Arif 1(Spirility)

Page 1

Page 2

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.

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.

Ѳ

Type equation here.

Wales Wales

Courses Courses

Fig: Fabric with normal loop

position

Fig: Fabric with spirality

Ѳ =

dddddddddaAgn

Type equation here.

Angle of spirality

Page 3

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.

Theory of 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.

d

X

D/

X/

D

Y

Y

B/

B

ѲY

ѲF

ѲF

Normal to wale

line

Wale

A

L

ѲYF

Page 4

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=𝐶𝑜𝑢𝑟𝑠𝑒 𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡

𝐹𝑎𝑏𝑟𝑖𝑐 𝑊𝑖𝑑𝑡 ℎ=

𝐹

𝐶𝑛

𝑤

= 𝐹

𝐶×

𝑤

𝑛

Now, w=𝐾𝑤

𝑙 and c=

𝐾𝑐

𝑙 therefore, loop factor =

𝐾𝑐

𝐾𝑤=

𝑐

𝑤

tanѲF = 𝐹𝑤

𝑐𝑛=

𝐹

𝑛𝑅

Therefore, ѲF =tan-1

( 𝐹

𝑛𝑅)

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.

ѲY = angle of spirality due to yarn

ѲF = angle of spirality due to number of feeder.

ѲYF = total spirality

Page 5

Causes

The residual torque in the component yarn caused due to bending & twisting is

the most important phenomenon contributing to spirality. The residual torque is shown by

its twist liveness. Hence the greater the twist liveness, the greater the spirality. Twist

liveness of yarn is affected by the twist factor or twist multiplier. Besides the torque,

spirality is also governed by fiber parameters, x-section, yarn formation system, yarn

geometry, knit structure & fabric finishing. M/C parameters (no. of feeder, m/c gauge

etc.) also contributes to spirality. For instance, with multifeeder circular knitting m/cs,

course inclination will be more, thus exhibit spirality.

Influencing factors:

1) Count:

When the yarn dia reduces its resistance to deformation also decreases. 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:

(a) Twist multiplier:

We know, TM=TPI/√count

So when TM is increased, TPI also increased & the spirality of fabric also

increased.

TM Twist liveness(cm)

Spirality(degree)

3.2 19.69 4.2

3.5 25.99 6.5

3.8 28.96 7.3

(b) Twist factor:

We know, TF= TPcm × √tex

So, when TF is increased, TPcm also increased & spirality of

fabric also increased.

Page 6

(3) Conditioning:

Atmospheric temperature & humidity also greatly affects the spirality.

(4) Spinning method:

If yarn is produced in ring spinning system, that causes greater spirality than

produced in Rotor spinning & air spinning system.

(5) Blending of fibre:

100% cotton yarn shows more spirality than 50% polyester-cotton blend yarn.

(6) Fabric stitch length:

This is the length of one loop in knitted fabric, spirality increases with the

decreasing of stitch length.

(7) Fabric structure:

More spirality in s/j 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 multifeed pique & honey comb also show 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 & interlocks.

(8) Fabric 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.

(9) Fabric relaxation:

Fabric relaxation (dry & wet) treatment remover the residual knitting process. The

relaxation treatment relieves the residual yarn torque as a result of charges in the

molecular structure & increasing yarn mobility.

(10) M/C gauge:

In knitting terminology, no of needles per inches is called gauge. Smaller the

gauge lesser will be the spirality keeping other parameter constant. A proper combination

of linear density gauge is required to reduce spirality eg. Torque can be controlled in 20

gauge & 40’s count.

Page 7

(11) Knitting tension:

The effects of various knitting tension including the whole process of loop

formation on fabric spirality had been investigated by the researchers. Experimental

investigation could not establish consistent tends with respect to variations in fabric

quality with knitting tension.

The twist factor of ply &single yarn, loop length & fibre dia has significant effects

on the angle of spirality, while yarn linear density & fabric tightness factor have

comparatively lesser effect.

(12) Direction of m/c rotation:

Z-twist yarn gives z skew, s-twist gives s-skew to the fabric. With multifeed m/cs

, the fabric is created in helix, which gives rise to course inclination & consequently wale

spirality . Direction depends on the rotational direction of the knitting m/c. Earlier

research work revealed that, for a clockwise rotating m/c, the wale would be inclined

towards the left. Thus producing the spirality.

(13) Effect of fibre staple length:

In case of short staple fibre, cotton yarn liveliness is greater than viscose. So the

produced fabric spirality decreased with viscose yarn. The yarn with long staple length

has less spirality because of having less twist. For long staple fibre wool has less

liveliness than the acrylic fibre.

Page 8

(14) Effect of Ring & Rotor Yarn:

Spirality change between Ring & Rotor Yarn:

Dry

relaxed

state

Wet

relaxed

state

Washing

at 600C

Washing

at 800C

Washing

at 900C

Ring

Yarn

455

0.224

4.68 4.1 4.4 7.9 7.9

505

0.262

6.71 5.05 6.1 9.3 9.5

554

0.282

8.07 10.25 10.4 10.45 11

Rotor

Yarn

500

0.225

4.78 4.3 5.0 5.5 5.65

550

0.279

5.48 4.3 5.65 7.0 7.1

600

0.303

5.7 4.5 5.05 9 9.05

0

1

2

3

4

5

6

7

8

9

0.224 0.262 0.282

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Ring Yarn

0

1

2

3

4

5

6

0.224 0.279 0.303

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Rotor Yarn

Fig: Dry Relaxed State

Page 9

0

2

4

6

8

10

12

0.224 0.262 0.282

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Ring Yarn

0

1

2

3

4

5

6

7

8

9

0.225 0.279 0.303

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Rotor Yarn

0

1

2

3

4

5

6

7

8

9

0.224 0.262 0.282

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Ring Yarn

4.6

4.8

5

5.2

5.4

5.6

5.8

0.225 0.279 0.303

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Rotor Yarn

Fig: Washing at 600C

Fig: Wet Relaxed State

Page 10

0

2

4

6

8

10

12

0.224 0.262 0.282

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Ring Yarn

0

1

2

3

4

5

6

7

8

9

10

0.225 0.279 0.303

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Rotor Yarn

0

2

4

6

8

10

12

0.224 0.262 0.282

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Ring Yarn

0

1

2

3

4

5

6

7

8

9

10

0.225 0.279 0.303

Spir

alit

y A

ngl

e (

De

gre

e)

Loop Length (cm)

Rotor Yarn



Page 11

(15) Effect of combed or carded yarn:

In same count & TPI the carded yarn has more spirality than the combed yarn.

Because carded yarn needs more twist than the co9mbeed yarn.

(16) Effect of dyeing:

In case of dyeing with dark colors the spirality decreases and for light colors the

spirality will be increased.

(17) Effect of finishing:

Among the finishing machines, the stenter machine controls the form of spirality and this

control point is continued during compacting.

(18)Effect of clothing:

Spirality creates a big problem at the clothing step. It affects the garments as the

displacements of the side seam and this causes an important quality problem.

Determination of angle of wale 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 line 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.

Page 12

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.

Page 13

Page 14

Shrinkage

A dimensional change resulting in a decrease in the length or width of a specimen

subjected to specified conditions is known shrinkage. 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.

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

Page 15

Causes:

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.

Remedies:

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.

Page 16

Page 17

Method of spirality and shrinkage:

Method:

ISO-6330

Procedure:

a) two samples are taken; (62cm×62cm)

b) Three sides are sewing; one is open.

c) A measuring device (50cm×50cm); which put on the sample, draw a square

of(50cm×50cm) on the sample and 6cm is allowance from all sides.

d) These sample is taken for washing at 400C temp, in 45min and using

detergent(5g/l)

e) After washing the sample; it dries in Tumble Dry, Hang Dry and Flat Dry.

Calculation for spirality percentage:

Average deflection length from the seam line = X

Y= Sample length,

Spirality% = 𝑋

𝑌× 100

B A

D C

B A

D C/ C D/

Fig: Before Washing Fig: After Washing

Page 18

Example:

Average deflection, X = 2cm

Sample length, Y = 50cm

Spirality% = 2

50× 100 = 4%

As per the experience of world renowned retailers in the globe, seam twisting / shape

distortion / spirality greater than 6% in tops and shorts and 4% in skirts, pants, dresses,

and sleepwear detracts from the appearance of the garment.

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.

Page 19

Practical data:

Tumble dry

Single Jersey 120 GSM (Yarn Type: Cotton)

Sample No. Shrinkage

Twisting

maximum

(cm)

Spirality

Length wise Width wise

01 -4.5% -5% 2.8 5.6

02 -1.51% -4.16% 2.5 5

03 -0.74 -2.41 2 4

04 +.44 -3.92 2.4 4.8

05 0 -6.12 2.5 5


01 -7.4% -5% 2 4

02 -0.74 -2.09 2.3 4.6

03 -4 -4.9 1.9 3.8

04 -2.22 -3.92 1 2

05 -3.75 -0.99 1.8 3.6


01 -3.62 -1.96 1.5 3

02 -3.7 -0.96 1.3 2.6

03 -3.43 -6.06 1.7 3.4

04 -5.18 -4.12 1.4 2.8

05 0 -4 1.5 3

Page 20

0

1

2

3

4

5

6

120 GSM 130 GSM 140 GSM 160 GSM 180 GSM

Spir

alit

y (%

)

Single Jersey Fabric GSM (Cotton)


01 -0.72 -4 1 2

02 -3.67 -3.84 0.8 1.6

03 -1.17 -5.10 0.9 1.8

04 -2.14 -5.82 1.6 3.2

05 0 -3 1 2


01 -2.18 -4.73 0.5 1

02 0 -4.95 1.1 2.20

03 -4.83 -3.84 0.7 1.4

04 -1.17 -3.84 0.5 0.72

05 -0.72 -6.79 0.5 0.75

Fig: Relation between GSM & Spirality% (Tumble Dry)

Page 21

-8

-7

-6

-5

-4

-3

-2

-1

0

1

120 GSM 130GSM 140 GSM 160 GSM 180GSMs

h

r

i

n

k

a

g

e(

%)

i

n

L

e

n

g

t

h

w

i

s

e

single jersey fabric GSM(Cotton)

-8

-7

-6

-5

-4

-3

-2

-1

0


h

r

i

n

k

a

g

e(

%)i

n

W

i

d

t

h

w

i

s

e


Fig: Relation between GSM & Shrinkage% (Tumble Dry)

Page 22

Hang dry

Single Jersey 120GSM (Yarn Type: Cotton)


Twisting

maximum

(cm)

Spirality


01 -7.4% -5% 2 4

02 -0.74 -2.09 2.3 4.6

03 -4 -4.9 1.9 3.8

04 -2.22 -3.92 1 2

05 -3.75 -0.99 1.8 3.6


01 -3.62 -1.96 1.5 3

02 -3.7 -0.96 1.3 2.6

03 -3.43 -6.06 1.7 3.4

04 -5.18 -4.12 1.4 2.8

05 0 -4 1.5 3


01 -0.72 -4 1 2

02 -3.67 -3.84 0.8 1.6

03 -1.17 -5.10 0.9 1.8

04 -2.14 -5.82 1.6 3.2

05 0 -3 1 2

Page 23

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5


Spir

alit

y (%

)



01 -2.18 -4.73 0.5 1

02 0 -4.95 1.1 2.20

03 -4.83 -3.84 0.7 1.4

04 -1.17 -3.84 0.5 0.72

05 -0.72 -6.79 0.5 0.75


01 -4.37 -4 1 1.45

02 -4.34 -4.9 0.5 0.72

03 -2.17 -4.95 1.2 1.73

04 -4.34 -3.84 1 1.47

05 -4.83 -1.94 0.5 0.72

Fig: Relation between GSM & Spirality% (Hang Dry)

Page 24

-7

-6

-5

-4

-3

-2

-1

0


h

r

i

n

k

a

g

e(

%)

i

n

L

e

n

g

t

h

w

i

s

e


-8

-7

-6

-5

-4

-3

-2

-1

0

120 GSM 130GSM 140 GSM 160 GSM 180GSM

s

h

r

i

n

k

a

g

e(

%)

i

n

W

i

d

t

h

w

i

s

esingle jersey fabric GSM(Cotton)

Fig: Relation between GSM & Shrinkage% (Hang Dry)

Page 25

Flat dry



Twisting

maximum

(cm)

Spirality


01 -3.62 -1.96 1.5 3

02 -4 -4.9 1.9 3.8

03 -3.43 -6.06 1.7 3.4

04 -5.18 -4.12 1.4 2.8

05 0 -4 1.5 3


01 -0.72 -4 1 2

02 -3.67 -3.84 0.8 1.6

03 -1.17 -5.10 0.9 1.8

04 -2.14 -5.82 1.6 3.2

05 -4.83 -3.84 0.7 1.4


01 -2.18 -4.73 0.5 1

02 0 -4.95 1.1 2.20

03 -4.83 -3.84 0.7 1.4

04 -1.17 -3.84 0.5 0.72

05 -0.72 -6.79 0.5 0.75

Page 26

0

0.5

1

1.5

2

2.5

3

3.5

4


Spir

alit

y (%

)



01 -4.37 -4 1 1.45

02 -4.34 -4.9 0.5 0.72

03 -2.17 -4.95 1.2 1.73

04 -4.34 -3.84 1 1.47

05 -4.83 -1.94 0.5 0.72


01 -4.34 -4.9 0.5 0.72

02 -0.72 -6.79 0.5 0.75

03 -4.83 -3.84 0.7 1.4

04 -2.17 -4.95 1.2 1.73

05 -4.37 -4 1 1.45

Fig: Relation between GSM & Spirality% (Flat dry)

Page 27

-6

-5

-4

-3

-2

-1

0


h

r

i

n

k

a

g

e

%

i

n

L

e

n

g

t

h

w

i

s

e

single jersey fabric GSM (Cotton)

-6

-5

-4

-3

-2

-1

0


h

r

i

n

k

a

g

e

%

i

n

W

i

d

t

h

w

i

s

e

single jersey farbic GSM (Cotton)

Fig: Relation between GSM & Shrinkage% (Flat dry)

Page 28

Tumble dry

Single Jersey 120 GSM (Yarn type: Polyester)

Shrinkage Tw spirality

Length

wise

Width

wise

01 +1 +2 1 2

02 0 +1 1.1 2.2

03 -1 -2 1.4 2.8

04 +0.75 +1 1.6 3.2

05 +2 +1 1.2 2.4

Hang dry



Length

wise

Width

wise

01 +0.75 +1 1 2

Page 29

02 0 +1 0.75 1.5

03 -1 -2 1.07 2.1

04 +0.75 +1 0.9 1.9

05 +1 +2 1.08 2.3

Flat dry



Length

wise

Width

wise

01 +1 +2 0.9 1.8

02 0 +1 0.5 1

03 -1 -2 1.05 2.1

04 +0.75 +1 0.75 1.5

05 +2 +1 0.6 1.2

Page 30

0

0.5

1

1.5

2

2.5

3

3.5

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

Spir

alit

y (%

)

Single Jersey Fabric GSM (polyester)

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

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

s

h

r

i

n

k

a

g

e

%

i

n

L

e

n

g

t

h

w

i

s

e

single jersey fabric GSM (Polyester)

Fig: Relation between GSM & Spirality% for polyester yarn in different dry

conditions.

Page 31

Tumble dry

PK 220 GSM (Yarn type: Cotton)


Length

wise

Width

wise

01 -4.37 -4 1 1.45

02 -4.34 -4.9 0.5 0.72

03 -2.17 -4.95 1.2 1.73

04 -4.34 -3.84 1 1.47

05 -4.83 -1.94 0.5 0.72

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

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

s

h

r

i

n

k

a

g

e

%

i

n

W

i

d

t

h

w

i

s

e

single jersey fabric GSM (Polyester)

Fig: Relation between GSM & Shrinkage% for polyester yarn

in different dry conditions.

Page 32

1*1 Rib 220 GSM (Yarn

Type: Cotton)

1 -3.64 +1.04 0.5 0.72

02 -4.85 -3.49 0.5 0.76

03 0 -3 0.5 0.72

04 -2.89 -5.05 0.65 1.3

05 0 -4 0.5 0.74

Interlock 220 GSM (Yarn Type: Cotton)

01 -3.93 0 0.6 1.2

02 -2.17 -1.9 0.5 0.75

03 -1.15 -2.91 0.5 0.75

04 -1.48 -2.04 0.5 0.72

05 -4.34 -2.02 0.5 0.72

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

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

Spir

alit

y (%

)

Fig: Relation between GSM & Spirality% of different types of fabrics

(Tumble Dry)

Page 33

-6

-5

-4

-3

-2

-1

0

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

h

r

i

n

k

a

g

e

%

i

n

L

e

n

g

t

h

w

i

s

e

-6

-5

-4

-3

-2

-1

0

1

2

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

s

h

r

i

n

k

a

g

e

%

i

n

W

i

d

t

h

w

i

s

e

Fig: Relation between GSM & Shrinkage% of

different types of fabrics (Tumble Dry)

Page 34

Tumble dry

Terry Fleece 300 GSM (Yarn type: Cotton)


Length

wise

Width

wise

01 -0.74 -1.05 0.5 0.75

02 -3.49 -3.03 1.8 2.58

03 -2.85 -2.04 1.5 2.9

04 -5.07 -1.01 1 2

05 -1.44 -0.97 1 1.44

Fleece 300 GSM (Yarn

Type: Cotton)

01 -2.72 +1.03 1 1.48

02 -7.64 -3.55 0.5 0.72

03 -4.41 -2 0.7 1.02

04 -1.47 -2.06 2 2.94

05 -4.34 -1 1.5 2.17

Page 35

0

0.5

1

1.5

2

2.5

3

3.5

Terry Fleece (300 GSM) Fleece(300 GSM)

Spir

alit

y (%

)

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

Terry Fleece(300GSM) Fleece(300GSM)s

h

r

i

n

k

a

g

e

%

i

n

L

e

n

g

t

h

w

i

s

e

Fig: Relation between GSM & Spirality% of different

fabrics (Tumble Dry)

Page 36

-4

-3

-2

-1

0

1

2

Terry Fleece(300GSM) Fleece(300GSM)

s

h

r

i

n

k

a

g

e

%

i

n

w

i

d

t

h

w

i

s

e

Fig: Relation between GSM & Shrinkage% of different fabrics

(Tumble Dry)

Page 37

Control of spirality and shrinkage in finishing section

In finishing section fabric GSM, Spirality and shrinkage being controlled in various

finishing machine such as squeezer, dryer, open & tube compactor and stenter.

Some descriptions are given below:

Squeezer:

Textile materials such as knitted fabrics are usually extended in length wise direction due

to tension specially in dyeing process. When the dyed fabrics are passed through the

squeezer dia of the fabric can be controlled by adjusting the width of the spreader frame

by controlling width wise shrinkage. Squeezer machine helps to remove water from the

fabric.

Specification:

Name: squeezer machine.

Brand: SANTAX

Origin: Switzerland.

Data: Squeezer

Fabric

type

Color GSM Machine

speed

Over feed Dia Dia+

Single

jersey

Navy 180 20 +30% 60 +4

Single

jersey

Dark red 160 20 25% 60 +4

Single

Lacoste

Sky blue 150 20 20% 69 +4

Double

lacoste

Avg(wood) 180 20 25% 66 +4

Interlock black 210 20 18% 108 +5

Flat back

rib

black 340 20 15% 75 +5

Page 38

Dryer:

Some water droplet trapped within the fibers and yarns by hydrogen bond are not

removable by squeezing, so to remove these water, the material must be dried. When the

squeezed fabric is passed through the dryer air passing through top and bottom side to the

fabric and makes a wavy shape which helps to keep fabric in relax form and control

length wise shrinkage due to overfeeding which depends on the amount of shrinkage and

expected GSM of the finished fabric.

Specification:

Name: Dryer machine

Brnad: SANTAX

Origin: Switzerland

Data: Drying

Fabric

type

Color GSM Line

speed

Over feed temperature Vibration

Single

jersey

Navy 180 7.1 25% 110/120/130 600

Single

jersey

Dark red 160 7.1 25% 110/120/130 600

Single

Lacoste

Sky blue 150 10 25% 147/150/153 600

Double

lacoste

Avg(wood) 180 7 25% 100/120/130 600

Interlock black 210 6.7 30% 148/150/153 640

Flat back

rib

black 340 8.1 20% 155/160/165 650

Compactor:

Compactor is the most is the most important machine in the finishing section. It helps to

controls fabric width, GSM of the fabric and shrinkage.

Data: compactor

Fabric

type

Color GSM Line

speed

Compaction% dia

Page 39

Single

jersey

Navy 180 40 8% +4

Single

jersey

Dark red 160 40 6% +3

Single

Lacoste

Sky blue 150 25 8% +3

Double

lacoste

Avg(wood) 180 40 18% +5

Interlock black 210 40 15% +8

Flat back

rib

black 340 40 15% +2

In compactor, pre shrinkage treatment is done here. Finally GSM and width are

controlled in this section.

Shoe: electric heating system

Temperature: 98-1050C

Gulling shoe button: used to move the shoe upward and downward.

Feed and retard roller:

heat is given by steam, temperature for both rollers: 60-800C(set: 60-75

0C)

retard roll speed is less than feed roll during compacting.

Shape is used for adjusting the fabric dia before compacting.

The sizes of shape are:

Size 1: 80-120cm

Size 2: 60-92cm

Size 3: 52-70cm

Size 4: 38-50cm

GSM and shrinkage control mechanism:

Page 40

Dia mark is adjusted manually by feeding the fabric through the middle of feed pulley of

the sap. Before compacting the fabric, it is damped by spraying the steam from the steam

box. As the feed roller speed is greater than the retard roll, the fabric is shrunk in length

wise. The blade and the heated shoe are used to give the calendaring effect. The distance

between the blade and the heated shoe is very important for compacting. The closer the

distance, higher the compaction percentage. The sap controls finished dia of the fabric. If

length wise shrinkage is more than required, the fabric is wetted again and dried. Dried

fabric is again compacted by extending the width of the fabric by sap.

Retard roller speed is always slower than feed roll. The speed for the retard roll is

expressed as negative value. It varies according to the design and structure of the fabric.

As for an example:

Types of fabric Retard roll over speed

Single jersey -(6-12)%

Interlock and rib -(10-25)%

Single jersey fleece -(20-30)%

Single and double lacoste, pique -(15-25)%

Lycra single jersey -(30-35)%

Stenter:

In Stenter machines some chemicals i.e. softener, starch are used in fabric for smoothness

of fabric and other properties.

Fabric GSM, shrinkage, width also controlled.

Specification:

Name: Stenter machine

Mahine bran d: FABCON

Origin: USA

Data: Stenter

Fabric

type

Color GSM Required

dia

Finished

dia

Finished

GSM

Shrinkage

in length

wise

Shrinkage

in width

wise

Single Navy 180 60 61 178 -5% -4%

Page 41

jersey

Single

jersey

Dark red 160 60 61 155 -4% -2%

Single

Lacoste

Sky blue 150 69 68 147 -3% -7%

Double

lacoste

Avg(wood) 180 66 63 165 -7% -9%

Interlock black 210 108 109 210 -2% -4%

Flat back

rib

black 340 75 75 345 -4% -3%

Here we see that length wise shrinkage is more than that for width wise shrinkage. Width

wise shrinkage is negative i.e. width of fabric increased. During the dyeing period, fabric

extends length wise in highest possible maximum range. The main reason for this

extension is its behavior. Normally higher the GSM, lower the shrinkage, it is not true

during processing because generally fabric width less than required width, so we can say

that fabric GSM increases and decreases with fabric with decreases and increases in

processing.

Loop dimension changes at different stages:

1) After scouring, bleaching and dyeing:

Loops are extended in lengthwise because of continuous tensioning on the fabric.

Thus the fabric is elongated length wise but shrunk in widthwise.

2) After dewatering and squeezing:

The loops are smaller than the previous one. It is controlled by the overfeeding of

Albatross lower roll (the lower roll is faster than upper roll)

3) After compacting or stentering:

Loops are of perfect size because finished fabric width is controlled accurately.

Besides this, the fabric is compacted length wise considering the standard

shrinkage allowance.

Page 42

Page 43

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.

Page 44

Bibliography:

1) Principle of textile testing;

-J.E. Booth (Third Edition)

2) Watsons textile design and color

-Z. Grosicki (7th

Edition)

3) www.indiantextilejournal.com

4) www.emeraldinsight.com

5) www.encyclopedia.com

6) www.fibre2fashion.com

http://www.indiantextilejournal.com/

http://www.emeraldinsight.com/

http://www.encyclopedia.com/

http://www.fibre2fashion.com/

Documents

Arif 1(Spirility)