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1. Textile Science
National Institute of Fashion Technology,
Gandhinagar

2. Objectives
2
To understand properties of textile fibers
To enlarge vocabulary of textile fibers
To keep up with advance in textile fibers
To grasp basic theory related to textile fibers

3. Course Syllabus
Textbook/
1. Fabric Science,by Pizatto, Allen
Cohen
2. Textile Fibers To fabric by Corbman
3. Understanding Fabrics from fibres to
finished cloth by Debbie and Giollo
4. Understanding Textiles by Phyllis G,
Tortora And Billie J Collier
5. Mordern Textiles by Dorothy Siegert Lyle
3

4. Grading
4
Grade
Attendance %
Homework %
Final exam

5. Topical Outline -1
5
Introduction to Textile Fibers
1
Natural Cellulosic Fibers
2
Natural Protein Fibers
3
Regenerated Fibers
4

6. Topical Outline -2
6
Synthetic Fibers
5
Absorption of Textile Fibers
6
Other properties of Textile Fibers
7

7. 1 Introduction to Textile Fibers
What is a fiber
 Large L/D
 Small ; flexible
Textile Fiber
 Length > 12.5 mm
 Strong ; processed

Fiber Yarn Textile
7

8. 1.1 Classification of Textile Fibers
8
Cellulosic fibers
Protein fibers
Mineral fibers
Regenerated fibers
Synthetic fibers
Mineral fibers
Nature
fiber
Man-made
fiber

9. 1.1.1 Natural cellulosic fibers
Seed fibers:
Bast fibers:
Leaf fibers:
Nut fibers:
9
cotton, kapok
jute, hemp, ramie, flax
Agave , pineapple, abaca
Coir

10. 1.1.2 Protein fibers
Animal-hair fibers:
Animal secretion:
10
wool, specialty hair, fur fibers
silk, spider silk

11. 1.1.3 Mineral fiber
 Asbestos
11
 A group of minerals
 Heat, electricity and chemical
damage resistance; sound absorption
 Highly toxic mesothelioma and
asbestosis.

12. 1.1.4 Regenerated Fibers
Regenerated cellulosic fibers
 Tencel
 Modal
 PLA
Regenerated protein fibers
 Soybean fiber
 Milk fiber
12

13. 1.1.5 Synthetic Fibers
Name Year Company
Nylon 1938 Du pont
Acrylic fiber 1950 E.I. Du Pont
Polyolefin/
polypropylene
1959
Hercules
Incorporated
Spandex 1961 E. I. Du Pont
13

14. 1.1.6 Fineness of Fiber
Gravimetric (Direct system)
Tex: Mass in grams of 1000 m of fiber
Denier: Mass in grams of 9000 m of fiber
Metric count Ne (Indirect system):
The length of meters per gram.
14

15. 1.1.7 Yarn Number System
15
Direct system
Tex
Indirect system
Den(ier)
Imp. count
Metric count

16. 1.2 Fiber polymer
Polymerization
Degree of polymerization
Average molecular weight of polymer
=
Molecular weight of thr repeating unit in the polymer
16

17. 1.2.1 Types of Polymer
17
Homopolymer
Copolymer

18. 1.2.2 Interpolymer Forces of Attraction
Van der Waals’ forces
Hydrogen bonds
Alt linkages
Cross-links
18

19. 1.3 Fiber Properties
19
Fiber properties
Physical
Mechanical
Chemical

20. 1.3.1 Physical Properties
20
Color
Luster
Shape
White or colorless
fibers and filaments
are preferred.
Varied in fibers
Be examined both
in cross section and
in its longitudinal.

21. 1.3.2 Mechanical Properties
21
Mechanical
Properties
Tensile Flexibility
Abrasion
Resiliency Pilling
Tenacity

22. 1.3.3 Chemical Properties
Absorbency
Effect of Heat
Flammability
Chemical Reactivity and Resistance
22

23. 2 Natural Cellulosic fibers
23
Stem
Natural Cellulosic fibers
Leaf Seed
flax
hemp
jute
ramie
sisal
abaca
cotton
kapok

24. 2.1 Introduction
24
Relatively high density
Good conductor of heat and electricity
Tend to burn easily
Good resistance to alkalis
Insects do not attack cellulosic fibers

25. 2.2 Cotton
25
Most widely used
Cotton
Grow in 80 countries
Ideal for textiles
Favorable personal
care items

26. 2.2.1 Cotton classification
26
Breed Process Luster
Upland
Island
Asian
African
roller
ginned
saw
ginned
White
Yellow
Grey

27. 2.2.2 Cotton Fiber Morphology
27
Cross-section
Longitudinal
section
Kidney-shaped Convolution

28. 2.2.3 Structure of Cotton Fiber
28
Cuticle Primary
wall
Secondary
wall
Lumen

29. 2.2.4 Polymer System
29
Linear cellulose polymer
Polymer
System
DP = 5000 Crystallinity = 65-70%
(C6H10O5)n

30. 2.2.5 Chemical Properties
30
Weakened and destroyed by acids
Resistant to alkalis
Relatively unaffected by laundering

31. 2.2.6 Physical Properties
31
Relatively inelastic
Physical
Properties
Very absorbent Conduct heat energy

32. 2.2.7 Growth and Production
32
Preparation
Planting
Crop
Harvesting
Ginning

33. 33

34. 2.3 Bast fibers
Be collected from Phloem (the "inner bark"
or the skin) or bast surrounding the stem
of a certain, mainly dicotyledonic plants.
34
Bast fiber
Flax
Ramie
Jute
Hemp

35. 2.3.1 Flax Fiber
35
Cellulose
Flax fiber
Bast
Multi-cellular Density = 1.50 g/cm3

36. 2.3.1 Flax Fiber Morphology
36
Cross-section
Longitudinal
section
Polygonal Nodes

37. 2.3.2 Polymer System
37
Cellulose polymer
Polymer
System
DP = 18000 Crystallinity > 70%

38. 2.3.3 Physical Properties
38
Very inelastic
Physical
Properties
Very absorbent Best heat resistance
Very strong

39. 2.3.4 Chemical Properties
39
Weakened and destroyed by acids
Resistant to alkalis
Relatively unaffected by laundering
Not mercerized

40. 2.3.5 Processing of Flax
40
Pulling
Retting
Breaking
Hackling
Spinning

41. 3 Natural Protein Fibers
41
Hair
Natural protein fibers
Secretion
wool
cashmere
mohair
rabbit hair
silk
tussah silk
spider silk

42. 3.1 Introduction
42
Be obtained from animal sources
Excellent moisture absorbency
Poor resistance to alkalis
Good resiliency and elastic recovery

43. 3.2 Wool
43
Wlna, wullo, wull
Wool
fleece of sheep
medium weight
multi-cellular
staple fiber

44. 3.2.1 Fiber Morphology
44
Cross-section
Longitudinal
section
oval over-lapping scale

45. 3.2.2 Felting of Wool
45
High resilience
Scales Directional
friction
Felting
Wet and heat
Dimensional
stability
Warm ,soft
√
×

46. 3.2.3 The Polymer System
46
Linear, keratin polymer
has a helical configuration
Unit of wool polymer is amino acid

47. 3.2.4 Structure of Wool
Wool fiber is composed of surface scale,
cortex and medulla layer.
47

48. 3.2.5 Chemical Properties
48
Resistant to acids
Dissolve readily in alkaline solutions
Yellow in sun and weather
Easy to dye

49. 3.2.6 Physical Properties
49
weak
Physical
properties
very absorbent low heat resistance
excellent resilience

50. 3.3 Specialty hairs
Mohair
Cashmere
Camel Hair
Alpaca
Llama
Vicuna
50

51. 3.3.1 Mohair
Mohair refers to the hair of
Angora goat.
Mohair fiber is approximately
25-45µm in diameter. It is
both durable and resilient. It
is notable for its high luster.
51

52. 3.3.2 Cashmere
Cashmere is a type of fiber
obtained from the Cashmere
goat, or Pashmina.
cashmere fiber is highly
adaptable.
Cashmere is similar to wool
in most properties.
52

53. 3.3.3 Camel Hair
Camel-hair are both light in
weight and warm; they have a
distinctive golden brown colour
with a pleasing lustre. The
fabrics are soft, comfortable, and
good wearing, and they drape
attractively.
53

54. 3.3.4 Alpaca
Alpaca offers excellent warmth and
insulation. The fibres are strong and glossy
and make fabrics similar in appearance to
mohair.
54

55. 3.3.6 Llama
Llama fibre is soft, strong,
and relatively uniform in
length and diameter but
somewhat weaker than
alpaca or camel hair.
55

56. 3.3.7 Vicuna
Vicuna is one of the
softest fibres in the world.
It is fine and lustrous, has
a lovely cinnamon brown
or light tan colour, and is
strong enough to make
very desirable fabrics. It is
also very light in weight
and very warm.
56

57. 3.4 Silk
57
secretion of silkworm
Silk
medium weight
density
1.34 g/cm3

58. 3.4.1 Fiber Morphology
58
Cross-section
Longitudinal
section
rounded triangle smooth

59. 3.4.2 Polymer System
59
linear fibroin polymer
sixteen different amino acids
not contain sulphur
only in beta-configuration

60. 3.4.3 Chemical Properties
60
More readily affected by acids
Swell in alkaline solutions
Be affected by bleaches
Resistance to sunlight is poor
Compared with wool

61. 3.4.4 Physical Properties
61
strong
Physical
Properties
more sensitive to heat
more plastic than elastic

62. 3.4.5 Silk Production
62

63. 4 Regenerated Fibers
63
Natural material
Dissolve
Extrude
Wood, cotton
Regenerated fibre Viscose, acetate, triacetate

64. 4.1 Viscose Fibres
64
viscose
rayon
cellophane
viscose fibre
Viscose process was discovered and patented
in 1891 by C. F. Cross and E. J. Bevan.

65. 4.1.1 Manufacture
pulp
alkali cellulose
xanthate cellulose
viscose
viscose filaments
65

66. 4.1.2 Modified Viscose Fibres
66
HVM rayon
modified rayon
HT rayon
high wet modulus
HWS rayon
high wet strength High tenacity

67. 4.1.3 Polymer System
67
cellulose polymer
Polymer
system
amorphous 65-60% crystallinity 35-40%

68. 68

70. 4.1.4 Physical Properties
70
weak
Physical
properties
most absorbent low heat resistance
limp

71. 4.1.5 Chemical Properties
71
similar to cotton
sensitivity to acid, alkali, bleach, sunlight
color more brightly

72. 4.2 Acetate and Triacetate
72
Cellulose
Acetate
Triacetate
acetylize
textile
filtration

73. 4.2.1 Structures
73
DP= 250-300
Structures
Skin-core structure
Cross-section: lobed

74. 4.2.2 Properties
74
Acetate Triacetate
hydrophilic
thermoplastic
hydrophobic
high crystallinity
Wrinkle easily in hot water
Swells in water
Resist to weak alkali and acids

75. 5 Synthetic Fibers
75
coal natural gas
petroleum
extrusion
spinnerets
Synthetic Fibers

76. 5.0 Types of spinning methods
76
melt polymer to a
viscosity suitable for
extrusion
polymer solution is
extruded into gas or
vapor
Melt
Spinning
Dry Solvent
Spinning
Wet Solvent
Spinning
Polymer solution is
extruded into a
precipitation bath

77. 5.1 Nylon
77
February 28, 1935
Wallace Carothers
Nylon
thermoplastic
silky material
polyamides
DuPont

78. 78

79. 5.1.1 Types
79
mostly
small amount
Nylon 6
Nylon 6,6
Nylon 3, Nylon 4, Nylon 5,
Nylon 7, Nylon 8, Nylon 12,
Nylon 4,6, Nylon 6,10

80. 5.1.2 Structures
80
linear zigzag molecules
structures
crystallinity:65~86%
H-bond
amide group

81. 5.1.3 Properties
Tenacity: high due to high orientation and
crystallinity
Elongation: high due to zigzag structure
Recovery: high due to zigzag
Energy of rupture: high due to high tenacity and
high elongation.
Abrasion resistance: high
Water absorption: highest among all synthetic
fibers
81

82. 5.1.3 Properties
82
high tenacity
high elongation
high recovery
high abrasion resistance
highest water absorption

83. 5.2 Polyester
83
DuPont, 1945
Polyester
versatility
Dacron, Tetoron
Terelenka, Lavsan
the largest volume
聚酯

84. 5.2.2 Types
84
Polyethylene terephthalate
Polybutylene terephthalate
PET
PBT
PTT Polybutylene terephthalate

85. 5.2.3 Fiber Morphology
85
Cross-section
Longitudinal
section

86. 5.2.4 Structures
86
DP =115-140
structures
crystallinity: 35%
even diameter
very oriented

87. 5.2.5 Properties
87
high tenacity
high failure elongation
low compressional resilience
very low moisture regain
high electrical resistivity

88. 5.2.6 Modification
88
High tenacity
higher crystallinity
and DP
Sheath-core
polyester core, low
melt polymer sheath
Coolmax hydrophilic treated
Wicking

89. 5.3 Acrylic
89
1950, DuPont
Acrylic
synthetic wool
Perlon, Orlon

90. 5.3.1 Polymerization
Addition or chain growth
Homopolymer: polyarylonitrile strong but
compact and highly oriented
 virtually impossible to dye
Copolymers: other types of monomers are
included for a dyeable fiber and easier to
process:
 e.g. acrylic acid and vinylpyrrolidone
 most acrylic fibers are copolymers
90

91. 5.3.2 Fiber Morphology
Cross-section
Longitudinal
section

92. 5.3.3 Properties
92
medium tenacity
medium failure strain
high elastic recovery
moderate abrasion resistance

93. 5.4 Elastomeric
93
polyurethane-based
Elastomeric
lightest apparel fibre
H2NCONH2

94. 5.4.1 Fibre Morphology
Longitudinal appearance has distinct
striations and specks.
Cross-section of fiber has the dump-bell or
dog-bone shape
94

95. 5.4.2 Polymer System
Two types of elastomeric polymers are
synthesized. Each is extruded into
filaments with excellent elastic properties
but differing in their resistance to alkalis.
The polyether type (for example Lycra)
resistant to alkalis
The polymer type (for example, Vyrene)
95

96. 5.4.3 Physical Properties
96
weak tenacity
excellent recovery
hydrophobic
thermo-plastic

97. 5.4.4 Chemical properties
Effect of acids: Elastomeric textile material
in general are resistant to acids.
Effect of alkalis: The elastomeric is
sensitive to alkalis.
Colour-fastness: Elastomeric textile
material tend to be difficult to dye owing
to the hydrophobic and very crystalline
nature of their polymer system.
97

98. 5.4.4 Chemical Properties
98
resistant to acids
Chemical
properties
difficult to dye
sensitive to alkalis

99. 6.1 Introduction of Absorption
Adsorption in a non-swelling medium, for
example, the adsorption of gases on
charcoal, is a comparatively simple
process, but the absorption of water by
fibers is an example of a process that
comes midway between these two and
partakes of some features of each.
99

100. 6.2 Equilibrium
When a textile material is placed in a
given atmosphere, it takes up or loses
water at a gradually decreasing rate until
it reaches equilibrium, when no further
change takes place. This is a dynamic
equilibrium.
100

101. 6.3 Regain and relative humidity
Relative humidity(RH)=
p(H2O)－Partial pressure of water vapor
p*(H2O)—Saturation vapor pressure
Regain
G － Mass of undried specimen
G0 －Mass of dried specimen
2
*
2
(H O)
100%
(H O)
p
p

0
0
100%
G G
W
G

 
101

102. 6.3 Regain and relative humidity
102
0
0
100%
G G
W
G

 
2
2
(H O)
*
(H O)
100%
p
p


103. 6.4 Theories of moisture sorption
Sorption refers to the action of either
absorption or adsorption. As such it is the
effect of gases or liquids being
incorporated into a material of a different
state and adhering to the surface of
another molecule.
103

104. 6.4.1 The effect of hydrophilic groups
As absorption, we take account of interac-
tion between water molecules and molec-
ules of the fiber. All the natural animal
and vegetable fibers have groups in their
molecules that attract water, such as –NH2,
—CONH, —OH, —COOH.
104

105. 6.4.2 Directly and Indirectly Attached Water
The first water molecules are absorbed
directly onto hydrophilic groups, but, for
the others: They may be attracted to other
hydrophilic groups, or they may form
further layers on top of water molecules.
H2O H2O H2O
H2O H2O H2O
Fiber
Direct
Indirect
H2O H2O
105

106. 6.4.3 Absorption in crystalline regions
In crystalline region, the fiber molecules
are closely packed together in a regular
pattern. Thus it will not be easy for water
molecules to penetrate into a crystalline
region, and, for absorption to take place,
the active groups would have to be freed
b y t h e b r e a k i n g o f c r o s s - l i n k s .
106

107. 7 Other Properties of Textile Fibers
107
Thermal
Electric
Optical
Performance of
processing and
usage of textile
fibers

108. 7.1 Thermal properties
Thermal conductivity is a property of
materials that express the heat flux(W/m2)
that will flow through the material if a
certain temperature gradient DT(K/m)
exists over the material.
Fiber material Thermal conductivity[mW/(m.k]
Cotton 71
Wool 54
Silk 50
108

109. 7.1.1 Specific Heat Capacity
109
Q
C
m T


Specific heat capacity
(J/(g˙℃)
Heat, （J）
Temperature(℃)
Mass(g)
moisture
temperature
fiber structure
C

110. 7.1.2 Coefficient of Heat Conductivity
110
Q d
T t s



  
Coefficient of heat
conductivity
(W/(m˙℃) Conduction surface
（m2）
Temperature difference
℃)
Heat, (J） Thickness, (m）
Time,(t）

111. 7.2 Optical properties
When light falls on a fiber, it may be partly
transmitted, absorbed or reflected.
Refractive index niso of an isotropic fiber is
given by the mean of the refractive indices
of an oriented fiber in 3 directions:
 Polarized parallel to fiber axis
 Polarized perpendicular to fiber axis
1/ 3( 2 )
iso
n n n
 
n
n
111

112. 7.2 Optical Properties
112
Optical
properties
luster
reflection
refraction
transmission
light
degradation
resistance

113. 7.2.1 Luster
113
Light on collection of fibers
Laminate structure
Longitudinal morpha
Cross-sectional shape
Luster

114. 7.2.2 Birefringence
Birefringence, or double refraction, is the
decomposition of a ray of light into the
ordinary ray and the extraordinary ray
when it passes through certain types of
material.
114
n n n
  
P
Birefringence index
Refractive index for light polarized parallel
(perpendicular)to the fiber axis.

115. 7.3 Electric properties
The electronic properties of fibers are of
less importance than the mechanical
properties.
115
electric
conduction
dielectric
static electricity

116. 7.3.1 Electric Conduction
116
Surface
resistivity
Volume
resistivity
Mass
resistivity
Fiber
Cotton 6.8
Ramie 7.5
Silk 9.8
Wool 8.4
Viscose 7.0
Fiber
Polyamide 9-12
Acetate 11.7
Acrylic 8.7
Polyester 8.0
lg m
 lg m


117. 7.3.2 Dielectric
117
Fiber is dielectric material.
0
r
C
C
 