effect of elastane

7/31/2019 Effect of Elastane

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Chapter 1

General Introduction


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other thread is fed to the needles in such a way that it forms the back or reverse

of the final fabric. In the case of single-bed circular knitting machines elastane

must always be fed in via a plating yarn guide. This guide presents generally a

feeding roll permitting Lycra guiding with minimum friction [vi, vii]. Positive feed

Fig 2.Elastane plated single jersey plain knitted fabric pattern

mechanisms where the unwinding elastane bobbin is driven have become the

most common feed systems in large-diameter circular knitting when processing

elastane yarn. The bobbin is driven positively in these delivery systems. After

unwinding, the yarn passes through an electric stopping device and is then fed to

the needle through the plating roll. Elastane yarn proportion is one of the most

important parameter of single jersey plated fabric. The proportion of elastane

inside fabric influences fabric characteristics [vii]. The adjustment of elastane

proportion is obtained through the setting elastane delivery system speed. There

is no rigorous physical law that enables to determine with precision the necessary

elastane consumption for given fabric properties. The relation between elastane

proportion and fabric width, weight or elasticity is generally not well known. Most

of knitters have to carry out some tests and adjust gradually knitting parameters

in order to reach the needed elastane proportion and the right fabric properties.

The obtained adjustments serves generally as a base for furthers settings. The

aims of this project work is to study the effect of elastane on the basic principle

physical properties; they are GSM, Air Permeability, Pilling, Spirality, Loop length,

Course Spacing, Wale Spacing, course/cm, wales/Spacing, Stitch density, Bursting

Strength & Shrinkage test. This would help commercial knitter to understand the

effect of elastane on fabric properties.


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Chapter 2

Literature Review


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2.1- INTRODUCTION :

Elastane is a synthetic polymer. Chemically, it is made up of a long-chainpolyglycol combined with a short di-isocyanate, and contains at least

85%polyurethane. It is an elastomer, which means it can be stretched to a certaindegree and it recoils when released. These fibers are superior to rubber becausethey are stronger, lighter, and more versatile. In fact, elastane fibers can bestretched to almost 500% of their length.

This unique elastic property of the elastane fibers is a direct result of the material'schemical composition. The fibers are made up of numerous polymer strands. Thesestrands are composed of two types of segments: long, amorphous segments andshort, rigid segments. In their natural state, the amorphous segments have a randommolecular structure. They intermingle and make the fibers soft. Some of the rigid

portions of the polymers bond with each other and give the fiber structure. When aforce is applied to stretch the fibers, the bonds between the rigid sections arebroken, and the amorphous segments straighten out. This makes the amorphoussegments longer, thereby increasing the length of the fiber. When the fiber isstretched to its maximum length, the rigid segments again bond with each other.The amorphous segments remain in an elongated state. This makes the fiber stifferand stronger. After the force is removed, the amorphous segments recoil and thefiber returns to its relaxed state. By using the elastic properties of elastane fibers,scientists can create fabrics that have desirable stretching and strengthcharacteristics.

The primary use for elastane fibers is in fabric. They are useful for a number ofreasons. First, they can be stretched repeatedly, and will return almost exactly backto original size and shape. Second, they are lightweight, soft, and smooth.Additionally, they are easily dyed. They are also resilient since them are resistantto abrasion and the deleterious effects of body oils, perspiration, and detergents.They are compatible with other materials, and can be spun with other types offibers to produce unique fabrics, which have characteristics of both fibers.

Elastane is used in a variety of different clothing types. Since it is lightweight anddoes not restrict movement, it is most often used in athletic wear. This includessuch garments as swimsuits, bicycle pants, and exercise wear. The form-fittingproperties of elastane make it a good for use in under-garments. Hence, it is used inwaist bands, support hose, bras, and briefs.
http://www.answers.com/topic/polyglycolhttp://www.answers.com/topic/elastomerhttp://www.answers.com/topic/elastichttp://www.answers.com/topic/amorphoushttp://www.answers.com/topic/straightenhttp://www.answers.com/topic/recoilhttp://www.answers.com/topic/resilienthttp://www.answers.com/topic/abrasionhttp://www.answers.com/topic/deleterioushttp://www.answers.com/topic/perspirationhttp://www.answers.com/topic/waisthttp://www.answers.com/topic/hosehttp://www.answers.com/topic/hosehttp://www.answers.com/topic/waisthttp://www.answers.com/topic/perspirationhttp://www.answers.com/topic/deleterioushttp://www.answers.com/topic/abrasionhttp://www.answers.com/topic/resilienthttp://www.answers.com/topic/recoilhttp://www.answers.com/topic/straightenhttp://www.answers.com/topic/amorphoushttp://www.answers.com/topic/elastichttp://www.answers.com/topic/elastomerhttp://www.answers.com/topic/polyglycol


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2.2HISTORY OF ELASTANE FIBRE :

The development of elastane was started during World War II. At this time,chemists took on the challenge of developing synthetic replacements for rubber.Two primary motivating factors prompted their research. First, the war effortrequired most of the available rubber for building equipment. Second, the price ofrubber was unstable and it fluctuated frequently. Developing an alternative torubber could solve both of these problems.

At first, their goal was to develop a durable elastic strand based on syntheticpolymers. In 1940, the first polyurethane elastomers were produced. Thesepolymers produced millable gums, which were an adequate alternative to rubber.Around the same time, scientists at Du Pont produced the first nylon polymers.

These early nylon polymers were stiff and rigid, so efforts were begun to makethem more elastic. When scientists found that other polyurethanes could be madeinto fine threads, they decided that these materials might be useful in making morestretchable nylons or in making lightweight garments.

The first elastane fibers were produced on an experimental level by one of theearly pioneers in polymer chemistry, Farbenfabriken Bayer. He earned a Germanpatent for his synthesis in 1952. The final development of the fibers was workedout independently by scientists at Du Pont and the U.S. Rubber Company. Du Pontused the brand name Lycra and began full scale manufacture in 1962. They are

currently the world leader in the production of elastane fibers.

Elastane or elastane is a synthetic fiber known for its exceptional elasticity. It isstrong, but less durable than its major non-synthetic competitor, natural Latex. It isa polyurethane-polyureacopolymer that was developed in 1959 by chemists C. L.Sandquist and Joseph Shivers at DuPont's Benger Laboratory in Waynesboro,Virginia. When first introduced, it revolutionized many areas of theclothingindustry.
http://www.answers.com/topic/fluctuatehttp://www.answers.com/topic/durablehttp://www.answers.com/topic/synthetic-polymerhttp://www.answers.com/topic/synthetic-polymerhttp://www.answers.com/topic/synthetic-fibershttp://www.answers.com/topic/elasticity-physicshttp://www.answers.com/topic/latex-11http://www.answers.com/topic/polyurethanehttp://www.answers.com/topic/polyureahttp://www.answers.com/topic/joseph-shivershttp://www.answers.com/topic/dupont-2http://www.answers.com/topic/waynesboro-virginiahttp://www.answers.com/topic/waynesboro-virginiahttp://www.answers.com/topic/clothinghttp://www.answers.com/topic/clothinghttp://www.answers.com/topic/waynesboro-virginiahttp://www.answers.com/topic/waynesboro-virginiahttp://www.answers.com/topic/dupont-2http://www.answers.com/topic/joseph-shivershttp://www.answers.com/topic/polyureahttp://www.answers.com/topic/polyureahttp://www.answers.com/topic/polyurethanehttp://www.answers.com/topic/latex-11http://www.answers.com/topic/elasticity-physicshttp://www.answers.com/topic/synthetic-fibershttp://www.answers.com/topic/synthetic-polymerhttp://www.answers.com/topic/synthetic-polymerhttp://www.answers.com/topic/durablehttp://www.answers.com/topic/fluctuate


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2.3MANUFACTURING PROCESS OF ELASTANE :

RAW MATERIALS:

A variety of raw materials are used to produce stretchable elastane fibers. Thisincludes prepolymers which produce the backbone of the fiber, stabilizers whichprotect the integrity of the polymer, and colorants.

Two types of prepolymers are reacted to produce the elastane fiber polymer back-bone. One is a flexible macroglycol while the other is a stiff di-isocyanate. Themacro-glycol can be polyester, polyether, polycarbonate, polycaprolactone or somecombination of these. These are long chain polymers, which have hydroxyl groups(-OH) on both ends. The important feature of these molecules is that they are longand flexible. This part of the elastane fiber is responsible for its stretching

characteristic. The other prepolymer used to produce elastane is a polymericdiisocyanate. This is a shorter chain polymer, which has an isocyanate (-NCO)group on both ends. The principal characteristic of this molecule is its rigidity. Inthe fiber, this molecule provides strength.

Elastane fibers are produced in four different ways including melt extrusion,reaction spinning, solution dry spinning, and solution wet spinning. Each of thesemethods involve the initial step of reacting monomers to produce a prepolymer.Then the prepolymer is reacted further, in various ways, and drawn out to producea long fiber. Since solution dry spinning is used to produce over 90% of the world'selastane fibers, it is described.

Dry-Spinning Process:

Step 1: The first step is to produce the prepolymer. This is done by mixing amacroglycol with a diisocyanate monomer. The two compounds are mixed in areaction vessel to produce a prepolymer. A typical ratio of glycol to diisocyanate is1:2

Step 2: The prepolymer is further reacted with an equal amount of diamine. Thisreaction is known as chain extension reaction. The resulting solution is dilutedwith a solvent to produce the spinning solution. The solvent helps make thesolution thinner and more easily handled, and then it can be pumped into the fibreproduction cell.
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Tasmaci[3] researched the dimensional properties of single jersey fabrics

knitted from cotton, viscose, and PES yarns with or without elastane, He found

that for elastane-containing fabrics,variations were higher both width-wise

and for weight, Furthermore, the appearance of fiber surfaces was smoother.

Meri B., Grarda A [4] studied the mechanical properties of fabrics

containing elastane and concluded that high elastane content makes the yarn

flexible; however, the yarn that will be used with elastane should allow the

fabric to move freely and shouldnt cause any deformation in the fabric.

A. B. Marmarali [5] investigated the physical and dimensional properties of

elastic single jersey fabrics, and A. Marmarali, N. zdil and S. D. Kretzschmar

[6] studied the effect of the elastane content in fabrics on their thermal

properties and relative water vapor permeability.

In the literature, some studies aimed to conceive new plating devices or to

design new plated fabrics [7, 8]. Cuden et al. studied experimentally the

evolution of the characteristics of elastane plated plain knitted fabric after

finishing and relaxation but did not investigated the effect of elastane ratio on

these characteristics. [9]. Studies which specifically treat the relation between

elastane proportion and plated fabric performances are extremely rare. Some

researchs available in literature [10, 11] described the relation between therate of elastane and some fabric properties such as extensibility and fatigue

but they concerned only weaved fabrics made with elastane core-spun weft

yarns.


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2.5REFFERENCE :

[1] Schulze, U. (1993), Rechts/Links-Rundstrick-Bindungen nDurKombinationmitDorlastan, Wirkerei und Strickerei Tech., 5, p: 456.

[2] Ceken, F., 1995, Some Investigations of the Dimensional Properties of KnittedFabrics Containing Different Materials, Doctoral thesis, Ege University, Izmir.

[3] Tasmaci, M., 1996, Effects of Spandex Yarn on Single Jersey Fabrics Knittedwith Naked Lycra Yarn, TekstilveKonfeksiyon, 6, p: 422-426.

[4] Meri B., Grarda A., Proceeding of the XIIth Textile and Leather RomanianConference, October 2002, pp. 17-19.

[5] Marmaral, A., 2003, Dimensional and Physical Properties of Cotton /SpandexSingle Jersey Fabrics, Textile Research Journal, 73(1), p: 11-14.

[6] Marmaral, A., zdil, N. and DnmezKretzschmar, S., 2006, ThermalComfort and Elastic Knitted Fabrics, International Conf. CIRAT- 2, Monastir-Tunisia.

[7] Baozhu, K., Weiyuan, Z., "The optimal design of three-layer plated fabrics",Fibres & Textiles in Eastern Europe, 15, 2007, 59-61.

[8] Bruer, S. M., Powell, M., Smith, G., "Three dimensionally knit spacer fabrics: areview of production techniques", Journal of Textile and Apparel, Technology andManagement, 4, 2005, 1-31.

[9] Cuden, A. P., Srdjak, M., Pelko, H., "Optimization of the cotton/Lycra plainknitted Fabric parameters", International Journal of Polymeric Materials, 47, 2000,633648.

[10] zdil, N., "Stretch and Bagging Properties of Denim Fabrics ContainingDifferent Rates of Elastane", Fibres and Textiles in Eastern Europe, 1, 2008, 63-67.

[11] Gorjanc, S., Bukosek V., "The behaviour of fabric with elastane yarn duringstretching, Fibres and Textiles in Eastern Europe, 3, 2008, 63-68.


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Books

Jerde, Judith.Encyclopedia of Textiles. Facts on File, 1992.

Lewin, M. and J. Preston, ed.High Technology Fibers. New York: Marcel Dekker,

1985.

Other

i. Devra, A. U.S. Patent 5,303, 882, 1994.Goodrich, C & W. Evans. U.S. Patent 5,028,642, 1991.

[Article by: Perry Romanowski].

ii. Bayazit, A., Introduction to Weft knitting, EgeUniv..TkaumYayin No.9,Izmir,2000.

iii. Ceken. F., Some Investigations of the dimensional properties of knitted offabrics containing different materials. Doctoral thesis, EgeUniv.. Izmir.

1995.


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Chapter 3

Materials & Methods


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Two separate single jersey samples were knitted: one with cotton

alone and the other one as cotton/elastane fabrics (elastane in every

course).Samples were obtained at medium loop length values, representing

a medium fabric. Both the samples are produced in Mayer & Cie Single

jersey Circular Knitting Machine of 30 dia & 24 gauge. 30/1 ring spun

cotton yarn & 40Denier Elastane were used in the experiment. An IRO

MER2 system was used to feed the elastane, and yarn tension was 6 cN.

The samples were subjected to the dyeing, washing and finishing

processes. All the processes are done according to the current practice.

Measurements were taken on samples as follows:

Loop length [l(mm)]: The length of five unrowed courses, each of which

contained fifty wales, was measured on a Hatra-like tester by putting a 10

g weight on the underside and the average was calculated. This average

value was divided by fifty to find the length of one loop. The process done

both for the 100% cotton and cotton/elastane sample.

Course/cm and wales/cm:The numbers of courses and wales in a 1

length of fabric were determined at ten different places on every samplewith a magnifying glass, and the average values were calculated. Then we

can calculate wales/cm & courses/cm by the following formula:

courses/cm=courses/inch/2.54 &

wales/cm=wales/inch/2.54.

Stitch Density: We can calculate stitch density by multiplying courses/cm

and wales/cm


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Sample: 100% cotton

Sample: 96% cotton & 4% elastane (full feeder)


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Course [c (mm)] and wales spacing [w (mm)]: The values of course

and wales spacing were obtained with the help of two formulas, c (mm) =

25.4/courses per inch and w (mm) = 25.4/wales per inch.

GSM Test

Test Standard ISO 33071

Five samples are taken by using GSM cutter. Then they are weighted on

the electric balance. From those data the average value is calculated.

Pilling tests

After rubbing of a fabric it is possible to assess the amount of pilling

quantitatively either by counting the number of pills or by removing and

weighing them. However, pills observed In worn garments vary in size and

appearance as well as in number. The appearance depends on the

presence of lint in the pills or the degree of colour contrast with the ground

fabric. These factors are not evaluated if the pilling is rated solely on the

number or size of pills. Furthermore the development of pills is often

accompanied by other surface changes such as the development of fuzzwhich affect the overall acceptability of a fabric. It is therefore desirable

that fabrics tested in the laboratory are assessed subjectively with regard

to their acceptability and not rated solely on the number of pills developed.

Counting the pills and/or weighing them as a measure of pilling is very time

consuming and there is also the difficulty of deciding which surface

disturbances constitute pills. The more usual way of evaluation is to assess

the pilling subjectively by comparing it with either standard samples or with

photographs of them or by the use of a written scale of severity. Mostscales are divided into five grades and run from grade 5, no pilling, to

grade 1, very severe pilling.


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Test Method

Here the test method used for pilling is ISO 12945-1:2000. For this test

[4] four specimens each 125mm X 125mm are cut from the fabric. A seam

allowance of 12mm is marked on the back of each square. In two of thesamples the seam is marked parallel to the warp direction and in the other

two parallel to the weft direction. The samples are then folded face to face

and a seam is sewn on the marked line. This gives two specimens with the

seam parallel to the warp and two with the seam parallel to the weft. Each

specimen is turned inside out and 6mm cut off each end of it thus

removing any sewing distortion. The fabric tubes made are then mounted

on rubber tubes so that the length of tube showing at each end is the

same. Each of the loose ends is taped with poly (vinyl chloride) (PVC) tapeso that 6mm of the rubber tube is left exposed as shown in Fig. 7.4. All

four specimens are then placed in one pilling box. The samples are then

Table : Pilling grades

Rating Description Points to be taken intoconsideration

5 No change No visual change

4 Slight change The specimen mayexhibit one or both ofthe

3 Moderate changefollowing:

(a) moderate fuzzing

(b) isolated fully formed

pills2 Significant change Distinct fuzzing

and/or pilling1 Severe change Dense fuzzing and/or

pilling which covers thespecimen.


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Fig 4: preparation of a pilling sample

tumbled together in a cork-lined box as shown in Fig. 7.5. The usual

number of revolutions used in the test is 18,000 which takes 5 h. Some

specifications require the test to be run for a different number of

revolutions.

Assessment

The specimens are removed from the tubes and viewed using oblique

lighting in order to throw the pills into relief. The samples are then given a

rating of between 1 and 5 with the help of the descriptions in Table.

Air permeability

The air permeability of a fabric is a measure of how well it allows the

passage of air through it.

Air permeability is defined as the volume of air in milliliters which is passed

in one second through 10Os mm2 of the fabric at a pressure difference of

10mm head of water. Air permeability, a given area in the vertical direction

of the air flow rate, a given time period, is measured by the fabric test area

inside the pressure difference of the fabric. Basically, it depends on weight,


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thickness and porosity of fabric. The porosity of fabric is the demonstration

of the air gap as a percentage within fabric.

Materials & Equipment

Standard atmospheric conditions, air permeability tester, and test samples

The features of an Air permeability test device

a. Circular sample holder: The circular sample holder must have a central

aperture which can give the opportunity to the experiment in an area.

b. Tools for the holders: That should be taken some precautions for

preventing the air leakage around the edges of the test pieces.

Alternatively, the leak can be measured separately and can be removedfrom the experimental results.

c. Protective ring: There should be a protective ring together with the

holders to prevent leakage as an optional use.

d. Pressure indicator or manometer: The experimental part connected to

the test head that can measure at least 2% accuracy for showing the

pressure drop for 50 Pa, 100 Pa, 200 Pa or 500 Pa during the experimental

area.

e. A device for creating a smooth air stream: The proper air flow to supply

a pressure drop 50 Pa and 500 Pa between the test piece on all sides of

the test piece holder, the controlled temperature and humidity.

f. Flowing measurer volumetric counter or measuring range of measures:

To determine the air velocity (Venturi) with a minimum accuracy of 2%

as cubic decimetre per minute.

Test Method

The method used here is ISO 9237.


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PROCEDURE

1. Preparing appropriate samples in accordance with standard for the air

permeability

2. Conditioning the samples

3. Setting the pressure and time of the air permeability test device in

accordance with the sample.

4. Placing the sample to the device

5. Running the device

6. Reading the value of air permeability of the sample from the indicator

of the device at the end of the test.

7. After taking the arithmetic mean of the test results, to calculate the

value of air permeability.

8. Repeating the test for the appropriate number of samples in accordance

with standard.

Test piece is kept to a circular sample holder by being careful not to

interfere in the plane of the fabric itself, by applying sufficient voltage if

any wrinkles are available. It is necessary to avoid from the wrinkled places

and the edges. As the air permeability of the fabric may be different on

both side of it, the fabric face subjected to the experiment should be stated

in the experiment report.

For applying air flow towards the test part, air extractor or other vehicles

are switched on and as suggested above, an air flow is adjusted until a

pressure drop is created in the part of the fabric subjected to experiment.After reaching a minimum of one minute or stabilize the air flow is

recorded. Under the same experimental conditions, , the experiment is

repeated at least 10 times in different parts of the sample. Finally, taking

the arithmetic mean of the test results, the value of air permeability is

calculated.


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The experiment Result

Air permeability (R) is calculated as mm / s by using the following

equation.

167*A

qR V

Vq : The arithmetic average of the air flow rate, dm3/minute (or l / min),

A: The fabric area subjected to the test, cm3,

167: dm3 / (min x cm2) units of mm / s volume conversion factor for the

transition

Shrinkage test

Test Method ISO 6330.

For this test 2 pieces of sample of 50cmx50cm sample fabric is taken. Then

they are kept together and sewn overlock stitch on 3 sides. Then bench

marks are given by a template of 35cmX35cm as shown on the figure. Now

it is washed in a washcator at 40 degree celcius with 22 liter water ECE

detergent and 22 gm sodium perborate. Then it goes to tumble dryer. Here

it is dried below 70 degree celcius until it gets dry. After drying it is

conditioned for 4 hours in the conditioning room. Then the measurement is

taken in wales and coursewise.


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50cm

35cm

35cm

50cm

Fig : Sample dimension for shrinkage test

Bursting strength

Test Standard ISO 13938-2 1999

Machine name: TruBurst Model 610

Manufactured by James H Heal & Co. Ltd.

It is a pneumatic type bursting strength tester.

Technical data of the machine:

Range: 1000 kPa

Machine S/N 610/06/4054


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Software V1.08

Machine parameter for the test:

Test Area 50cm

Clamping -- 6.0 Bar

Pressure Rate 10 kPa/s

Pressure Drop10 kPa

Diaphragm --1.0mm Duraflex

Correction rate 2 kPa/s

Correction -35.2 kPa @ 46.1mm

Three samples are taken. They are clamped over an expansive diaphragm by

means of a circular clamping ring. Increasing compressed air pressure is applied to

the underside of the diaphragm, causing distension of the diaphragm and the

fabric. The pressure is increased smoothly untile the test specimenburst. The

burst strength is then determined by subtracting the diaphragm pressure from

the mean bursting pressure.

Here, bursting pressure is the maximum pressure applied to a test specimen

clamped overran underlying until the test specimen rupture

&

Diaphragm pressure is the pressure applied to the diaphragm, with no test

specimen present, to distend it to the mean bursting distension of the test

specimen.


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Spirality test

Test Standard AATCC 179

Test Procedure

From the same sample tested for shrinkage test is taken. Now the length of left

and right seam is measured and calculated the average value for precision result.

Now the distortion of the widths of the bag at the open end is measured. It is

done at both end and calculated the average for the precision of the value. Now

the spirality can be measured from the following equation,

Distortion

Spirality = X 100 %

Length


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Chapter 4

Results & Discussion


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GSM calculation

Table 1: Sample no 1(a): 100% cotton single jersey 30 Ne

Serial

no

Test

property

Reading Average

result

Remarks

(if any)01 02 03 04 0501 Fabric

weight

G/m2

131.6 131.6 134.3 134.2 132.2 132.8 GSM

Table 2: Sample no 1(b): 30/1 cotton (96%) and 20D Lycra (4%) S/J (Full feeder)

Serial

no

Test

property

Reading Average

result

Remarks

(if any)01 02 03 04 0501 Fabric

weight

G/m2

182.1 181.0 182.4 183.0 183.6 182.4 GSM

Table 3: Comparison among these two samples based on GSM

Sample no. Fabric

weight(gm/m2)

Standard

deviation

CV%

1(a) 132.8 1.22 0.92

1(b) 182.4 0.88 0.48


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Chart 1: representation of Fabric weight

Chart 2: Representation of standard deviation

0

20

40

60

80

100

120

140

160

180

200

1(a) 1(b)

Fabric weight(gm/m2)

Fabric weight(gm/m2)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1(a) 1(b)

Standard deviation

Standard deviation


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Chart 3: representation of CV%

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1(a) 1(b)

CV%

CV%


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Wales/cm and course/cm calculationTable 4: Sample no 1(a): 100% cotton single jersey 30/1 Ne

Serial no Wales/cm Wales/cm(avg.) Course/cm Course/cm(avg.)

1. 38

37

54

52

2. 36 52

3. 35 51

4. 37 53

5. 39 50

Table 5: Sample no 1(b): 30/1 cotton (96%) and 20D Lycra (4%) S/J (full feeder)

Serial no Wales/cm Wales/cm

(avg.)

Course/cm Course/cm(avg.)

1. 42

40

57

59

2. 40 59

3. 38 61

4. 39 58

5. 41 60

Table 6: Comparison among these two samples based on Wales / cm and

Course/cm:

Sample no Wales/cm Course/cm

1(a) 37 52

1(b) 40 59


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Chart 4: Representation of Wales per cm

Chart 5: Representation of Course per cm

35.5

36

36.5

37

37.5

38

38.5

39

39.5

40

40.5

1(a) 1(b)

Wales/cm

Wales/cm

48

50

52

54

56

58

60

1(a) 1(b)

Course/cm

Course/cm


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Course Spacing & Wales Spacing Calculation

Table 7: Sample no 1(a): 100% cotton single jersey 30/1 Ne

Serial no Wales spacing

w(mm)

Wales spacing

(avg.)

Course

spacing c(mm)

Course

spacing (avg.)

1. 0.26

0.27

0.19

0.19

2. 0.28 0.19

3. 0.29 0.2

4. 0.27 0.19

5. 0.26 0.2


Serial no Wales spacingw(mm) Wales spacing(avg.) Coursespacing c(mm) Coursespacing (avg.)

1. 0.24

0.25

0.18

0.17

2. 0.25 0.17

3. 0.26 0.16

4. 0.26 0.17

5. 0.24 0.16

Table 9: Comparison among these two samples based on Wales / cm andCourse/cm:

Sample no Wales Spacing Course Spacing

1(a) 0.27 0.19

1(b) 0.25 0.17


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Chart 6: representation of wales spacing

Chart 7: Representation of Course spacing

0.24

0.245

0.25

0.255

0.26

0.265

0.27

0.275

1(a) 2(b)

wales spacing w(mm)

wales spacing w(mm)

0.16

0.165

0.17

0.175

0.18

0.185

0.19

0.195

1(a) 2(b)

course spacing c(mm)

course spacing c(mm)


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32

Stitch Density

Table 10: calculation of stitch density

Sample Wales/cm Course/cm Stitch

density=wpcXcpc

cm2

1(a) 37 52 19241(b) 40 59 2360

Chart 8: representation of Stitch Density

0

500

1000

1500

2000

2500

1(a) 1(b)

Stitch Density (cm2)

Stitch Density (cm2)


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33

ICI Pilling test reportTable 11: Sample no 1(a): 100% cotton single jersey 30 Ne

Serial no. No. ofcycles Rating inWales

direction

Avg. ratingin Wales

direction

Coursedirection Avg. ratingin Course

direction

1. 14400 4 4 4 4

2. 14400 4 4


Serial no. No. of

cycles

Rating in

Wales

direction

Avg. rating

in Wales

direction

Course

direction

Avg. rating

in Course

direction

1. 14400 4 4 4 4

2. 14400 4 4

Comparison among these two samples based on ICI Pilling test:

Sincere observation on above tabulated value obtained from ICI Pilling test shows

that rating is not influenced by the use of Elastane as an Elastane yarn.


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34

Shrinkage test

Table 13: Sample no 1(a): 100% cotton single jersey 30/1 Ne

Serial no. Direction Original

length(cm)

Length after

wash (cm)

Shrinkage%

01. Length 35.00 33.20 -5.1

02. Width 35.00 33.40 -4.6


Serial no. Direction Originallength(cm)

Length afterwash (cm)

Shrinkage%

01. Length 35.00 33.60 -4.0

02. Width 35.00 34.30 -2.0

Table 15: Observation shows that using elastane yarn can reduce the shrinkage

percentage.

Sample no. Shrinkage in lengthdirection

Shrinkage in widthdirection

1(a). -5.1 -4.6

1(b). -4.0 -2.0


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35

Chart 9: Representation of shrinkage test

-6

-5

-4

-3

-2

-1

0

Shrinkage in length direction Shrinkage in width direction

1(a).

1(b).


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36

Bursting strength testTable 16: Sample no 1(a): 100% cotton single jersey 30/1 Ne

Serial no. Bursting strength(K Pa) Burstingdistension (mm) Bursting Time (s)

01. 116.7 30.0 15

02. 122.8 30.3 15

03. 132.6 30.8 17

Table 17: Mean value of bursting strength

Mean 124.1 30.4 15.7

Co efficient of

Variation( CV% )

6.45 1.37 7.37


Serial no. Bursting strength

(K Pa)

Bursting

distension (mm)

Bursting Time (s)

01. 151.2 45.2 19

02. 143.3 45.7 18

03. 144.3 45.5 18

Table 19: Mean value of Bursting strength

Mean 146.3 45.5 18.3

Co efficient of

variation

( CV% )

2.91 0.54 3.15


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Table 20: Comparison between these two samples

Sample no. Bursting strength

(K N/m2)

CV% of bursting strength

1(a). 124.1 6.45

1(b). 146.3 2.91

Chart 10: Bursting strength

Chart 11: Representation of CV% of bursting strength

110

115

120

125

130

135

140

145

150

1(a). 1(b).

Bursting strength (K N/m2)

Bursting strength (K

N/m2)

0

1

2

3

4

5

6

7

1(a). 1(b).




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38

Air Permeability test

Table 21: air permeability test resultsSample type Obs. 1 Obs. 2 Obs. 3 Obs. 4 Obs. 5 Average

Valuel/m2/s

100%cotton 662.6 664.6 663.3 663.9 663.6 663.6

Cotton/elastane 30.1 31.1 30.4 30.8 30.6 30.6

Chart 12: Representation of Air Permeability

0

100

200

300

400

500

600

700

100% cotton cotton/ elastane

Air permeability (l/m2/s)

air permeability l/m2/s


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39

Spirality Test:

Table 22: Spirality test result

Sample Spirality(%)100% cotton 1.1Cotton/elastane 1.9

Chart 13: Representation of spirality results

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

100% cotton cotton/elastane

spirality (%)

spirality (%)


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40

Stitch length:

Table 23: stitch length result

Sample Obs. 1 Obs. 2 Obs. 3 Obs. 4 Obs. 5 Avg. Stitch

length(mm)100%cotton

3.02 3.03 3.00 3.01 2.99 3.01

Cotton/elastane

2.98 2.97 2.99 2.99 2.97 2.98

Chart 14: Representation of stitch length

2.965

2.97

2.975

2.98

2.985

2.99

2.995

3

3.005

3.01

3.015

100% cotton cotton/elastane


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41

Discussion

The weight of the samples increase as the loop length decreases or the

amount of elastane increases, because the greater the amount of elastane,

the tighter the fabric.

Air permeability is lower for full feeder cotton/elastane fabrics and greatest

for cotton samples, because tighter fabrics are obtained with elastane in

the knitted structures. The difference between the air permeability values

of these two samples is consistently higher. The variation in air

permeability values of samples knitted from cotton yarn is significantly high

in accordance with loop length. But for full feeder samples, there are no

important changes related to loop length.

The pilling grades of both the samples are same. Therefore, presence of

elastane doesnt affect the pilling property.

The percentage of spirality, is greater in cotton/spandex fabric.

The course spacing is less in the full feeder fabric because of reduction of

loop length. it is same in wales spacing.

Course per cm & wales per cm increases in the cotton/elastane fabricbecause of reduction of loop length. As a result Stitch density increases in

cotton/elastane fabric.

Bursting strength of cotton/elastane fabric is higher than the 100% cotton

s/j. Because the use of elastane helps the fabric to expand more than the

100% cotton s/j and it needs more pressure and more time to burst the

sample.

The shrinkage percentage of cotton/elastane fabric is less than the 100%

cotton s/j fabric. Because elastanefibre helps to retain the fabrics original

dimension as far as possible after washing.


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Chapter 5

Conclusion


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44

Literature Cited

[1] Schulze, U. (1993), Rechts/Links-Rundstrick-Bindungen nDurKombinationmitDorlastan, Wirkerei und Strickerei Tech., 5, p: 456.

[2]Ceken, F., 1995, Some Investigations of the Dimensional Properties of KnittedFabrics Containing Different Materials, Doctoral thesis,

Ege University, Izmir.

[3]Tasmaci, M., 1996, Effects of Spandex Yarn on Single Jersey Fabrics Knittedwith Naked Lycra Yarn, TekstilveKonfeksiyon, 6, p: 422-426.

[4]Meri B., Grarda A., Proceeding of TheXIIth Textile and Leather Romanian

Conference, October 2002, pp. 17-19.[5]Marmaral, A., 2003, Dimensional and Physical Properties of Cotton /SpandexSingle Jersey Fabrics, Textile Research Journal, 73(1), p: 11-14.

[6]Marmaral, A., zdil, N. and DnmezKretzschmar, S., 2006, Thermal Comfortand Elastic Knitted Fabrics, International Conf. CIRAT- 2, Monastir-Tunisia.

[7] Baozhu, K., Weiyuan, Z., "The optimal design of three-layer plated fabrics",Fibres& Textiles in Eastern Europe, 15, 2007, 59-61.

[8] Bruer, S. M., Powell, M., Smith, G., "Threedimensionally knit spacer fabrics: areview of production techniques", Journal of Textile and Apparel, Technology andManagement, 4, 2005, 1-31.

[9] Cuden, A. P., Srdjak, M., Pelko, H., "Optimization of the cotton/Lycra plainknitted Fabric parameters", International Journal of Polymeric Materials, 47, 2000,633648.

[10] zdil, N., "Stretch and Bagging Properties of Denim Fabrics Containing

Different Rates of Elastane", Fibres and Textiles in Eastern Europe, 1, 2008, 63-67.

[11] Gorjanc, S., Bukosek V., "The behaviour of fabric with elastane yarn duringstretching, Fibres and Textiles in Eastern Europe, 3, 2008, 63-68.


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[i] Grunfeld, A. J., "Knit fabric with elastic combination yarn", US Patent5198288, 1993.

[ii] Bon M.,"Method for making patterned plated knit fabric", European Patent1006822, 1998.

[iii] Sangiacomo F., "Method for making patterned plated knit fabric", US Patent6715325, 2004.

[iv] Miller, R. A., Atkins, J. D., Rummel, D. R., " Cotton jersey fabric constructionhaving improved stretch characteristics", US Patent 7040124, 2006

[v] Pfangen, T., "Finishing of woven and knitted fabrics with elastane fibers",Asian Textile Business, 585, 2003, 46-51.

[vi] Iyer, C., Mammel, B., Schach, W., "Circular Knitting", Meisenbach GmbH,Bamberg, Germany, ISBN 3-87525-066-4, 1995.

[vii] "Dorlastanin circular knitting", Dorlastanproduct information technical report,Asahi Kasei Spandex Europe GmbH, Germany, 2008.

Books

Jerde, Judith.Encyclopedia of Textiles. Facts on File, 1992.

Lewin, M. and J. Preston, ed.High Technology Fibers. New York: Marcel Dekker,1985.

Other

iv. Devra, A. U.S. Patent 5,303, 882, 1994.Goodrich, C & W. Evans. U.S. Patent 5,028,642, 1991.

[Article by: Perry Romanowski].

v.

Bayazit, A., Introduction to Weft knitting, EgeUniv..TkaumYayin No.9,Izmir, 2000.

vi. Ceken. F., Some Investigations of the dimensional properties of knitted offabrics containing different materials. Doctoral thesis, EgeUniv. Izmir.

1995.


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Websites:

1.www.asahi-kasei.co.jp/fibers/en/roica/index.html.2.www.creora.com.3.www.dorlastan.de.4.www.elaspan.com.5.www.fillattice.it.6.www.fujibo.co.jp.7.www.invista.com.8.www.lycra.com.9.www.pegaheo.com/sheiflex.htm.
http://www.asahi-kasei.co.jp/fibers/en/roica/index.htmlhttp://www.creora.com/http://www.dorlastan.de/http://www.elaspan.com/http://www.fillattice.it/http://www.fujibo.co.jp/http://www.invista.com/http://www.lycra.com/http://www.pegaheo.com/sheiflex.htmhttp://www.pegaheo.com/sheiflex.htmhttp://www.pegaheo.com/sheiflex.htmhttp://www.lycra.com/http://www.invista.com/http://www.fujibo.co.jp/http://www.fillattice.it/http://www.elaspan.com/http://www.dorlastan.de/http://www.creora.com/http://www.asahi-kasei.co.jp/fibers/en/roica/index.html

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