project work group

Chapter-01Introduction

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1.Introduction

The ever increasing demand of knitted apparels has attracted attention in global niche market. In comparison to woven garment, around 50% of the clothing needs are met by the knitted goods. It is well known that weft knitted fabrics tend to undergo certain dimensional changes that causes distortion in which there is a tendency of the knitted loops to bend over, causing the wales to be at diagonal instead of perpendicular to the courses.

Spirality of knitted fabric is obtained when the wale is not perpendicular to the course, forming an angle of spirality with vertical direction of the fabric. It affects particularly single jersey fabrics and presents a serious problem during garment confection and use. The t-shirt production, for example, suffers from many quality problems linked to fabric spirality such as mismatched patterns, sewing difficulties, displacement of side seam to the back and front of the body and garment distortion. Spirality has an evident influence on garment aesthetics. The spirality phenomenon concerns essentially unbalanced structures such as single jersey fabrics. The symmetry of rib structures reduces considerably the spirality. Unset yarns under low tensile loads have a tendency to return to their untwisted state.

This project proposed to measure spirality angle of cotton plain knitted fabric by manually technique with protector at finished stage. This project work have also investigate the effect of fabric and machine parameters such as wales per inch, loop length, course per inch and count on fabric spirality.

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1.1.Objective of The Study1. To understand the effects of different parameters on spirality.2. Determination the effects of different parameters on spirality.3. To relate the relations among studied parameters.4. To know the effect the spirality on weft knitted fabric.5. To know the causes of spirality and their effect.

1.2. Organization of The Project WorkFariha Knit Tex. Ltd.(A Composite knitting oriented Factory)Address: Baroybogh, Enayetnagr, Fatullah, Narayanganj, Bangladesh.Fax Number: + 880 – 2 – 8813542E–mail Address: [email protected]

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Chapter-02Literature Review

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2. Literature Review

2.1.Yarn CountThe count of a yarn is a numerical expression which indicates its fineness or coarseness. i.e. whether the yarn is thin or thick.

According to Textile Institute, yarn count is a number indicating mass/unit length or length/unit mass of yarn.

Systems of yarn Count:

We have two systems of yarn count

1. Direct System(Mass/Unit length or Weight/Unit length)2. Indirect system(Length/unit mass or length/unit weight)

Table-1: Table of Direct System

Direct system of yarn count Weight Unit Unit length

Tex gm. 1000m.

Denier gm. 9000m.

lbs/Spyndle lbs. 14400m.

In Direct system if the No. of yarn count is increase, yarn fineness is decrease.

Table-2: Table of Indirect System

Indirect system of yarn

count

Length Unit Unit Weight

Ne(English Count) 840 yds. 1 lb.

Nm(Metric Count) 1000m. 1 kg.

Nw(Worsted Count) 560 yds. 1 lb.

In Indirect system if the No. of yarn count is increase, yarn fineness is also increase.

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2.2 Single jersey

The weft knitted fabric produce with one set of needles (both in tubular or flat forms) are called as single jersey or plain knit fabric. The structure is produced When all the needles of a single bed machine knit a each feed .The structure can be of technical face or technical back.

Figure-1:The technical face & back of plain knitted fabric

2.3 Feature of single jersey structure

1.Face side and back side of fabric are different.2. Curl or roll of fabric occurs at the edges.3. Wales are clearly visible on the face side of the fabric.4. Extensibility in widthwise is approximately twice than length.5 .Unraveling of fabric occurs from either side is possible.6. Thickness of fabric is approximately twice the diameter of yarn used.7. There is only one series of knitted loop per courses in the fabric.

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http://textilelearner.blogspot.com/2012/01/carpet-thickness-tester-working.html

2.4.Course

The row of loops or stitches running across the width of a fabric corresponding to filling of a knitted fabric.

Figure-2: course of knitted fabric

Numbers of course per inch in knitted fabric is called CPI (course per inch

2.5. Wale

In knit fabrics, a column of loops running lengthwise the fabric.

Figure-3: wales in knitted fabric

Numbers of wales per inch in knitted fabric is WPI (wales per inch)

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2.6.Stitch length

Distance from a point of a knit loop to the same point of subsequent loop is called stitch

length.

Figure-4: An ideal loop

2.7.Spirality"Spirality" arises from twist stress in the constituents yams of plain fabric, causing all

loops to distort and throwing the fabric wales and courses into an angular relationship

other than 90 degree.

Figure-5: Ideal knit structure

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Figure-6: Spirality of wale Figure-7: Spirality of course

2.8.Causes of Spirality

There are different types of causes for occurring fabric spirlity. Course spirality is a very common inherent problem in plain knitted fabrics. The following are some predominant causes of spirality in knitted fabrics.

1. Yarn twist multiplier is the principle cause of spirality and it is directly proportional.

2. Residual torque in the yarn or the twist liveliness. 3. Spirality occurs in knitted fabric because of asymmetric loops which turns in the

wales and course of a fabric into an angular relationship other than 90 degree. 4. Number of feeders-though higher feeder numbers increases production, spirality

also increased. 5. Different spinning technologies such as ring, rotor, airjet etc., also influence

spirality. The physical properties of these yarns, their geometrical characteristics, their basic fibre properties (i.e. modules, fineness, cross section etc.) and blends are the causes.

6. Variation in knitting tension, yarn frictional properties, yarn/metal coefficient of friction, yarn lubrication, number of contact points in the knitting zone i.e. needles and sinkers) also influence spirality.

7. Washing wet treatments increases fabric relaxation and also increases spirality. 8. Direction of machine rotation has little influence on spirality. Slight inclination of

loops occurs in the direction of machine rotation. Multifeed machines rotating clockwise produce spirality to the left and machines rotating anti clock wise produce spirality to the right.

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Figure shows the various causes of fabric spirality and they are divided into four main categories: yarn causes, knit causes, fiber causes, and finishing causes

2.8.1. Spirality for fiber

1. Fiber typesDifferent fibers have different properties like absorbency and elastic recovery vary fiber to fiber, which have a great impact on fiber relaxation after knit.

2. Flexural rigidityIt is the property of fiber against flex or bend. It influences the straighten affinity of fiber from bend form.

3. Torsion rigidityIt is the property of fiber against torsion force. It influences detwist force of fiber or yarn.

4. Fiber finenessWith increase of fiber fineness twistability of increase. So it is an important factor for detwist force.

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5. Fiber lengthFiber length has an effect on bending property of fiber.

6. BlendIn general, 50/50 cotton/polyester blends have a lower tendency to produce spirality in fabrics than the 100% cotton yarns. Spirality can be virtually eliminated by using 50/50 cotton/polyesters blend of air jet and rotor yarns.

2.8.2. Spirality for yarn1.Count

Degree of freedom of yarn movement in the fabric structure contributes significantly to the increase in spirality. Dimensional parameters of fully relaxed single jersey fabrics depend on the yarn linear density and tightness of construction. If diameter is reduced, its resistance to deformation is lowered. It indicates that, deformation of loop structure is influenced by yarn count. In other words, the finer the yarn, the more will be the spirality due to more twisting.\

2.Twist

Usually in knitting, low twisted yarns are used. High twisted yarn has a great impact on spirality due to its unrelieved torque. With the increase in twist, the twist liveliness increases, this in turn, causes the angle of spirality to increase. The direction of spirality in the fabrics knitted from short staple ring spun single yarns is determined by the yarn twist direction. Thus, the technical face of single jersey fabric exhibits spirality in the Z direction if a Z twisted yarn is knitted.

Figure-8 : types of twist

3. Yarn Twist Multiplier (TM)This index is represented by the following formula:TM = T.P.I. / √N, where T.P.I. indicates twist per inch and N represents yarn number in an indirect system, the cotton system unless otherwise specified. With the increase in twist multiplier, the angle of spirality increases.

4. Yarn Twist Factor (TF)TF is related with the following formula:TF = TPCm x √ T, where T signifies yarn number in Tex.

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Raising the twist factor of two ply yarn increases the left hand or S-direction spirality, whereas increasing the twist factor of single yarn increases the right hand or Z-direction spirality.

5. ConditioningThe minimum Spirality level that can be achieved by several ways such as storing yarn at appropriate temperature and relative humidity or by thermal conditioning with low temperature saturated steam in vacuum that results in a speedy relaxation. This process balances the twist so that it does not regain its original state. However, there is no systematic study carried out to understand the effect of yarn conditioning on spirality of single jersey fabrics.

6. Spinning methodYarn produced by different spinning technique has a direct bearing on spirality of knitted fabric. Friction spun yarn made of 100% cotton produce fabrics with highest degree of spirality, followed by ring spun yarns. Both rotor spun and air jet yarns produce fabrics with a low degree of spirality.

7. Yarn bulkinessYarn bulkiness increase compactness of fabric, which make loops immobilize in fabric.

8. Twist levelHigher the TPI higher detwist force act per inch of yarn.

9. Mechanical propertiesMechanical properties like young’s modulus, elastic recovery, tenacity etc. of yarn influence the spirality of fabric.

2.8.3. Spirality for fabric1. Fabric stitch length

This is the length of one loop in knitted fabric. Spirality increases with the length of loop.

2. Fabric structureMore spirality in single jersey due to non-arrest of loops. By adding moisture to such a structure, the twist will try to revert as it swells, that distorts the shape of the loop. In double jersey, the effect of spirality is nullified. Pique and honey comb also show

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spirality even if sometimes two beds are used. Spirality can be noticed in certain jacquard structures. In stripe pattern, it increases with the size. No appreciable problem of spirality is there in ribs and interlocks.

3. Tightness Slack fabric presents higher spirality angle compared to tightly knitted fabrics. At each level of yarn twist factor, the degree of spirality decreases linearly with fabric tightness factor.

4. Fabric relaxation Fabric relaxation (dry and wet) treatment removes the residual knitting tension in the yarn introduced during the knitting process. The relaxation treatment relieves the residual yarn torque as a result of changes in the molecular structure and increasing yarn mobility.

2.8.4. Spirality for machine

1. Number of feeders The number of feeders in a circular knitting machine also influences the angle of spirality. Due to more course inclination, spirality will be more.

2. Direction of machine rotation The direction of machine rotation has influence on spirality. For Z twist yarns, the wales go to the right and thus, giving Z skew and S twist yarns makes the wales go to the left, giving S skew to the fabric. With multi feed machines, the fabric is created in helix, which gives rise to course inclination and consequently wale spirality. Direction of spirality depends on the rotational direction of the knitting machine. Earlier research work revealed that, for a clockwise rotating machine, the wale would be inclined towards the left, thus producing the S spirality

3. Gauge In knitting terminology, number of needles per inch is called the gauge. Smaller the gauge, lesser will be the spirality keeping other parameters constant. A proper combination of linear density and gauge is required to reduce spirality e.g. torque can be controlled in 20 gauge and 40s count.

4. Knitting tension The effects of various knitting tensions including the whole process of loop formation on fabric spirality had been could not establish consistent trends with respect to variations in fabric quality with knitting tensions. The twist factors of ply and single yarn, loop length, and fiber diameter have significant effects on the angle of spirality, while yarn linear density and fabric tightness factor have comparatively lesser effect. So that it is clearly show that the spirality angle is reduced to a certain level with the other parameters are keep constant.

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Figure-9: Spirality of weft knitted fabric

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Chapter-03Methodology

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3.1. Methodology

We collected 9 sample of single jersey weft knitted plain fabric.

We count number of wales widthwise in 10 inch of fabric by means of counting glass and needle then divided the result by 10 to find out the WPI. We took 5 readings and average the value to find average value of WPI of a sample. In same way we calculate the WPI of all samples.We count number of course lengthwise in 10 inch of fabric by means of counting glass and needle then divided the result by 10 to find out the CPI. We took 5 readings and average the value to find average value of CPI of a sample. In same way we calculate the CPI of all samples.We use “ISO 16322-2, Textiles — Determination of spirality after laundering.” method for the measurement of spirality.We normally wash the samples in washing machine and measure as follows.In term of angle measurement, marked a wales then measured angle between a course and marked wale by means of a protractor. We carefully took 5 readings for “angle of spirality” of all 9 samples. Then average the value of 5 angles to get average “angle of spirality”.

To measure the stitch length, at first we count 100 wales and marked it very well as if after opening of the yarn the mark can be seen. Then we open the 100 wales stretch it and took the length of 100 wales .Then we divide the number by 100 to get the stitch length. We average the 5 values to get average stitch length of each sample.To measure count we took 20 yarns of length 12 inch from each sample and weight them by means of electrical scale. We took 20 samples of 12 inch yarn which in total 240 inch or 6.67 yds of yarn. We did this operation for five times for each sample. We recorded the weight of each sample carefully. We put the values of length and weight in following equation to find out the yarn count.

N = (L × w) / (l × W)

Where,N = yarn countL = length of sampleW = the weight of the sample at the official regain in the units of the system l =the unit length of the system w= the unit weight of the systemWe average 5 counts to get average count of a sample.

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Chapter-04Experimental

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4. Experimental

4.1. Analyzed data in tableWe have got following tables from our research on 9 samples.

Sample No.: 01

Table-3: Table for Wales Per Inch (WPI)

No of experiment Wales per 10 inch Wales per inch (WPI)

Wales per 10 inch/ 10

Average WPI∑WPI/ 5

01 330 33

32

02 320 32

03 330 33

04 320 32

05 320 32

Table-4: Table for Course Per Inch (CPI)

No of experiment Course per 10 inch Course per inch (CPI)

Course per 10 inch/ 10

Average CPI∑CPI/ 5

01 405 40.5

40

02 400 40

03 410 41

04 403 40.3

05 400 40

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Table-5: Table for Stitch Length (SL)

No of experiment

Linear length of yarn / 100

wales(x in mm)

No. of Wales(y)

Stitch length (SL) in mm

(x/y)

Average stitch length

01 274 100 2.74

2.7502 275 100 2.7503 271 100 2.7104 275 100 2.7505 275 100 2.75

Table-6: Table for Angle of Spirality

No of experiment Angel of spirality Average01 10°

9.5°02 8.5°03 9°04 10°05 9.8°

Table-7: Table for Count

No of experimen

t

Length of

sample L(yds)

Weight of the

sample W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002205

840 1 36 36

02 6.67 0.0002206

840 1 35.99

03 6.67 0.0002210

840 1 35.92

04 6.67 0.0002204

840 1 36.02

05 6.67 0.000220 840 1 36

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5

Sample No.: 02

Table- 8: Table for Wales Per Inch (WPI)




01 420 42

4202 421 42.103 422 42.204 420 4205 421 42.1





01 600 60

6002 605 60.503 604 60.404 600 6005 605 60.5

Table- 10: Table for Stitch Length (SL)

No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


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01 225 100 2.25

2.2402 224 100 2.2403 227 100 2.2704 224 100 2.2405 224 100 2.24



5°02 5.5°03 4.2°04 5.5°05 5°

Table-12:Table for Count

No of experimen

t

Length of

sample L(yds)

Weight of the sample

W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002646 840 1 30

3002 6.67 0.0002603 840 1 30.503 6.67 0.0002646 840 1 3004 6.67 0.0002561 840 1 30.505 6.67 0.0002545 840 1 31.2

Sample No.: 03





01 400 40 4002 405 40.5

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03 400 4004 395 39.505 390 39


No of experiment Course per 10 inch Course per inch (CPI)Course per 10 inch/ 10


01 510 51

5102 505 50.503 520 5204 510 5105 500 50


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 237 100 2.37

2.3802 238 100 2.3803 241 100 2.4104 239 100 2.3905 240 100 2.4


No of experiment Angel of spirality Average01 6° 5.2°

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02 5.5°03 5°04 5°05 4.5°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002512 840 1 31.61

3202 6.67 0.0002520 840 1 31.5003 6.67 0.0002518 840 1 31.5304 6.67 0.0002506 840 1 31.6805 6.67 0.0002510 840 1 31.63

Sample No: 04

Table- 18: Table for Wales Per Inch (WPI)




01 381 38.1

3802 385 38.503 384 38.404 378 37.805 380 38.0


No of experiment Course per 10 inch Course per inch Average CPI

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(CPI)Course per 10 inch/

10

∑CPI/ 5

01 485 48.5

4802 479 47.903 482 48.204 478 47.805 485 48.5


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 234 100 2.34

2.3002 231 100 2.3103 230 100 2.3004 230 100 2.3005 229 100 2.29

Table- 21: Table for Angle of Spirality


5°02 5°03 5°04 5.5°05 3.5°


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No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of

the system l

(yds)

Unit weight of the

system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0003467 840 1 22.9

2302 6.67 0.0003422 840 1 23.203 6.67 0.0003452 840 1 2304 6.67 0.0003407 840 1 23.305 6.67 0.0003452 840 1 23

Sample No.: 05





01 354 35.4

3502 352 35.203 351 35.104 368 34.805 355 35.5





01 440 44 4402 447 44.703 445 44.504 430 43

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05 440 44


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 260 100 2.60

2.5902 259 100 2.5903 258 100 2.5804 259 100 2.5905 261 100 2.61

Tabl-26: Table for Angle of Spirality

No of experiment Angel of spirality Average01 7.2°02 8.4°

8°03 8°04 7.8°05 7.5°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0003394 840 1 23.39

2302 6.67 0.0003380 840 1 23.4903 6.67 0.0003385 840 1 23.4504 6.67 0.0003400 840 1 23.3505 6.67 0.0003392 840 1 23.4

Sample No.: 06


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01 365 36.5

3702 370 37.003 369 36.904 371 37.105 374 37.4





01 452 45.2

4502 450 45.003 450 45.004 455 45.505 451 45.1


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 253 100 2.53

2.5002 248 100 2.4803 250 100 2.5004 248 100 2.4805 251 100 2.51

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Table-31: Table for Angle Of Spirality


7.5°02 7°03 7.5°04 8°05 7°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002821 840 1 28.14

2802 6.67 0.0002815 840 1 28.2003 6.67 0.0002820 840 1 28.1504 6.67 0.0002825 840 1 28.1005 6.67 0.0002830 840 1 28.05

Sample No. : 07





01 377 37.7

3802 380 38.003 378 37.804 378 37.805 376 37.6


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Average WPI∑CPI/ 5

01 470 47.0

4802 476 47.603 480 48.004 488 48.805 490 49.0


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 238 100 2.38

2.40

02 240 100 2.40

03 242 100 2.42

04 240 100 2.40

05 238 100 2.38



6°02 6°03 5.5°04 6°05 7°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W

Average count(Ne)

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(Ne)01 6.67 0.0003173 840 1 25.02

2502 6.67 0.0003165 840 1 25.0803 6.67 0.0003175 840 1 2504 6.67 0.0003183 840 1 24.9405 6.67 0.0003185 840 1 24.93

Sample No.: 08





01 364 36.4

3002 362 36.203 360 36.004 358 35.805 363 36.3





01 570 57

3602 546 54.603 528 52.804 555 55.505 548 54.8

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No of experiment

Linear length of yarn / 100 wales(x in mm)

No. of Wales (y)

Stitch length (SL) in mm(x/y)


01 281 100 2.81

2.8202 284 100 2.8403 281 100 2.8104 282 100 2.8205 282 100 2.82



11.5°02 9.5°03 8°04 9.5°05 11.5°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002197 840 1 36.14

3602 6.67 0.0002193 840 1 36.2003 6.67 0.000196 840 1 36.1504 6.67 0.0002199 840 1 36.1005 6.67 0.0002202 840 1 36.05

Sample No. : 09


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01 358 35.8

3602 360 36.003 356 35.604 357 35.705 361 36.1





01 423 42.3

4202 417 41.703 415 41.504 420 42.005 425 42.5


No of experiment


wales(x in mm)

No. of Wales(y)


(x/y)


01 261 100 2.61

2.6002 260 100 2.603 262 100 2.6204 261 100 2.6105 260 100 2.6

Table 46: Table for Angle of Spirality

No of experiment Angel of spirality Average

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01 7.5°

8°02 8.5°03 8°04 8°05 7.5°


No of experimen

t

Length of

sample L(yds)


W (lbs)

Unit length of the

system l(yds)

Unit weight of

the system w (lbs)

Count N =

L × wl × W(Ne)

Average count(Ne)

01 6.67 0.0002310 840 1 34.36

3402 6.67 0.0002369 840 1 33.5103 6.67 0.0002308 840 1 34.404 6.67 0.0003214 840 1 34.3105 6.67 0.0002309 840 1 34.38

4.2.Overview of all table

Table-48: Over view of all tables.

Sample no.

Wales per inch (WPI)

Course per inch (CPI)

Stitch length (SL)

Count Angel of

Spirality1 32 40 2.75 36 9.5°2 42 60 2.24 30 5°3 40 51 2.38 32 5.2°4 38 48 2.30 23 5°5 35 44 2.59 23 8°6 37 45 2.50 28 7.5°7 38 48 2.40 25 6°

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8 30 36 2.82 36 11.5°9 36 42 2.60 34 8°

Chapter-05Result and discussion

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5. Result and Discussion

5.1. Result of effect of WPI on spirality

Table-49: Effect of WPI on Spirality

Sample no. Wales per inch (WPI)

Angel of Spirality

1 32 9.5°2 42 5°3 40 5.2°4 38 5°5 35 8°6 37 7.5°7 38 6°8 30 11.5°9 36 8°

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Figure-10: Effect of WPI on Spirality

5.1.1. Discussion

From above table 49 and its graphical Figure 10 it is seen that when the WPI is 30 the fabric spirality is 11.5° and when WPI is 42 spirality s 5°. In the full chart where WPI is decrease the spirality increase again where WPI increase the spirality decrease. Because when the wales number in inch is less, it gets more space to deflect from its position and form spirality. So it can be said that spirality increase with the decrease of WPI.

5.2. Result of effect of CPI on Spirality

Table-50: Effect of CPI on Spirality

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Figure-11: Effect of CPI on Spirality

5.2.1. Discussion

When density of the fabric is more than spirality can’t grow. The more number of course in an inch the density increase. As usual spirality will be less as simple. The above table and chat also shows the theory. Here, when the CPI is 36 the spirality is highest and for the highest CPI 60 the spirality is 5° which is lowest in the chart. So, the spirality increases with the decreasing number of CPI in the knit fabric.

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Sample no. Course per inch (CPI)

Angel of Spirality

1 40 9.5°

2 60 5°

3 51 5.2°

4 48 5°

5 44 8°

6 45 7.5°

7 48 6°

8 36 11.5°

9 42 8°

5.3. Result of effect of Stitch length on spirality

Table-51: Effect of Stitch length (SL) on Spirality

Sample no. Stitch length (SL)

Angel of Spirality

1 2.75 9.5°

2 2.24 5°

3 2.38 5.2°

4 2.30 5°

5 2.59 8°

6 2.50 7.5°

7 2.40 6°

8 2.82 11.5°

9 2.60 8°

Figure-12: Effect of Stitch Length on Spirality

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5.3.1. Discussion

From the table 49 and figure 12 we find that with the increase of stitch length spirality increases. Ftom table 49 we see that when the stitch length is 2.82 the spirality is higher. Spirality decreases with the decrease of stitch length.

5.4 Result of effect of count on spiraliity

Table-52: Effect of Count on Spirality

Sample no. Count Angel of Spirality

1 36 9.5°

2 30 5°

3 32 5.2°

4 23 5°

5 23 8°

6 28 7.5°

7 25 6°

8 36 11.5°

9 34 8°

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Figure- 13: Effect of Count on Spirality

5.4.1 Discussion

We know that in indirect system increase on count number express that the yarn is fine. So.knitting with finer yarn makes a light fabric. Fine yarn easily distort from its position than a courser yarn and we can easily say that finer the yarn spirality increases. In the table 50 and figure 13 also shows the relation. It is found that with the finer count of yarn spirality increases.

5.5.Final overview in graphical representation

1 2 3 4 5 6 7 8 90

10

20

30

40

50

60

70

Effect of WPI, CPI, Stitch Length. Yarn Count on spirality

Wales per inch (WPI)Course per inch (CPI)Stitch length (SL)CountAngel of Spirality

Figure-14:Effect of WPI, CPI, Stitch Length. Yarn Count on spirality

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5.5.1 Discussion on final overview of the resultWe have found the effects of four parameters (WPI, CPI, SL and Count) on Angle of Spirality. We have found four different count groups from 9 samples.

1. Theoretically, Spirality increases with the decrease of WPI. From table 47 and figure 10 we have found the same relation. From figure 10 we can see that with increase of WPI, Angle of Spirality decrease. That’s mean with the higher WPI, Spirality is lower.

2. From table 48 and figure 11 we can see that with increase of CPI, Angle of Spirality decrease. That’s mean with the higher CPI, Spirality is lower.

3. According to previous researches, Spirality increases with increase of Stitch Length (SL). This is because when stitch is higher than loop bent more freely due to torsional force during relaxation. As a result Spirality increases with higher Stitch Length (SL). In our research, we have found the effect of Stitch Length (SL) on weft knitted fabric unpredictable. This is because, we have worked with samples having nearer Stitch Length (SL) and since we have worked with samples of different Count, the effect of counts interrupt our result.

4. According to English System, the higher the count the finer the yarn. Theoretically, Spirality increases with count. This is because higher count indicates lower diameter. In structure, yarns of lower diameter can move more freely than that of higher diameter during relaxation. As a result, Spirality increases. From our research, we have found clear effect of Count on Spirality. From table 50 and figure 13 we can observe that Angle of Spirality decreases with count increase. Since Angle of Spirality inversely proportional to Spirality, hence Spirality increases.

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ConclusionTo know about the effect of WPI, CPI, Stitch Length, and Count on spirality is very important to make knit fabrics with better physical properties. Spirality could be a fault of knit fabrics. So, it make much wastage in fabrics. Where 80% garment cost depend on fabric costs. In cutting section it can make huge wastage of fabrics if it is not removed. To gather knowledge about the spirality is very important to minimize the wastage. So, the effects of such parameters like WPI, CPI, Stitch Length, and Count on spirality is very important. Sometimes spirality also happens for other parameters like machine guage, yarn twist, etc. Before going for bulk production such parameters should be taken carefully. For this purpose this research project will be helpful.

Through we feel the work somewhat unfinished due to lack of necessary arrangements for more work, but still the progress we’ve made on this matter should be taken into consideration.

Limitations

1. If we could work with more sample our result would be more accurate.2. We did some experiment manually, if we could do those experiments by the help

of automatic machine, it would be fine.3. If we could work in a lab it would be more helpful.

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References

Dr. N.Anbumani, “Knitting Fundamentals, Machine, Structures and Developments”, New Age International Pvt Ltd Publishers, 2007

David J Spencer, “ Knitting technology; a comprehensive handbook and Practical guide”, Woodhead Publishing Limited, 2012

Professor D.B .Ajgaonkar, “Knitting Technology”, Universal Publishing Corporation 2009

http://textilelearner.blogspot.com/2015/10/causes-of-spirality-testing-for-knitted.html#ixzz4BRNNC6wH

http://textilelearner.blogspot.com/2012/04/fabric-characteristics-characteristics.html#ixzz4BSWLMtMF

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project work group

Education