. 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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29. 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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