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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
Fig: Washing at 800C
Fig: Washing at 900C
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
Single Jersey 130 GSM (Yarn Type: Cotton)
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
Single Jersey 140 GSM (Yarn Type: Cotton)
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)
Single Jersey 160 GSM (Yarn Type: 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
Single Jersey 180 GSM (Yarn Type: Cotton)
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
120 GSM 130GSM 140 GSM 160 GSM 180GSMs
h
r
i
n
k
a
g
e(
%)i
n
W
i
d
t
h
w
i
s
e
single jersey fabric GSM(Cotton)
Fig: Relation between GSM & Shrinkage% (Tumble Dry)
Page 22
Hang dry
Single Jersey 120GSM (Yarn Type: Cotton)
Sample No. Shrinkage
Twisting
maximum
(cm)
Spirality
Length wise Width wise
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
Single Jersey 130GSM (Yarn Type: Cotton)
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
Single Jersey 140 GSM (Yarn Type: 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
Page 23
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
120 GSM 130 GSM 140 GSM 160 GSM 180 GSM
Spir
alit
y (%
)
Single Jersey Fabric GSM (Cotton)
Single Jersey 160 GSM (Yarn Type: Cotton)
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
Single Jersey 180 GSM (Yarn Type: Cotton)
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
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
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
Single Jersey 120GSM (Yarn Type: Cotton)
Sample No. Shrinkage
Twisting
maximum
(cm)
Spirality
Length wise Width wise
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
Single Jersey 130GSM (Yarn Type: 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 -4.83 -3.84 0.7 1.4
Single Jersey 140 GSM (Yarn Type: Cotton)
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
120 GSM 130 GSM 140 GSM 160 GSM 180 GSM
Spir
alit
y (%
)
Single Jersey Fabric GSM (Cotton)
Single Jersey 160 GSM (Yarn Type: Cotton)
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
Single Jersey 180 GSM (Yarn Type: Cotton)
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
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)
-6
-5
-4
-3
-2
-1
0
120 GSM 130GSM 140 GSM 160 GSM 180GSMs
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
Single Jersey 120 GSM (Yarn type: Polyester)
Shrinkage Tw spirality
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
Single Jersey 120 GSM (Yarn type: Polyester)
Shrinkage Tw spirality
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)
Shrinkage Tw spirality
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)
Shrinkage Tw spirality
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