2. RAYON
(A Cellulosic Man-Made Fiber)
Composition Regenerated cellulose
Physical Properties
Microscopic Appearance
- Striations seen in viscose and high-strength rayon
- If DE lustered, scattered specks of pigment can be seen.
Length
- Filament and staple Color
- Transparent unless dulled by pigments
Luster
- High unless DE lustering pigment added
Strength
- Fair to excellent
- Regular rayon has fair strength
- High tenacity types have well to excellent strength
Elasticity
- Regular rayon is low
- High strength rayon is good
Resiliency
- High wet-strength rayon is better
Moisture Absorption
- Higher than natural cellulose
- Fibers swell in water
- Weaker when wet
Heat
- Loses strength above 300' F
- Decomposes between 350 and 400' F
Flammability
- Burns rapidly unless treated
Electrical Conductivity
3. - Fair and static charge can be reduced with special finishes
Specific Gravity - 1.52 (similar to cotton)
ACRYLIC
(A Wool-Like Fiber)
Composition
Acrylonitrile and small amounts of other monomers
Physical Properties
Microscopic appearance
- Uniform and smooth surface
- Irregular spaced striations
Length
- Mainly a staple fiber Color
- White to off-white
Luster
- Bright, semi dull, or dull
Strength
- Fair to good strength
Elasticity
- Good
Resilience
- Good –
Water Absorption
- 1-3%
Heat
- Yellowing may occur above 300' F
- Softening or sticking about 450' F
Flammability
- Burns with yellow flame
Electrical Conductivity
- Fair to good
4. Specific Gravity
- 1.14 to 1.19
- Good bulk and covering power
NYLON
(A Polyamide Fiber)
Composition
Nylon 66
- Polyhexamethylene Adipamide Nylon 6
- Caprolactam
Physical properties
Microscopic Appearance
- Very smooth and even
Length
- Filament and staple
Color
- Off-white
Luster
- High natural luster can be controlled
Strength
- Exceptionally high (60,000 - 108,000) pounds per square inch
Elasticity
- Exceptionally high
Resiliency
- Very good –
Moisture Absorption
- 3.8%
Heat
- High resistance melts at 482' F
Flammability
5. - Melts slowly
- Does not support combustion
Electrical Conductivity
- Low, generates static
Specific Gravity - 1.14 (low density)
POLYESTER
(Most Versatile Fiber)
Composition
Combination of Terephthalic Acid or Dimethyl terephthalate and Ethylene Glycol
Physical Properties
Microscopic Appearance
- Smooth, even, rod like, different cross-sectional shapes
Length
- Filament and staple
Color
- White
Luster
- Bright or dull
Strength
- Good to excellent
Elasticity
- Fair to good
- Greater than cotton or rayon
Resilience
-Excellent _
Moisture Absorption
- Less than 1%
Heat
- Softening or sticking temperature is above 400' F (thermoplastic)
6. Flammability
- Bum slowly
Electrical Conductivity
- Accumulates static changes
Specific Gravity
- Typically 1.38
ACETATE
(A Cellulosic Man-Made Fiber)
Composition
Acetate Ester of Cellulose
Physical Properties
Microscopic Appearance
- Striations farther apart than viscose rayon
- Lobed cross-section
Length
- Filament and staple
Color
- Transparent unless dulled by pigments
Luster
- Bright, semibright, or dull
Strength
- Moderate
- Less than rayon when wet
Elasticity
- Not very high
- Similar to rayon –
Resilience
- Poor
Moisture Absorption
- 6%, little strength loss when wet
7. Heat
- Ironing temperatures of 275' F are satisfactory
Flammability
- Slowly combustible
Electrical Conductivity
- Good
Specific Gravity - 1.32
POLYPROPYLENE
(An Olefin Fiber)
Composition
Propylene
Physical Properties
Microscopic Appearance
- Smooth and rod like
Length
- Filament and staple
Color
- Translucent
Luster
- Dull, semi dull, bright
Strength
- Excellent strength (depends on degree of polymerization)
Elasticity
- Good Resilience
- Good resistance to crushing
Moisture Absorption
- None
Heat
- Melts at about 330' F
8. - Progressive shrinkage can occur at 140' F to 212' F
Flammability
- Slow burning
Electrical Conductivity
- Excellent
Specific Gravity
- 0.90 to 0.91
POLYETHYLENE
(An Olefin Fiber)
Composition
Ethylene
Physical Properties
Microscopic Appearance
- Smooth and rod like
Length
- Filament and staple
Color
- Translucent
Luster
- Dull, semi dull, bright
Strength
- Fair to good (depends on degree of polymerization)
Elasticity
- Good Resilience
- Good resistance to crushing
Moisture Absorption
- None
9. Heat
- Very heat-sensitive
- Melts at about 260' F
Flammability
- Slow burning
Electrical Conductivity
- Excellent
Specific Gravity
- 0.90 to 0.91
SILK FIBRE
Silk is a natural fibre that is a solidifies protein secretion produced by certain
caterpillars.
Physical Characteristics:
The fibre is a fine continuous strand unwound from the cocoon of silkworm.
Silkworms are generally cultivated. The fibre can be fine and coarse, is lustrous,
smooth, light weight, strong and elastic.
Specific gravity
- 1.342
Moisture- St. M.R
- 11%3
Strength- Tenacity
– Dry 4.3 g/d; wet = dry 924
Elasticity- Braking extension
– 23.4%
Recovery (%) – 525
Resiliency
- Moderate
Abrasion resistance
10. - Good
Dimensional stability
- Good
Applications:
Silk has been used since a long time for a number of applications including:
•
Home furnishings
•
Apparels
•
Upholstery
ASBESTOS FIBRE
Asbestos is a natural fibre sourced from minerals, i.e. varieties of rocks found in Italy, Canada and
South America.
Physical Characteristics
The soft, glossy, long and white fibres are pressed into sheets. Chrysolite asbestos has a fine and
long staple that has lot of strength and flexibility. The fiber does not burn, but melts at a
sufficiently high temperature. It is rustproof and acid proof.
Applications:
Asbestos has been used in making firefighting and fire resistant fabrics. It is used to manufacture
commercial furnishings including theater curtains, draperies etc.
11. COTTON FIBRE
Cotton is a natural fibre, growing in the seed pod, or boll of the cotton plant. The fibre is composed
of about 90 % cellulose and around 6% moisture. The rest consists of natural impurities.
Properties of cotton fibre:
Strength:
1. It is relatively strong.
2. Strength of fibre can be defined by the ability to resist of being pulled or torn apart when
undergoes to tension.
Elasticity:
Elasticity means the extent to which a fibre can be elongated by tension & then return to its
original shape.
52
Resilience:
1. It means the extent to which a fabric can be deformed by compression & return to its original
condition.
2.
Finishing process does a lot to improve wrinkle resistant quality of cotton goods.
12. Drapability:
1. It is concerned with the ability of fabric to hang easily & fall into graceful to shape &folds.
2.This quality depends on the kind of fibre, yarn, fabric construction & finish used to final goods.
Absorbency:
1. It determines the amount of moisture taken up by the fibre from air.
2. Cotton fibre is very absorbent.
3. Twist in the yarn also influences absorbency.
4. Low twist yarn absorbs more moisture than high twisted yarn.
5. Fabric structure also plays role in absorbency. Looser structure will be more absorbent than
tighter one.
Specific gravity
- 1.52
Tenacity
-4.0
Moisture Regain
-7.5
LINEN FIBRE
Linen is one of the oldest and a very popularly used fibre obtained from the stalk of the flax plant.
The hair like fibres, are held together by a gummy substance known as pectin. Linen is composed
of 70 percent cellulose, and 30 percent pectin, woody tissue, ash and moisture.
Physical Characteristics:
The fibre is smooth, straight and lustrous. It is more brittle and less flexible than cotton. The fibre
is also more difficult to spin into yarn. It has a long staple fibre length when compared to cotton
Properties of Linen
Linen has a number of properties, which makes it useful for various industrial applications, use in
home furnishings and apparels. Some of them are:
•
Strength:
Linen is a durable fibre, as is two-three times as strong as cotton. It is second in strength to silk.
•
Elasticity:
13. Elasticity is the extent to which a fibre can be elongated or stretched and the then returned to its
normal condition and size. Linen is the least elastic natural fabric.
•
Resilience:
Resilience refers to the extent to which a fabric can be deformed by crushing or compressing it,
and finally returning it to its original condition. Linen is quite stiff and wrinkles easily.
•
Absorbency:
Absorbency refers to the extent to which moisture can penetrate into a fiber. The fiber absorbs
moisture and dries more quickly. It is excellent for manufacturing towels and handkerchiefs.
•
Heat Conductivity
:
Heat conductivity refers to the extent to which heat can be conveyed through a fibre. It is most
suitable for use in summers, as the fibre allows the heat to escape, leaving a cool effect.
Applications:
Linen is one of the widely used fibre used in:
•
Apparels
•
Home furnishings
•
Commercial furnishing
•
Upholstery
•
Industrial application
JUTE FIBRE
Known as the raw material for sacks all over the world. Jute is truly one of the most versatile fibres
gifted to man by nature that finds various uses in the form of Handicrafts. Next to cotton, jute is the
cheapest and most important of all textile fibres. Jute cultivation provides work for millions of
farmers, landless laborers, industrial workers and provides jobs for many others, indirectly.
Characteristics of Jute Fibre:
Jute is a long, soft, shiny fibre that can be spun into coarse, strong threads. It is one of the cheapest
natural fibers, and is second only to cotton in amount produced and variety of uses. Jute fibres are
composed primarily of the plant materials cellulose, lignin, and pectin. Both the fibre and the plant
from which it comes are commonly called jute.
Physical properties:
Specific gravity
14. - 1.482
Moisture – St. M.R
13.75 & absorb 35 – 40% water of its dry weight
Strength- Tenacity
-dry 3.5-5 g/d wet lower than dry
Elasticity-Breaking extension
– 1.8% Recovery (%) very low.
For high tenacity, less extension, high stiffness Jute fibres is brittle & can holds less twist. So
Emulsion is added to make it soft.
Specific heat is
- 0.3256
Resiliency
-bad
Abrasion resistance
-Moderate
Dimensional stability
-good
WOOL FIBRE
Wool is a natural fibre sourced from animals. It grows from the skin of sheep, goats. Rabbit and
alpacas are also used for producing high quality wool. This natural fibre is composed of a protein
known as Keratin and is a relatively coarse fibre.
Physical Characteristics:
The fibre is wavy, crimpy and has scales on its surface. The appearance of wool varies, depending
on the breed of sheep. While some fibres can be having finer scales, others can have crimp and
coarser scales. Wool fibre is susceptible to heat and has a felting property, caused due to the scales
on the surface.
15. Physical properties of wool:
Strength:
1. Wool is the weakest of the natural textile fibres.
2. Wool fibre is strengthened by the used of ply yarns.
3. A hard twisted two ply yarn may be regarded as an assurance of durability.
4. Tightly twisted single yarns also make a strong fabric.
Elasticity:
1. Depending upon the quality of wool, the fibre may be stretched from 25-30 percent of its natural
length
.2.This characteristic reduces the danger of tearing under tension.
3. This characteristic contributes to the free body movements
4. Wool & wool blend fabrics are given mechanical & chemical treatment to increase their
elasticity & provide better two ways stretch.
5. The chemical treatment also gives better shape retention.
Resilience:
1. Wool fibre has a high degree of resilience.
2. Good quality wool is soft & resilient
.3.Poor quality wool gives a harsh feeling.4.Due to the high degree of resiliency, wool fabric
wrinkles less than some others.
Drapability:
It has excellent draping quality due to its pliability, elasticity, and resiliency.
Effect of heat:
1. Wool becomes harsh at 100˚C & begins to decompose at slightly higher temperature.
2. It has plastic quality which helps to have shape at melting temperature.
Specific gravity
- 1.31
Tenacity
-1.6
Moisture Regain
-14 to 18
Effect of light:
Wool is weakened by prolonged exposure to sunlight.
Applications:
Wool is used for manufacturing various products including:
