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Fabric Technology - Mini Project Report


This mini project was prepared to fulfill requirement of fabric technology subject at the open university of Sri Lanka, Nawala, Nugegoda
Author: K.K.T Madhusanka (My Answer)

Warp count in tex

Description  
In warp count find linear density of warp direction of fabric and warp count commonly calculated in to tex and it means how many grams in 1000 m length of yarn.  

Methodology
-          Firstly 20 cm length of warp direction based five samples were cut diagonally using 20 cm template.
-          Next, one yarn was removed each five samples.
-          Next, each yarn was unprimed using crimp tester individually and uncrimped length was recorded.
-          Then, weights of each uncrimped yarn specimen were recorded individually.
-          Finally all details were distributed and Tex value was calculated.     

Calculation
Sample No:
Length
Uncrimped length

Uncrimped length (m)
Weight
1
20 cm
20.2 cm
0.202 m
0.0069 g
2
20 cm
20.3 cm
0.203 m
0.0066 g
3
20 cm
20.2 cm
0.202 m
0.0055 g
4
20 cm
20.1cm
0.201 m
0.0068 g
5
20 cm
20.1cm
0.201 m
0.0055 g
Average
20.18 cm
0.2018 m
0.00626 g
  






Sample No: 01
In 20.2 cm uncrimped length’s weight = 0.0069 g
For 1000 m  weight  = (0.0069 g/ 20.2 x 10-2m) x 1000 m
                                            = 34.15841584 g
                                            = 34.16 Tex
  
Sample No: 02
In 20.3 cm uncrimped length’s weight = 0.0066 g
For 1000 m weight   = (0.0066 g/ 20.3 x 10-2m) x 1000 m
                                            = 32.51231527g
                                            = 32.50 Tex

Sample No: 03
In 20.2 cm uncrimped length’s weight = 0.0055 g
For 1000 m weight   = (0.0055 g/ 20.2 x 10-2m) x 1000 m
                                            = 27.22772277g
                                            = 27.23 Tex

Sample No: 04
In 20.1 cm uncrimped length’s weight = 0.0068 g
For 1000 m weight   = (0.0068 g/ 20.1 x 10-2m) x 1000 m
                                            = 33.83084577g
                                            = 33.90 Tex

Sample No: 05
In 20.1 cm uncrimped length’s weight = 0.0055 g
For 1000 m weight   = (0.0055 g/ 20.1 x 10-2m) x 1000 m
                                            = 27.36318408g
                                            = 27.40 Tex

Average Tex value =  (34.16 Tex + 32.50 Tex + 27.23 Tex + 33.90 Tex + 27.40 Tex)/5
                                          = 31.038 Tex

Observations

·         When uncrimping yarns small length of yarn was increased.
·         Increased uncrimped length was little bit difference on each five specimen yarn.
·         When weight test of uncrimped yarns individually, small weight difference of each yarn specimen was found.
Conclusion
·         Each place of fabric had small thick and thin places of warp direction shown small warp count in Tex value (little bit) of each test specimen hence, can conclude this fabric has small Tex variation at several places of fabric.
·         Tex variation were little bit amount hence, can be concluded this fabric has good and acceptable warp count in each area and this is good fabric and suitable for clothing manufacturing process.
(ii)
Weft count in tex

Description  
In weft count find linear density of weft direction of fabric and weft count commonly calculated in to tex and it means how many grams in 1000 m length of yarn.  

Methodology
-          Firstly 20 cm length of weft direction based five samples were cut diagonally using 20 cm template.
-          Next, one yarn was removed each five samples.
-          Next, each yarn was unprimed using crimp tester individually and uncrimped length was recorded.
-          Then, weights of each uncrimped yarn specimen were recorded individually.
-          Finally all details were distributed and Tex value was calculated.    

Calculation
Sample No:
Length
Uncrimped length

Uncrimped length (m)
Weight
1
20 cm
20.4 cm
0.205 m
0.0062 g
2
20 cm
20.5 cm
 0.205 m
0.0058 g
3
20 cm
20.4 cm
0.204 m
0.0059 g
4
20 cm
20.2 cm
0.202 m
0.0053 g
5
20 cm
 20.4 cm
0.204 m
0.0054 g
Average
20.38 cm
0.2038 m
0.00572 g
  






Sample No: 01
In 20.4 cm uncrimped length’s weight = 0.0062 g
For 1000 m  weight  = (0.0062 g/ 20.4 x 10-2m) x 1000 m
                                            = 30.39215686 g
                                            = 30.40 Tex
  

Sample No: 02
In 20.5 cm uncrimped length’s weight = 0.0058 g
For 1000 m weight   = (0.0058 g/ 20.5 x 10-2m) x 1000 m
                                            = 28.29268293g
                                            = 28.30 Tex

Sample No: 03
In 20.4 cm uncrimped length’s weight = 0.0059 g
For 1000 m weight   = (0.0059 g/ 20.4 x 10-2m) x 1000 m
                                            = 28.92156863g
                                            = 28.92 Tex

Sample No: 04
In 20.2 cm uncrimped length’s weight = 0.0053 g
For 1000 m weight   = (0.0053 g/ 20.2 x 10-2m) x 1000 m
                                            = 26.23762376g
                                            = 26.24 Tex

Sample No: 05
In 20.4 cm uncrimped length’s weight = 0.0054 g
For 1000 m weight   = (0.0054 g/ 20.4 x 10-2m) x 1000 m
                                            = 26.47058824g
                                            = 26.50 Tex

Average Tex value =  (30.40 Tex + 28.30 Tex + 28.92  Tex + 26.24 Tex + 26.50 Tex)/5
                                          = 28.072 Tex


Observations

·         When uncrimping yarns, small length of yarn was increased.
·         Uncrimp length of weft yarns were bit higher than warp yarns uncrimp lengths. 
·         Increased uncrimped length was little bit difference on each five specimen yarn.
·         When weight test of uncrimped yarns individually, small weight difference of each yarn specimen was found.

Conclusion
·         Weft yarn had higher crimp than warp yarn.
·         Each place of fabric had small thick and thin places of weft direction shown small weft count in Tex value (little bit) of each test specimen hence, can conclude this fabric has small Tex variation at several places of fabric.
·         Tex variation were little bit amount hence, can be concluded this fabric has good and acceptable weft count in each area and this is good fabric and suitable for clothing manufacturing process.

(iii)
Warp density

Description  
In warp density count, find how many ends/ yarns available in one square inch or square centimeter of warp direction of fabric.  

Methodology
-          2 x 2 cm counting glass was kept on fabric.
-          Simple pen marks were kept on each nook inside of counting glass covered fabric area connected them for correct reading
-          Next counting lens was focused with eye and counted number of warp yarns in square area using needle.
-          Finally warp density was converted in to one centimeter and inch (1 inch = 2.54 cm).

Calculation
Sample No
Warp Density in 2 cm
Warp Density in 1 cm
Fixed for 1cm
1
45
22.5
22
2
46
23
23
3
45
22.5
22
4
45
22.5
22
5
46
23
23
Average
45.4
22.7
22

Here final warp density value was selected as averaged values without decimal points hence,
Warp density in 1 square centimeter = 22
Warp density in 1 inch   = 22.7 x 2.54
                                        = 57.658
Hence taken as, less val  = 57

Observations
·             
·         When warp density counting, of five places found different number of yarn values.
·         When averaging such value decimal points were not taken as density count and fix number was taken.  
·         Warp yarn density has high value than weft density
Conclusion
·         Warp beam arranging with weaving preparatory process, some warp yarn had arranged with small gap and sometime when weaving small unbalance had been occurred in some places.
·         Weaving preparatory process, arrange higher number of warp yarns on warp beam to get optimum strength.

(iv)
Weft density

Description  
In weft density count, find how many picks/ yarns available in one square inch or square centimeter of weft direction of fabric.  

Methodology
-          2 x 2 cm counting glass was kept on fabric.
-          Simple pen marks were kept on each nook inside of counting glass covered fabric area connected them for correct reading
-          Next counting lens was focused with eye and counted number of weft yarns in square area using needle.
-          Finally weft density was converted in to one centimeter and inch (1 inch = 2.54 cm).

Calculation

Sample No
Weft Density in 2 cm
Weft Density in 1 cm
Fixed for 1cm
1
43
21.5
21
2
44
22
22
3
42
21
21
4
42
21
21
5
43
21.5
21
Average
42.8
21.4
21.2 (21)

Here final weft density value was selected as averaged values without decimal points hence,
Weft density in 1 square centimeter = 21
Warp density in 1 inch   = 21 x 2.54
                                        = 53.34
Hence taken as, less val  = 53

Observations
·             
·         When weft density counting, of five places found different number of yarn values.
·         When averaging such value decimal points were not taken as density count and fix number was taken.  
Conclusion
·         When weaving process weft yarn goes around warp yarns hence high crimp and little unbalance had been occurred.
·         This fabric’s warp and weft density count different number of yarn value had small gap hence, can be conclude this fabric had good ends per inch and picks per inch value and suitable for clothing manufacturing process.  

 (v) Cloth cover factor

 Description  
In warp density count, find how many ends/ yarns available in one square inch of warp direction of fabric and to find warp cover factor, warp density divided by square root of warp yarn’s cotton count. In weft density count, find how many picks/ yarns available in one square inch of warp direction of fabric. And to find weft cover factor, weft density divided by square root of weft yarn’s cotton count.

              Cloth cover factor = Warp cover factor (k1) + Weft cover factor (k2)

Methodology
-          Firstly, warp density (per cm) was converted in to ends per inch (1 inch = 2.54 cm).
-          Warp count in Tex was converted in to cotton count (Tex x Ne = 590.5).
-          To find warp cover factor (k1) warp density was divided by square root of cotton (Ne) count.
-          Next, weft density (per cm) was converted in to picks per inch (1 inch = 2.54 cm).
-          Weft count in Tex was converted in to cotton count (Tex x Ne = 590.5).
-          To find weft cover factor (k2) weft density was divided by square root of cotton (Ne) count.
-          Finally by adding total value of k1 and k2, cloth cover factor was calculated.
-
Calculation

Warp density               = 57.658 /inch
Ne value of warp         = 590.5/Tex
                                     = 590.5/31.038
                                     = 19.02506 Ne
Warp cover factor (k1) = Warp density/√Ne
                                     = 57.658/√19.02506
                                     = 13.2189

Weft density               = 53.34 /inch
Ne value of weft         = 590.5/Tex
                                     = 590.5/28.072
                                     = 21.0351952 Ne
Weft cover factor (k2) = Weft density/√Ne
                                     = 53.34/√21.0351952
                                     = 12.4280097
                                     = 11.63000

Cloth cover factor = Warp cover factor (k1) + Weft cover factor (k2)
                                = 13.2189 + 11.63000
                                = 25.4976233
                                = 24.849

Observations
·             
·         Cloth cover factor depend on yarn count
·         Cloth cover factor depend on number of yarn in square inch.
·         Warp area found little high cover factor than weft
Conclusion
·         Cloth cover factor is combination of weft and warp cover factor
·         Cloth cover factor depending on warp and weft density
·         Cloth cover factor depending on linear density of weft and warp yarn.

(vi) GSM Test

Description  
G.S.M means grams per square meter and it means areal density of particular fabric. If higher weight available in square meter, considered as higher GSM based fabric and higher area density. If low weight available in square meter, considered as low GSM based fabric and low area density it means light weight fabric.
Methodology
-          Firstly, five samples were cut using 100cm2 area based G.S.M cutter.
-          Next, each specimen weight was measured individually.
-          Finally each sample’s mass divided by area. 
Calculation
 
Sample No
Weight
GSM by multiplying 100
1
1.1562
115.62
2
1.1741
117.41
3
1.1589
115.89
4
1.1511
115.11
5
1.1479
114.79
Average
1.15764
115.764

Here original calculation can be written as for averaged weight,

              =   Grams/ Square meter

Here 1.15764 averaged weight was found in 100 square centimeter hence, need to find real weight for one square meter.
                                  = (1.15764g/100 x 10-4 m2)
                                  = (1.15764g/1x 10-2m2)
 It can be written as,  = (1.15764g x 100 m-2)
                 GSM         =  115.764 gm-2

Observations
·             
·         Little bit different gram values and G.S.M value found in cut samples
·         Near to selvedge place was seen bit high GSM value than middle of fabric area based samples.  
Conclusion
·         Some area of fabric has thick and thin yarn based places change linear density of yarns and grams per square meter (GSM) value.
·         According to tightly parallel yarn packing of nearest area of selvedge have bit higher grams per square meter value than middle of fabric.

(vii) Colour (by visual inspection)

Description  
Colour of fabric is essential part of fabric. Different colours, repeats, designs based of fabrics are used in textile and apparel industry to get consumer attraction. And in laboratory test basically colour check visually as well as using machinery just like L*a*b* values. Apart this, colour fastness properties due to external resources just like light, abrasion, washing, perspiration, etc are considered. Simply colour of fabric can be explained when sun light falling in to fabric, certain amount of wave length of white light is absorbed by fabric and other waves are reflected. This reflected wave complex give sensation to human eye is identified as fabric colour.
   
Methodology & Colour Assessment
-          Several places of plain woven fabric were visually inspected and roughly colour is identified as somewhat light yellow colour.
-          Several places of plain knitted fabric were visually inspected and roughly colour assessed as off white. 
Observations
·             
·         Colour was roughly assessed without using assessing tools and equipment
·         For assessing colour using eye counting glass lens was used to identify dark spots.
Conclusion
·         Dark spots of plain woven grey fabric may size coat particles or foreign materials.
·         Knitted fabric has small colour shade on off white area and concludes as dust or foreign materials on some area of fabric.
·         This is only rough assessment and to get accuracy of colour it is essential to use colour assessing procedure just like L,A,B or other colour evaluation and distribution method. 
     
(viii) Tensile Strength in Warp and Weft Directions

Description  
In tensile test resistance of the particular fabric sample against perpendicular tensile force applied on it, is considered and in this test each five samples of warp and weft specimens are used. In grab method measures effective strength and in strip method strength with parallel yarns is measured.  

Methodology
-          There were five warp and five weft samples cut according to the given template to met length 20 cm.
-          Before cutting warp direction were marked by arrow.
-          Next, both of width sides of cut specimen were fayed 0.5 cm.
-          Next, tensile strength tester was switch on and software was run.
-          Next, testing procedure was selected using software. (Eg: AATCC, ISO, etc.)
-          Next machine settings were applied just like gauge length, load cell, extension mm, etc.
-          After, selected weft or warp option button of software.
-          In after specimen was clamped on machine.
-          Next,  force was adjusted “0”
-          Next, pre pressure added.
-          Then, using test specimen command button of software, test was launched.
-          Finally load elongation curve based results were recorded.

Calculations/ Recordings\

Sample
Warp
Weft
Breaking Force
Elongation
Breaking Force
Elongation
1
235 N
18.75 mm
217.8 N
16.94 mm
2
236 N
17.68 mm
142.1 N
17.26 mm
3
232.3 N
17.6 mm
160.6 N
18.32 mm
4
234.5 N  
17.84 mm
150.6 N
16.72 mm
5
192.6 N
16.36 mm
151.4 N
17.24 mm
Average
226.08 N
17.646 mm
164.5 N
17.296 mm

Observations
·         In warp specimen’s tensile test found higher breaking force ratio to comparison its elongation values.
·         In weft specimen’s tensile test found higher elongation ratio to comparison its breaking force.
·         Warp specimens tensile strength were higher than warp specimens tensile strength.
 ·             
Conclusion
·         Weaving preparatory process in warp beam arrangement use highly twisted, strength and size coated yarns gives higher strength and low elongation of warp direction fabric.
·         Weft warns goes around warp yarns and creates higher crimp hence, when tensile load high crimp try to uncrimp then conclude weft direction has higher elongation ratio by comparison to its tensile strength. 

PART 02: Calculations for Weft Knitted Fabrics

Course per cm

Description  
In this practical test count how many courses available in one centimeter.

Methodology
-          First knitted fabric was spread on table without stretching.
-          Counting glass was kept on knitted fabric.
-          Eye focused on counting glass lens.
-          Counting process was started using sharp pointed needle or rod.
-          This counting process was done widthwise of fabric and repeated on five places.
-          Finally each result was recorded.    

Calculations/ Recordings

Place
No. of course per 2cm
No. of course per 1cm
course per inch
1
35
17.5
44.45
2
35
17.5
44.45
3
35
17.5
44.45
4
35
17.5
44.45
5
35
17.5
44.45
Average
35
17.5/cm
44.45/inch

Here each observation were taken using 2cm x 2cm  hence, finally 17.5 average was found but courses count should not decimal points based hence courses/cm value is concluded as 18.
Observations
·         When counting courses using counting glass constant of results found.
Conclusion
·         Fabric had perpendicular spreading without stretching or crushing when test hence accurate outcomes found.  

(ii) Wales per cm

Description  
In this practical test count how many Wales available in one centimeter.

Methodology
-          First knitted fabric was spread on table without stretching.
-          Counting glass was kept on knitted fabric.
-          Eye focused on counting glass lens.
-          Counting process was started using sharp pointed needle or rod.
-          This counting process was done lengthwise of fabric and repeated on five places.
-          Finally each result was recorded.   

Calculations/ Recordings

Place
No. of Wales per 2cm
No. of Wales per 1cm
Wales per inch
1
28
14
35.56
2
27
13.5
34.29
3
27
13.5
34.29
4
28
14
35.56
5
27
13.5
34.29
Average
27.4
13.7/cm
34.798/inch

Here each observation were taken using 2cm x 2cm  hence, finally 13.7 average was found but wales count should not decimal points based hence wales per cm value is conclude as 14.
Observations
·         When counting wales using counting glass two types of results found. (27 and 28)
Conclusion
·         Some places of knitted fabric may have slightly stretch or pressed hence, conclude outcome may have changed due to that reason. 

(iii) Stitch density

Description  
In this practical test, hope to find how many density of stitches available in one square centimeter.

Methodology
-          Multiplied provisory found courses per centimeter and wales per centimeter.   

Calculations/ Recordings

                    Stitch density (SD) = Course density x Wales density
                                                   = (Course/cm) x (wales/cm)
                                                   = 18cm-1 x 14cm-1
                                                   =  252 cm-2

(iv) Stitch length

Description
Stitch length can be explained as theoretically the single length of yarn which include one
needle loop and half of a sinker loop between that needle loop and the adjacent needle
loop.
Calculation

                l2 = stitch length
               ks = Dimensional constant (dry relaxed, wet relaxed or finished relax )
           s = stitch density (wales/cm x course/cm)
Formula,
           s = ks/ l2
It can be written as,
                    l =  √ks/s             
According to this formula, previously calculated stitch density was applied with finished relaxed estate.
                               l = √2360/252cm-2
                                 = √9.36507
                                 = 3.0602 mm

(v) Calculation the knitted yarn length requirement to knit 5000m2 of fabric.

Description & Calculation

To find knitted yarn length requirement for 5000 m2  fabric we need to use previously found loop length and that can be written as,

                                      = loop length  x  stitch density
                                      = 3.0602 mm   x  252cm-2
   For 1 m2 fabric          = 3.0602 x 10-6  x  252 x 104 km
                                     = 7.71170 km
For 1000 m2 fabric       = 7.71170 km  x 1000
                                     = 7711.704 km
For 5000 m2 fabric       = 7711.704 km  x 5000m2/1000m2
                                     = 38558.52 km