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CHAPTER 3
MATERIALS AND METHODS
3.1 INTRODUCTION
This chapter provides details of cotton fibers, yarns, fabrics used in the
study. The work done in this thesis is presented in the following figure3.1
Figure 3.1
Flow chart for the methodology
The following figure 3.1 gives the overall methodology adopted in the
present study
Physical Properties
Yarn Tenacity
Elongation
Evenness
Hairiness
Imperfections
Tested for tenacity and elongation at gauge lengths of 12.7mm, 25.4mm, 76.2mm, 127.0mm and 254.0mm respectively for Weibull modeling
Conventional yarn50Ne
Compact yarn 50Ne(Suessen Elite)
Cotton Fiber-Type A
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L1 L2 L3 L1 L2 L3 L1 L2 L3
Com Con Com Con Com Con Com Con Com Con Com Con Com Con Com Con Com con
Com-compact, Con-conventional (18 Samples)
Production of weft- knitted fabrics using conventional and compact yarns of 50Ne
Single Jersey Rib Interlock
Scouring
Bleaching
Dyeing
Bio polishing
Wicking-Linear Regression analysis,
Slope,
Intercept
Correlation coefficient,
Spirality
1. Manual method
2. Scanning method
ANOVA &Correlation
coefficient
Total 72 Samples
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Testing of doubled yarn
Conventional yarn50Ne
Compact yarn 50Ne (Suessen Elite)
Doubling
Conventional
+
Conventional
Conventional
+
Compact
Compact
+
Compact
Five Levels of Twist per inch
16.5, 18.0, 20.5, 22, 24
Yarn tenacity, elongation,
hairiness ,imperfections
Analysis of Variance
Cotton Fiber-Type B
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Materials
The materials used in the current research work are discussed below:
3.2 SELECTION OF MATERIAL
The experiments were conducted on two Indian cotton varieties (Mcu5 and
Mcu5). The fiber parameters are measured with HVI. Both were spun to Ne
50(11.8tex). As seen from Table 3.1 the two cottons differ widely in their
characteristics so that they cover a fairly wide spectrum of cottons generally used
for spinning.
The cotton raw material was considered to produce 50s Ne combed
conventional yarn and compact yarn in Suessen Elite Spinning.
Type A cotton yarns have been chosen for knitted fabrics and processing of
them like, scouring, bleaching, dyeing and biopolishing and the fabric properties
have been analyzed. Type B yarns have been doubled (conventional-conventional,
compact-conventional, compact-compact) using TFO machine at five levels of
twist in S direction and their yarn properties were tested and analyzed.
Details of the cotton mixings used for the production of 50s combed yarns
are given in Table 3.1. It may be noted that two different types of cottons were
used for the production of 50s Ne yarns.
Table 3.1
Details of the Cotton Fiber Properties
Fiber parameters Unit Mcu5 Mcu5 2.5%Span Length mm 30.72 30.9
Fiber strength gm/tex 23.08 25.1 Micronaire - 3.7 4.3
Uniformity ratio - 46.89 47
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Methods
3.3 YARN PRODUCTION
3.3.1 Spinning Process parameters for producing Type A yarns
The sequence of process followed for producing 50s combed yarns is given
below.
1. BLOW ROOM
Hcc ventricular speed 1500 rpm
Vario cleaner // Mono speed 650
Grid bar setting 4/6/ 4/6
Hcc ventricular speed 1500 rpm
Vario cleaner // Mono speed 650
Hcc ventricular speed 1500rpm
2. UNIMIX
Unimix beater speed 630
Lattice speed 60mm
Feed roller speed 4.0mm
Feed roller to beat setting 3mm
Grid bar setting 5mm
Waste plate setting 2,2,3,4,4
3. FLEXI CLEANER
Flexi cleaner beater speed- -rpm
425
Feed roller speed 7.0mm
Grid bar setting 5mm
Feed roller to beater 3mm
Waste plate setting 2,2,3,4,4
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4. CARDING
Chute beater speed-rpm 980
Chute wall distance 130mm
Feed plate to licker- in 0.75
Cylinder to flats setting-mm 0.25, 0.25, 0.20, 0.20, 0.20
Cylinder to doffer -mm 0.125
Licker- in speed-rpm 900
Cylinder speed-rpm 500
Flats speed -m/min 13.3 / 24T
Cylinder to SFL C- cleaner 0.375
Cylinder to SFD C- cleaner 0.225
5. LDO/6
Speed hank 0.11
Delivery hank 0.115
Total draft 5.16
Bottom roll setting 40 // 42
Break draft .51
Speed-rpm 350
6. LH-10
No. of ends 20
Break draft 1.43
GMS / MTR 69
Total draft 1.042
Speed-rpm 85
7. COMBER
Table trumpet 4.5mm
Top comb index 1
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Waste% 21%
Deliver hank 0.14
Feed length 4.71
Speed(rpm) 300
8. RSB
Speed-rpm 400
Delivery hank 0.14
Break draft 7.875
Bottom roll setting 39 // 43
Trumpet size 6.2 / 3.5
Scanning roll size 6.4 / 6.7
Scanning roll punnel 6.5mm
Draw off roller 4.8
Web tension tube 7 / 7
Count 50 – BTS2
Speed 950
Break draft 1.095
Total draft 10.02
TPI 1.43 / 1.21
Spacer Green
9. CONDENSOR
Inlet Green
Middle Green
Floating Red
Bottom roll setting 35 / 47 / 48
Top roll setting 37 / 49 / 46
Creel draft 1.034
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10. SPINNING
Total Draft 38.12
Break draft 1.136
Average speed 18.000
Spacer 2.5mm
Traveler 11/OU1UM UDR MAXIMA
3.3.2 Spinning Process for producing Type B yarns
The sequence of process followed for producing 50s combed yarns is given
below.
Process Parameters
1. BLOW ROOM
Lap weight in Kgs 200 gms 22.0
gms / mtr. 336.66
Lap Hank 0.0016
2. SPEED
MFC Speed 440
MPM Speed 720
RK Speed 560
3. SETTING IN MM
Pedal to Beater setting 8.0 mm
Pedal to feed roller 0.125 mm
Beater to stripping plate 1.5 mm
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4. CARDING
Sliver Hank 0.005 0.15
Total Draft 5% 88
Tension Draft 1.71
Waste % 2% 7.0
4.1 Carding Setting
Feed Plate to licker in 1.016
Lickerin to cylinder 0.175
Cylinder to flats 0.20
4.2 Speed in RPM ( 10%)
Licker-in-rpm 960
Cylinder 420
Flat inches/min 7.3
5. DRAWING
Sliver Hank 0.001 0.15
No. of doubling 6
Total Draft 6
Roller setting in mm 38/42
Breaking Draft 1.5
6. COMBER
Total Draft 12.04
Noils 1% 19.0
Type of feed Forward
Feed Length in mm 4.3
Piecing setting +0.2
Draw Box setting in mm 471.56
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7. SIMPLEX
Break Draft 1.21
Total Draft 9.76
Tpi /Tm 1.39/1.2
Spacer size in mm 5.0 mm
Roller Setting in mm 44/50/45 3.3.3 Doubling and twisting of yarn The 50s count yarns both conventional and compact produced from Type B
mixing were doubled in TFO (Two for one twister) employing five levels of twist
(16.5, 18, 20.5, 22.0, 24.0) in S direction. Three levels of doubled yarn were made
with three combinations, conventional and conventional, compact and compact
and conventional and compact (hybrid).This has developed to study the potential
of these yarns.
3.4 YARN TESTING
The skein (lea) count and strength measurements to compute count strength
product were carried out on automated testers. The lea is produced on a wrap reel
by wrapping 120 yards of yarn on a 1.5 yard girth reel. As the yarn counts vary
from the nominal count spun corrections to the CSP were made using the
following formula
Corrected CSP=
countyarn Nominalcountyarn Actual2SPCActual
This measurements of lea strength is a rapid test and is very useful in the
production environment. Both single and doubled yarn were tested for count,
tenacity, elongation, hairiness, imperfections and evenness. The following
Table 3.2 gives details of the Yarn tests
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Table 3.2
Yarn Testing and standards
Nature of the test Instrument Testing Standard
Yarn Count and Count CV% Statex yarn Count system
ASTM D-1907-01
Yarn strength and elongation Ustertensojet Uster standard test method
Yarn evenness, imperfections, hairiness
Uster-5 ASTM D 1425-96
Single yarn strength at different gauge lengths
Instron ASTM D 2256-97
3.4.1 Measurements of yarn count:
Yarn count and count CV% were measured on Statex yarn count system
which is a combination of electronic balance and computer, Using this system,
readings were taken from the yarn samples and the mean value was calculated.
3.4.2 Measurements of yarn Strength and elongation:
All the tensile properties of yarn, (breaking strength and elongation) were
measured on the UsterTensojet using the single strand method .This instrument
works on the CRE principle.
3.4.3 Measurements of yarn hairiness, evenness and imperfections:
The evenness of yarn is one of main indexes to measure the quality of
yarns. The unevenness of yarns will deteriorate the mightiness of yarns, and
increase the end breakage rate in the spinning, and the increase of the end
breakage rate will directly limit the speed of the machines and reduce the
productivity. In addition, the unevenness of yarns will seriously influence the
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appearance quality of textiles. Yarn hairiness and evenness were measured on
Uster Tester 5.
3.4.4 Measurements of single yarn strength at different gauge Length:
The gauge length is the distance between the grips. The conventional and
compact spun yarn having 50’s count and constructed of 100% cotton were tensile
tested using INSTRON tensile tester to determine how their strength varies as a
function of gauge length. Twenty tests were performed at each gauge length of
254.0mm, 127mm, 76.2mm, 25.4mm and 12.7mm.
3.5 FABRIC PRODUCTION
In this work conventional and compact yarns were used to produce Single
jersey, rib and interlock structures with three different loop lengths. The details of
machine type and selection of loop length are given in following
Tables 3.3 to 3.5.
Table – 3.3
Knitting Machinery Details
Particulars Single Jersey Rib Interlock
Machine Falmac Singapore Falmac Singapore Shinta Taiwan
Model FSB 3XSK PN1.6XRB DBR4
Diameter 24 18 20
Gauge 28 18 28
Number of feeders 72 48 40
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Table – 3.4 Loop Length Calculation for the Selected Knit Structures
Knit Structures Samples Tightness Factor Tex0.5cm-1 Loop Length(cm)
Single Jersey R1, C1 14 0.245 R2, C2 15.5 0.221 R3, C3 17 0.206
Rib R4, C4 12 0.286 R5, C5 12.5 0.272 R6, C6 13 0.262
Interlock R7, C7 12 0.286 R8, C8 12.5 0.272 R9, C9 13 0.262
Table – 3.5
Nomenclature of the samples
S.No Samples Yarn Used Knit Structure Loop
Length (in cm)
1 R1 Conventional yarns Single jersey 0.245 2 R2 Conventional yarns Single jersey 0.221 3 R3 Conventional yarns Single jersey 0.206 4 R4 Conventional yarns Rib 0.286 5 R5 Conventional yarns Rib 0.272 6 R6 Conventional yarns Rib 0.262 7 R7 Conventional yarns Interlock 0.286 8 R8 Conventional yarns Interlock 0.272 9 R9 Conventional yarns Interlock 0.262 10 C1 Compact yarns Single jersey 0.245 11 C2 Compact yarns Single jersey 0.221 12 C3 Compact yarns Single jersey 0.206 13 C4 Compact yarns Rib 0.286 14 C5 Compact yarns Rib 0.272 15 C6 Compact yarns Rib 0.262 16 C7 Compact yarns Interlock 0.286 17 C8 Compact yarns Interlock 0.272 18 C9 Compact yarns Interlock 0.262
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3.6 CHEMICAL TREATMENTS
With a view to investigating the effects of chemical treatments on the
properties of knitted fabrics, they were subjected to chemical treatments and these
are described below. Commercially obtained chemicals were used in all treatments
The investigator has subjected the conventional and compact spun knitted
fabrics to scouring, bleaching, dyeing and finishing processes.
The processes were carried out under normal industrial parameters.
3.6.1 Scouring
Scouring is the process in which natural as well as artificial impurities are
removed. The ultimate aim of the scouring is to make the material uniformly and
highly absorbent in a cost-effective manner so that there are no difficulties in the
later processes of dyeing, printing and finishing
The scouring solution contained the following ingredients
Scouring Recipe:
Sodium hydroxide : 3.0 %
Sodium Silicate : 0.1%
Material: Liquor Ratio : 1: 20
Wetting Agent : 0.1%
Reaction Time : 1 Hour
Temperature : Boiling
The weighed amount of sodium hydroxide was wetted with wetting agent
followed by sodium silicate. The calculated amount of water was added to it. The
temperature was raised to 100 ºC and was kept for an hour. Then the fabrics were
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taken out and thoroughly washed followed by flat drying for two days. The fabrics
were then dried in oven for not more than 70 ºC. After 12 hours, the fabrics were
ready for wickability testing.
3.6.2 Bleaching
Bleaching is the process in which we remove the color pigments in order to
achieve the degree of whiteness. The bleaching of textile fibers with hydrogen
peroxide is certainly the most popular process today because it is
1. Environmental friendly. (Potentially it can decompose into oxygen and Water).
2. It is versatile (it can used hot or cold batch wise and continuous)
Bleaching Recipe:
Hydrogen peroxide : 3 %
Sodium Silicate : 3%
Soda Ash : 1 %
Sodium hydroxide : 0.5%
Material: Liquor Ratio : 1: 20
Reaction time : 1 Hour
Temperature : 70 ºC
The weighed amount of hydrogen peroxide, sodium silicate and soda ash
were mixed with the required amount of water and the temperature of the bath was
raised to the boiling point and kept for an hour. Then the samples were taken out
and after thorough washing and drying, they were ready for testing.
3.6.3 Dyeing
The reactive dyes offer a wide range of dyes with varying shades, fastness,
with high brilliancy, easy applicability and reproducibility. In addition to giving
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high wash fastness on cotton, reactive dyes usually give bright shade. Reactive
dyes have moderate to good light fastness and fair- to- poor chlorine fastness.
Hence the reactive dyes for dyeing the bleached knitted fabrics were
selected
Dyeing Recipe:
Machine : Soft Flow Machine
Dye : Reactive Dye (Yellow-0.08Gpl, Red-
0.05Gpl, Blue-0.2Gpl)
Salt : 50gpl (Time- 30 Minutes)
SodaAsh : 10gpl (Time- 45 Minutes)
Material: Liquor Ratio : 1: 20
Temperature : 60 ºC
The dyeing was carried out in industry under normal industrial practices.
3.6.4 Bio Polishing Finish
Biopolishing result in smooth fabrics with enhanced appearance and handle
.As mechanical force is involved in scouring, bleaching, it increases the fuzz on
cottons knit fabrics. The hairiness or fuzz that produced in the last stage can be
reduced when bio polishing is introduced with cellulase enzyme. Acid cellulases
enzyme is concentrated, non-GMO based biopolishing enzyme, can achieve
desired results at lesser dosage and less processing time.
Biopolishing Recipe:
Machine : Winch and Tumble Dryer
Enzymes : Acid cellulases (Ezysoft GM3)
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Material: Liquor Ratio : 1: 15
Reaction time : 1 Hour
Temperature : 55 ºC
The biopolishing requires equipment such as washing machine or winch
machine. The machine was filled with water, material liquor ratio was taken as
1:15, then bio wash liquid and softener was added to the winch. The pH was
maintained between 4.5 and 5.5; the bio wash was carried out for 1 hour. Cold
rinse for 5 – 10 minutes was followed by hydro extraction and tumble dry.
3.7 FULL RELAXATION
In order to achieve the fully relaxed state, all the treated knitted samples
were subjected to static wetting in water containing wetting agent for 24h at room
temperature, followed by gentle agitation in water heated up to 70oC which is
maintained for 30 min (laundering). The sample were then tumble dried at 80o c
for about 1 hr, The cycle of laundering, hydro extraction and tumble drying was
carried out for five times. This method was considered to fully relax the samples
in view of the results of Knapton et al. (1985).The desired fabric parameters were
subsequently measured and recorded after conditioning the samples at 25o
C,65%RH for several days.
3.8 FABRIC TESTING
After full relaxation, the properties of the processed fabrics were analyzed
at standard atmosphere conditions of 65% relative humidity and at 27± 2° C. The
geometrical fabric properties tested were loop length, wales per cm, courses per
cm, area density and thickness. Bursting strength, spirality and wickability were
also tested.
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3.8.1 Measurement of wales per cm
The samples of 10 cm x 10 cm size were marked at ten different places in
the fabric, using the pick glass, the numbers of wales were counted and the result
was divided by 10 to determine the number of wales in 1 cm.
Number of wales in 10 cm. Wales per cm = ----------------------------------- 10
3.8.2 Measurement of Courses per cm
The samples of 10 cm x 10 cm size were marked at ten different places in
the fabric. Using the pick glass, the numbers of courses were counted and the
result was divided by 10 to determine the number of course in 1 cm.
Number of course in 10 cm. Course per cm = ----------------------------------- 10 3.8.3. Stitch density: (ASTM D 3887)
Stitch density is the number of loops per unit area, which can be obtained
by multiplying the number of Wales and courses per unit length;
Stitch density in sq. cm = Wales per cm x Course per cm.
3.8.4 . Measurement of Loop length
The loop length is the length of yarn used in one knitted loop.100 Wales are
counted from each dry relaxed knitting sample. 10 courses were unraveled from
these samples and every course average length was measured using a scale. These
average lengths were divided by 100, which is the total wale number and the loop
length is calculated.
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3.8.5. Measurement of fabric weight (ASTM 3776)
Calculating the mass per unit area and expressing as g/m2 (GSM) is
customary for knitted fabric. A circular specimen of size 100 cm2 was cut rapidly
and accurately by using sample cutter. Sample cutter for GSM is a specialized
instrument to determine the GSM of the fabric.
GSM states the determination of weight per unit area, which is exactly
1/100th of a sq. meter. The results in grams, multiplied by 100 gives the GSM.
GSM = Specimen weight in grams x 100
3.8.6Measurement of Wickability
Sample size
The sample size for wicking measurement was 1" Wide and 10 " long. The
samples were cut in both wales wise and course wise directions in conventional
spun and compact spun scoured, bleached, dyed and finished single jersey, rib and
interlock structures.
Wicking instrument
The wicking instrument was developed which is made of wood. It consists
of two pillars on either side with a flat rod at the top for easy hanging of the
sample and the bottom edge of the sample is faced towards the beakers containing
distilled water, acidic solution and alkaline solution. (Plate I)
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Wicking measurement
The wicking behaviour of all the samples was analyzed by the vertical
wicking strip test. Measurements were taken out by ordinary capillary rise method
on all the samples. On all fabric strips (scoured, bleached, dyed and finished),
three lines after each cm were made to indicate the height of the capillary
ascension. To initiate the test, end of the samples were immersed into the beakers
containing distilled water, acidic solution and alkali solution. Wicking property
was tested according to the rise in the level of the water and other solutions. Lesser
the time taken to climb, better the wicking property of the fabric. Every time the
front liquid reaches a line, time is recorded. The tests were carried out at the same
atmospheric conditions (65 % ± 2 % Relative humidity and 27 ºC ± 2 ºC
Temperature) on all the samples. (Plate II)
3.8.7 Measurement of spirality
Several standards are available for determining the spirality of knitted
fabrics, eg. ASTM D3882-88-1997. British standard 2819 (1990) IWS test method
No. 276, AATCC test method 179-2004.
The spirality was measured according to the IWS 276 standard test method
(Degirmenci and Topalbekiroglu, 2010). According to this method, 5 different
places are chosen for each sample. First a wale is marked by pen, and the course
linked wale is then marked, as seen in Figure 3.2. By using a protractor, the angle
different from the normal of the wale is measured.
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QP B
AA’
180 180
90
3.8.7.1.Determination of angle of wale spirality: Manual method
The following steps were included to determine the spirality
The fabric samples were relaxed at room temperature for 72 hours to test
the spirality. The specimen was spread on a flat surface without any
tension.
Place the protractor along the course line PQ so that the line AB is
perpendicular to PQ.
Determine accurately the path of the wale line A’ that intersects with the
bottom of 90º line on the protractor.
The angle between the 90º line and wale line <ie AA’> is measured and
direction of spirality (right – left) is recorded.
Repeat this process 10 times. Finally the mean is calculated. The
percentage of spirality is calculated with the following equation.
PS% = AB-BA’ =
Where x is the angle of spirality.
Figure 3.2
Measurement of spirality by manual method
100XABx
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3.8.7.2 Determining the spirality by CorelDraw software
Tools used
- Pick Tool
- Pen Tool
- Zoom Tool
- Dimension Tool
The cotton-plain-knitted fabric samples used in this study have been dry
relaxed and prepared as 5”x5” square. Image of the sample have been acquired via
a scanner with 1200 resolution.
Image was opened with corel draw graphics suite 12 version. The following
steps were framed to measure the angle of spirality.
Step: 1
The first step is to magnify the knitted structure to 3-5 times larger using
zoom tool. After magnifying the knitted structure of single jersey fabric with wale
and course is clearly shown.
Step: 2
In the second step the pen tool is selected to draw a horizontal line and then
the angular dimension tool is used to measure the angle of spirality. The
dimension tool is dragged from bottom of the horizontal line to draw a vertical line
upto 2” and then it is dragged towards the direction of wale line that intersects the
course line. The angle is automatically displayed on the screen which periodically
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represents the wale’s angle (Figure 3.3) and it is to be recorded. The percentage of
spirality was calculated with the following equation:
PS% = 90-MV =
Where MV is the mean value
x is the percentage of spirality.
Figure 3.3
Knitted fabric sample showing spirality
10090
Xx
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3.8.8 Measurement of bursting strength (ASTM D 3786)
The bursting strength of the single jersey, rib, and interlock knitted fabrics
was tested with hydraulic bursting strength tester. The fabric specimen was
clamped by a ring over a thin flexible rubber diaphragm which itself was clamped
over a circular hole in the upper face of a reservoir. The pressure in the liquid was
increased by valves and due to increase in pressure the diaphragm bulges and the
fabric bursts and the pressure at that point was indicated by the pressure gauge.
The tests were carried according to ASTM standard. The readings were noted in
kg/cm 2.
3.8.9. Measurement of thickness (ASTM D 1777)
Thickness is the distance between one surface to its opposite in textiles, the
distance between the upper and lower surface of the material, measured under a
specified pressure.
Thickness is one of the basic physical properties of textile materials. Bulk
and warmth properties of textile materials are often estimated from their thickness
values, and thickness is also useful in measuring some performance
characteristics, such as before and after abrasion and shrinkage. The thickness
value of most textile materials will vary considerably depending on the pressure
applied to the specimen at the time the thickness measurement is taken.
MAG Thickness tester was used to measure thickness. The pressure foot
was lifted with the help of the lifting lever fixed on the top of the dial gauge. Then
the specimen was placed on the anvil and the pressure foot was lowered down
gently onto the specimen. Then the readings were noted on the dial gauge to get
the thickness of the specimen. The above procedure was repeated to obtain the
value of thickness and the average thickness was reported.
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3.9 STATISTICAL ANALYSIS
Weibull software was used to obtain the values of shape and scale
parameters for tenacity and elongation at different Gauge length of 12.7mm,
25.4mm, 76.2mm, 127.0mm and 254.0mm.
The doubled yarn with three combinations, (conventional and conventional,
compact and compact and conventional and compact) were analyzed statistically
by Analysis of Variance.
The test results were analyzed statistically, with the view to finding out the
samples having better wicking. Correlation is a statistical device which helps us
in analyzing the association of two or more variables, says Gupta (2008). The
slope is the vertical distance divided by horizontal distance between any two
points on the line, which is the rate of change along the regression line. Intercept
calculates the point at which a line will intersect the y-axis by using existing x-
values and y- values. The standard error is the measure of the amount of error in
the prediction of y for an individual x. Confidence intervals display 95%
confidence intervals for each regression coefficient tests.
Analysis of variance and correlation coefficient were applied to find out
if there is statistically significant difference between conventional and compact
single jersey fabric data obtained from two methods (Manual method and
CorelDraw method) of measuring spirality.
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