CHAPTER – 4 EFFECT OF PICK SPACING USING ...shodhganga.inflibnet.ac.in/bitstream/10603/25486/13/13...Studies In Mercerization 117 CHAPTER – 4 EFFECT OF PICK SPACING USING COMPACT

Studies In Mercerization

117

CHAPTER – 4

EFFECT OF PICK SPACING USING COMPACT YARN

IN WEFTWAY ON THE PHYSICAL PROPERTIES OF

FABRIC SUBJECTED TO HOT MERCERIZATION

PROCESS.

4.1 Introduction:

The fabric properties are also influenced by the fabric geometry and the

structure of the yarn used [10, 146-148, 158]. Research on compact yarn [148] has

shown better tenacity, elongation and reduced hairiness compared to ring yarns.

In the present research work, an attempt has been made to find out the extent

of changes brought about in fabric properties after hot mercerization using compact

yarn in weft direction only. Similarly, effect of pick spacing on fabric properties is

also studied.

4.2 Materials & Methods:

4.2.1 Materials:-

Woven cotton fabric samples were prepared with following specifications.

Warp Count - 40s (Ring Yarn)

Weft Count - 40s (Compact Yarn)

Ends per Cm - 42

Picks per Cm - 28, 32 and 36

Weave - Plain

The fabric was woven on Airjet Weaving Machine having 323 cm cloth width.


118

4.2.2 Chemicals and auxiliaries:-

The following chemicales were used.

Dilute Bactesol PHC (enzyme),

Sanelozin MRN (Wetting Agent),

Sirix ZUDI (Chelating Agent),

Complex former (Chelating agent),

Wetting agent and Peroxide Stabilizer.

The following auxiliaries were used.

Acetic Acid, Hydrogen Peroxide (50%), Sodium Hydroxide,

Commercial products: Amylase-Enzyme

4.2.3 Methods:-

4.2.3.1 Processing Sequence:

4.2.3.2 Singeing and Desizing:

Grey fabric was singed and desized on Osthoff Senze, Germany, machine at a

speed of 80 meters per minute with 16 cm flame intensity. Desizing was carried out

using 5 grams per litre enzyme, 3 grams per litre wetting agent and 1 gram per litre

Chelating agent at 600C for 6 hours followed by hot wash at 70

0C and cold wash.

Singeing Desizing Hot wash

Combined

Scouring &

Bleaching

Cold wash

Hot wash

Cold wash Hot Wash Acid

Neutralization

Cold wash

Hot

Mercerization


119

4.2.3.3 Scouring and Bleaching:

Desized fabric was padded through

Hydrogen Peroxide (50%) - 35 ml / kg of fabric

Sodium Hydroxide - 25 ml / kg of fabric

Complex former (Chelating agent) - 2.5 ml / kg of fabric

Wetting agent - 4 ml / kg of fabric

Peroxide Stabilizer - 7 ml / kg of fabric

The impregnated fabric was then steamed at 980C for 25 minutes in Benninger

machine followed by hot wash and cold wash.

4.2.3.4 Mercerization:

Mercerization was carried on Benninger AGCH 9240, a chain mercerizing

machine at 25% NaOH concentration with dwell period of 55 seconds at 600C.

4.3 Physical Testing of Fabric:

The samples were conditioned at 270C & 65% R.H. for 48 hours and then

tested for following parameters.

Tearing test:

Tearing test was performed on Elmatear Tearing Strength Tester using ASTM

D1424-96 ISO 9290-1990 method. Sample size was 100 mm x 75 mm. The

instrument holds the specimen in two clamps, one is stationary another one is

moveable. It tears the sample by fall of the pendulum due to the force of gravity. Ten

samples are prepared separately, warp and weft direction, as per the size of template.

The scale shows directly tear strength in grams. The critical distance of 43mm should

be torn during the test. Check the zero position and select the capacity of the machine

so that specimen tears between 20 to 60 percent of the scale value. Release the


120

pendulum by pressing the latch so that specimen will be torn. Hold the pendulum in

its return journey. Read the scale value in grams.

(All other Testing details are as per chapter 3-Physical Testing of fabric)

4.4 Results and Discussion:

4.4.1 Tensile Strength

Comparison of Tensile

Unmercerized Fabric

Hot Mercerized Fabric

% increase in Tensile

strength after Hot

Mercerization

Graph 4.1- Comparison of Tensile strength in

52

54

56

58

60

62

64

66

68

70

Tensile strength

in ( kgf) of Fabric

having 28 Picks

per cm


Results and Discussion:

Tensile Strength:

Table – 4.1

Tensile strength in (kgf) of Unmercerized & Hot

Fabrics (warpway)

Tensile strength in

( kgf) of Fabric

having 28

Picks per cm

Tensile strength in

( kgf) of Fabric

having 32

Picks per cm

Tensile strength in

58.64 61.69

65.36 65.60

11.45 % 6.33 %

Comparison of Tensile strength in (kgf) of Unmercerized & Hot

Mercerized Fabrics (warpway)

Tensile strength

in( kgf) of Fabric

having 32Picks

per cm

Tensile strength

in( kgf) of Fabric

having 36 Picks

per cm

Unmercerized Fabric



121

Hot Mercerized

Tensile strength in

( kgf) of Fabric

having 36

Picks per cm

64.74

68.80

6.27%

Unmercerized & Hot

Unmercerized Fabric



122

Tensile Strength (warpway)

Table- 4.1 and Graph- 4.1 show tensile strength of Unmercerized and Hot

Mercerized fabrics, having 42 warp ends per cm and 28, 32 & 36 picks per cm. 40S

cotton ring yarn is used in warp and 40S cotton compact yarn is used in weft.

It can be seen from the table that as the picks per cm are increased from 28 to

32 & 36, the warpway tensile strength obtained of fabric before mercerization is 58.64

Kgf, 61.69 Kgf and 64.74 Kgf, respectively. After mercerization the tensile strength is

found to be 65.36 Kgf, 65.60 Kgf and 68.80 Kgf for 28, 32 & 36 picks/cm,

respectively. These samples after hot mercerization have shown increase in tensile

strength by 11.45%, 6.33% and 6.27% for 28, 32 & 36 picks/cm, respectively.

It can also be seen that similar to hot mercerized fabric sample having 28

picks/cm, the hot mercerized fabric sample having 32 picks /cm, and the hot

mercerized fabric sample having 36 picks/cm also show increase in tensile strength of

fabric. However, the increase in tensile strength is 0.36% for the fabrics having 32

picks /cm and 5.26% for the fabrics having 36 picks / cm respectively. Thus, change

in pick spacing from 0.9071 mm to 0.7937 mm and 0.7055 mm does not contribute to

significant increase in warpway strength of hot mercerized fabrics.

Tensile Strength (weftway

Comparison of Tensile strength in

Unmercerized Fabric



strength after Hot

Mercerization

Graph 4.2- Comparison of

0

10

20

30

40

50

60

Tensile strength

in ( kgf) of Fabric

having 28 Picks

per cm


way):

Table – 4.2

Comparison of Tensile strength in (kgf) of Unmercerized & Hot Mercerized

Fabrics (weftway)

Tensile strength in

( kgf) of Fabric

having 28

Picks per cm

Tensile strength in

( kgf) of Fabric

having 32

Picks per cm

Tensile strength in

41.75 50.77

45.17 53.24


strength after Hot

8.19% 4.86 %

Comparison of Tensile strength in (kgf) of Unmercerized & Hot

Mercerized Fabrics (weftway)

Tensile strength

in ( kgf) of Fabric

having 32 Picks

per cm

Tensile strength

in ( kgf) of Fabric

having 36 Picks

per cm

Unmercerized Fabric



123

Unmercerized & Hot Mercerized

Tensile strength in

( kgf) of Fabric

having 36

Picks per cm

55.05

56.53

2.68 %

Unmercerized & Hot

Unmercerized Fabric



124

Tensile Strength (weftway):

Table- 4.2 and Graph- 4.2 show tensile strength of unmercerized and hot

mercerized fabric samples having 42 warp ends per cm and 28, 32 & 36 picks per

cm, 40S cotton ring yarn is used warp and 40

S cotton compact yarn is used in weft.

It can be seen from the table that as the picks per cm are increased from 28 to

32 & 36, the weftway tensile strength of fabric before mercerization is 41.75 Kgf,

50.77 Kgf and 55.05 Kgf, respectively. After mercerization the tensile strength is


respectively. These samples after hot mercerization have shown increase in tensile

strength by 8.19%, 4.86% and 2.68 % for 28, 32 & 36 picks/cm, respectively. It can

be observed from Table- 4.2 that the tensile strength increases significantly weft way

as picks per unit space increase from 28 to 32 and 36 per cm before and after hot

mercerization.

However, it can be seen that the relative improvement in tensile strength of

mercerized fabric samples with respect to increase in picks / unit space is not

proportionate. As cover factor increases from 11.23, 12.84 to 14.44 the significant

increase is observed up to cover factor of 12.84 and below. This can be considered as

a limiting factor.

4.4.2 -Tearing strength

Comparison of Tearing strength in( kgf) of Unmercerized and Hot Mercerized

fabrics (wa

Unmercerized Fabric


% increase in Tearing

strength after Hot

Mercerization


1.45

1.5

1.55

1.6

1.65

1.7

1.75

1.8

1.85

1.9

1.95

2

Tearing strength

in kgf of Fabric

having 28 Picks

per cm


Tearing strength:

Table – 4.3


fabrics (warpway)

Tearing strength in

kgf of Fabric

having 28

Picks per cm

Tearing strength

in kgf of Fabric

having 32

Picks per cm

Tearing strength in

1.901 1.799

1.961 1.843


strength after Hot

3.15 % 2.44 %

Comparison of Tearing strength (kgf) of Unmercerized & Hot

Mercerized Fabrics (warpway)

Tearing strength Tearing strength

in kgf of Fabric

having 32 Picks

per cm

Tearing strength

in kgf of Fabric

having 36 Picks

per cm

Unmercerized Fabric



125


Tearing strength in

kgf of Fabric

having 36

Picks per cm

1.635

1.667

1.95 %

Unmercerized & Hot

Unmercerized Fabric


Comparison of Tearing strength (kgf ) of Unmercerized

Unmercerized Fabric



strength after Hot

Mercerization


1.4

1.45

1.5

1.55

1.6

1.65

1.7

1.75

1.8

Tearing strength

in kgf of Fabric

having 28 Picks

per cm


Table – 4.4

Comparison of Tearing strength (kgf ) of Unmercerized and Hot Mercerized

fabrics (weftway)

Tearing strength

in kgf of Fabric

having 28

Picks per cm

Tearing strength in

kgf of Fabric

having 32

Picks per cm

Tearing strength in

kgf of

Picks per cm

1.667 1.646

Mercerized Fabric 1.791 1.722


strength after Hot

7.43 % 4.61 %

Comparison of Tearing strength (kgf) of Unmercerized & Hot

Mercerized Fabrics (weftway)

Tearing strength

in kgf of Fabric

having 28 Picks

Tearing strength

in kgf of Fabric

having 32 Picks

per cm

Tearing strength

in kgf of Fabric

having 36 Picks

per cm

Unmercerized Fabric



126

and Hot Mercerized

Tearing strength in

kgf of Fabric

having 36

Picks per cm

1.536

1.606

4.55 %

Unmercerized & Hot

Unmercerized Fabric



127

Tearing strength (warp & weft):

Table -4.3, Table- 4.4, Graph- 4.3, and Graph -4.4 show tearing strength of

unmercerized and Hot Mercerized fabric samples.

It can observed from the table 4.3 that as the picks per cm are increased from

28 to 32 & 36, the warpway tearing strength of fabric before mercerization is 1.901

Kgf, 1.799 Kgf and 1.635 Kgf, respectively. After mercerization the tearing strength

is found to be 1.961 Kgf, 1.843 Kgf and 1.667 Kgf for 28, 32 & 36 picks/cm,

respectively. These samples after hot mercerization have shown increase in tearing


be observed from Table- 4.4 that the tearing strength decreases as picks per unit space

increase from 28 to 32 and 36 per cm before and after hot mercerization

It can be seen from the table 4.4 that as the picks per cm are increased from 28

to 32 & 36, the weftway tearing strength of fabric before mercerization is 1.667 Kgf,

1.646 Kgf and 1.536 Kgf, respectively. After mercerization the tearing strength is


respectively. These samples after hot mercerization have shown increase in tearing


be observed from Table- 4.4 that the tearing strength decreases as picks per unit space

increase from 28 to 32 and 36 per cm before and after hot mercerization.

The data shows that as pick density increases, tearing strength of fabric in

warp direction significantly reduces before and after mercerization. As pick spacing is

reduced in weft direction by increasing picks per unit space, weft yarns do not help in

strength improvement in warp direction due to increase in binding points. On the

contrary the grouping of threads is prevented and therefore contribution of individual

thread strength in a group is reduced, resulting in decrease in the strength of fabric.

After mercerizing warp way strength does not increases significantly. This reveals

that optimum distance exist between the threads in the fabric for significant

improvement in the tearing strength. The cover factor of fabric assumes great

importance. At the cover factor of 12.63 the tearing strength assumes stable value and

then it does increase significantly as cover factor increases, with reference to the

conditions and samples used in the experimentation.

4.3 Abrasion Resistance

Comparison of Abrasion Resistance in terms of (% loss in weight) for

Unmercerized and Hot

Abrasion Resistance

(% loss in weight) for

Unmercerized Fabric


Graph 4.5– Comparison of Abrasion Resistance

weight) for

1.19%

1.20%

1.21%

1.22%

1.23%

1.24%

1.25%

1.26%

1.27%

1.28%

1.29%

Abrasion

Resistance (%

loss in weight)

for Fabric having

28 Picks per cm


Resistance:

Table – 4.5


Unmercerized and Hot Mercerized Fabric

Abrasion Resistance

(% loss in weight) for

Fabric having 28

Picks per cm

Abrasion Resistance

(% loss in weight)

for Fabric having 32

Picks per cm

1.282 % 1.265 %

1.239 % 1.234 %

Comparison of Abrasion Resistance in terms of

for Unmercerized and Hot Mercerized Fabric

Resistance (%

loss in weight)

for Fabric having

28 Picks per cm

Abrasion

Resistance (%

loss in weight)

for Fabric having

32 Picks per cm

Abrasion

Resistance (%

loss in weight)

for Fabric having

36 Picks per cm


128


Abrasion Resistance

(% loss in weight)


Picks per cm

1.248 %

1.224 %

in terms of (% loss in


Unmercerized Fabric


Comparison of Abrasion


Abrasion Resistance

Thickness) for Fabric

Picks per cm

Unmercerized

Fabric

Hot Mercerized

Fabric


for Unmercerized and Hot Mercerized Fabric.

0.00%

1.00%

2.00%

3.00%

4.00%

5.00%

6.00%

7.00%

Abrasion

Resistance ( %

loss in Thickness)

for Fabric having

28 Picks per cm


Table – 4.6

Comparison of Abrasion Resistance in terms of (% loss in Thickness) for


Abrasion Resistance

( % loss in

Thickness) for Fabric

having 28

Picks per cm

Abrasion Resistance

( % loss in

Thickness) for

Fabric having 32

Picks per cm

( % loss in Thickness)


6.104% 5.590 %

4.056 % 3.539 %

Comparison of Abrasion Resistance in terms of (% loss in Thickness)

Unmercerized and Hot Mercerized Fabric.

Resistance ( %

loss in Thickness)

for Fabric having

28 Picks per cm

Abrasion

Resistance ( %

loss in Thickness)

for Fabric having

32 Picks per cm

Abrasion

Resistance ( %

loss in Thickness)

for Fabric having

36 Picks per cm


129

Resistance in terms of (% loss in Thickness) for

Abrasion

Resistance

( % loss in Thickness)


Picks per cm

4.064 %

2.353 %

(% loss in Thickness)

Unmercerized Fabric



130

4.4.3 Abrasion Resistance:

Abrasion resistance is tested for % loss in thickness and % loss in weight. The

results in Table- 4.5 and Graph- 4.6, Table- 4.6 and Graph 4.6 show % loss in weight

and % loss in thickness of fabric samples. In the warp 40s ring yarn and in the weft

40s compact yarns are used. These fabrics have 42 warp ends per cm and 28, 32 & 36

picks per cm.

It can observed from the Table 4.5 that as the picks per cm are increased from

28 to 32 & 36, the % loss in weight obtained due to abrasion of fabric before

mercerization is 1.282 %, 1.265 % and 1.248 %, respectively. Further after

mercerization the % loss in weight due to abrasion of fabric is found to be 1.239 %,

1.234% and 1.224 % for 28, 32 & 36 picks/cm, respectively. All the samples, after hot

mercerization have shown decrease in % loss in weight due to abrasion of fabric after

mercerization for 28, 32 & 36 picks/cm, respectively. Further it can be observed from

Table- 4.5 that the % loss in weight due to abrasion decreases as picks per unit space

increase from 28 to 32 and 36 per cm for unmercerized as well as hot mercerized

fabric. As the pick density is increased, fabric becomes more compact thereby

offering more resistance to abrasion. Therefore, fabrics having 36 picks per

centimeter show least weight loss while fabrics having 28 picks per centimeter

showed more weight loss. It can also be seen from the Table 4.6 that as the picks per

cm are increased from 28 to 32 & 36, the % loss in thickness observed due to abrasion

of unmercerized fabrics is 6.104 %, 5.590 % and 4.064 %, respectively. For hot

mercerized fabrics the % loss in thickness due to abrasion of fabric is found to be

4.055 %, 3.539% and 2.353 % for 28, 32 & 36 picks/cm, respectively. It can be

observed from Table- 4.6 that the % loss in thickness due to abrasion of fabric

decreases as picks per unit space increase from 28 to 32 and 36 per cm for

unmercerized and hot mercerized fabric samples.


131

As pick density increases the resistance to abrasion is also increases. After hot

mercerization both, % loss in weight and % loss in thickness is reduced for samples

having weft density 28, 32 and 36 per cm respectively. The increased resistance after

mercerization may be due to the removal of convolutions and fibres becoming

cylindrical after mercerization reducing the frictional points.

4.4.4 Drape:

Comparison of Drape Coefficient between

Drape Coefficient

Fabric having 28

Picks per cm

Unmercerized

Fabric

Hot Mercerized

Fabric

Graph 4.7 Comparison of Drape Coefficient between Unmercerized & Hot

0

10

20

30

40

50

60

70

80


Table – 4.7

Comparison of Drape Coefficient between Unmercerized & Hot Mercerized

Fabric samples.

Drape Coefficient of

Fabric having 28

Picks per cm


Fabric having 32

Picks per cm

Drape Coefficient

Fabric having 36

49.64

51.86

74.43 76.08

Comparison of Drape Coefficient between Unmercerized & Hot

Mercerized Fabric.

Drape Coefficient of Fabric

having 28 Picks per cm






132

Unmercerized & Hot Mercerized


Fabric having 36

Picks per cm

56.28

77.41

Comparison of Drape Coefficient between Unmercerized & Hot








133

4.4.4 Drape:

As shown in Table 4.7 and Graph 4.7 the drape coefficient of unmercerized

fabric having 28, 32 & 36 picks per cm was 49.64,51.86 and56.28.The drape

coefficient after hot mercerization increased to 74.43, 76.08 and 77.41. The fabric

becomes stiffer as numbers of picks are increased from 28, 32 & 36 picks per cm. The

effect of increasing stiffness after mercerization may be due to swelling of yarns

thereby reducing the air spaces making denser fabric structure.

4.4.5 Air Permeability:

Comparison of Air Permeability values for Unmercerized & Hot Mercerized

Unmercerized Fabric


% decrease in Air

Permeability

Graph 4.8 – Comparison of Air Permeability

0

5

10

15

20

25

30

35


:

Table – 4.8


fabric

Air Permeability of

fabric having 28

Picks per cm

Air Permeability of

fabric having 32

Picks per cm

Air Permeability of

31.19 24.07

20.62 14.13

33.88 % 41.29 %

Comparison of Air Permeability values for Unmercerized & Hot

Mercerized fabric

Air Permeability of fabric







134


Air Permeability of

fabric having 36

Picks per cm

18.16

9.807

45.99 %

Unmercerized & Hot








135

4.4.5 Air Permeability:

As shown in Table 4.8 and Graph 4.8 the Air Permeability values of the

unmercerized fabrics having 28, 32 & 36 picks per cm was 31.19, 24.07 and 18.16

which after hot mercerization decreased to 20.62, 14.13 and 9.807. Decrease in Air

Permeability for hot mercerized fabrics is found to be 20.62 %, 14.13%, and 9.807%

having picks per centimeter 28, 32 & 36 picks per cm respectively. Decrease in air

permeability could be attributed to increase in the diameter of fibres after

mercerization, thereby making the fabric more compact.

4.5 Conclusions:

1) After the hot mercerization of fabric, using compact yarn in weft

directions, it shows higher tensile strength and drape coefficient as

compare to ring yarn fabric. The abrasion resistance does not change

significantly while air permeability decreases.

2) As picks per cm increases, using compact yarn in weft direction tensile

strength increases, drape coefficient, and abrasion resistance remains

same. Air permeability and tearing strength decrease.

3) The cover factor of 12, assumes optimum performances in tensile strength.

Documents

CHAPTER – 4 EFFECT OF PICK SPACING USING ...shodhganga.inflibnet.ac.in/bitstream/10603/25486/13/13...Studies In Mercerization 117 CHAPTER – 4 EFFECT OF PICK SPACING USING COMPACT