About Textile fiber theory

2.  Textile Fiber is a smallest part of the fabric.
 This single hair like strand of fabric is called a fiber.
They are the basic building block used in
manufacturing fabric. It can be called a body that is
very long in relation to the thickness.
Uses of Textile fibers & fabrics
 Apparels
 Home furnishings
 Household textiles
 Building Trades

5. Classification based on Length of fibers:
Fibers come as short fibers and long fibers and their
length is an important property of fibers.
 Staple fiber- is a unit of matter which is usually at least
100 times longer than it is thick. They are short length fibers.
All natural fibers like cotton, flax, wool except silk are staple
fibers.
 Filament fiber- is a very long fiber. The length of
filaments may range from a few 100mts e.g. Silk to
several km, all Manmade fibers.
Classification based on source of fibers:
 Natural Fibers- are those which are obtained from
different sources of the nature.
Three Sources:
 Vegetable/ plant
 Animal

6.  Mineral
Part of the Plant-
 Seed- Cotton
 Bast / Stem- Jute, Linen
 Leaf- Sisal
 Fruit- Coir
 Animal- Silk, Wool
 Mineral- Asbestos.
II) Manufactured Fibers –
 Regenerated fibers- manufactured from any of the
natural source eg., cellulose, (waste cotton fibers or
wood pulp) or protein treated with different types of
chemicals.
 E.g. - Rayon –regenerated cellulose fiber.

7.  Synthetic fibers- are produced from
chemicals by combining carbon, oxygen,
hydrogen & other simple elements into larger
complex molecular combinations called
polymers. E.g. - Nylon, Polyester, acrylic
 Metallic fibers- are produced by mining &
refining metals such as aluminum, silver &
gold.

8. IDENTIFICATION OF FIBERS-
 Visual Inspection- Can identify a fabric by its
appearance but accuracy in identifying comes
through experience. The appearance properties
of different fibers can help in identifying a fabric
e.g., Silk is smooth, shiny and fine.
 Cotton is also smooth but looks dull, wool is
most definitely rough.
 Burning Test- Burning test is a simple and
reliable test. The burning test does not identify
the fiber in particular but indicates its group.
Cotton, flax and rayon will have similar results
when burnt as they are all basically cellulosic in
nature.

9.  Cotton, Linen, Coir- Smell of burning paper
 Silk, wool- smell of burning hair.
 Chemical Test- final verification of fibers is
done by this test.

10. Acetone 100% Hydrochloric acid 20% Sulfuric acid 60% Sulfuric acid 70% Chlorine bleach 5% Formic acid 90%
ACETATE Soluble Insoluble Soluble Soluble Insoluble Soluble
ACRYLIC Insoluble Insoluble Insoluble
Insoluble
depending on type
Insoluble Insoluble
COTTON Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble
HAIR Insoluble Insoluble Insoluble Insoluble Soluble Insoluble
HEMP Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble
LINEN Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble
MODARYLIC
Soluble or Insoluble
depending on type
Insoluble Insoluble Insoluble Insoluble Insoluble
NYLON Insoluble Soluble Soluble Soluble Insoluble Soluble
OLEFIN Insoluble Insoluble Insoluble Insoluble Insoluble Insoluble
POLYESTER Insoluble Insoluble Insoluble Insoluble Insoluble Insoluble
RAMIE Insoluble Insoluble Slightly soluble Soluble Insoluble Insoluble
RAYON Insoluble Insoluble Soluble Soluble Insoluble Insoluble
SILK Insoluble Partially Soluble Soluble Soluble Soluble Partially soluble
Wool Insoluble Insoluble Insoluble Insoluble Soluble Insoluble

11. PROPERTIES OF FIBERS-
Primary Properties
A fiber must possess these to qualify as a suitable
substance for use in forming textile fibers. These
include:-
 Length to Width Ratio-
The fiber must be long enough to allow
processing & slender enough to be flexible.
 Strength (Tenacity)-
Fiber must possess enough strength to
withstand chemical or machine processing. It’s
related to durability of fiber & final product.

12.  Flexibility/Pliability-
The ability of a fiber to resist repeated bending
without rupture is flexibility or pliability.
Important for end use :
 Influence the hand/ feel.
 Draping/ falling quality of apparel & home
furnishing.
 Capacity to move with body& permit freedom
movement.
 Durability of end product.
 Cohesiveness or Spinning Quality-
 It is ability of fibers to adhere/ stick to each other or
cling together during yarn manufacturing process.

13.  Uniformity-
To convert fiber into yarn, a fiber must possess similar
length & width, cohesiveness, strength & flexibility. It
produces even yarns & fabrics of uniform appearance.
Secondary Properties-
 Physical Properties -
 Physical Shape-
This includes average length, surface contour, surface
irregularities & cross section.
 Fineness-
Relative sizes, Diameter are measures of fineness of the
fiber.
 Luster-
Luster is the gloss, sheen or shine that fiber possesses.
Determined by the way light is reflected from the
surface of the fiber.

14.  Effect of Cross sectional shape-
 Smooth surface reflect light back to their sources & appear
shiny.
 Silk has more regular surface so gives distinct luster.
 Colour-
Fibers are available in wide range of colors. White
or colourless fibers are preferred as they can be
dyed or printed with different colours.
E.g. Wool- off white, tan, brown, gray or black
 Cotton- usually white or cream
 Manmade- exist in wide range .
 Moisture Absorption-
The amount of water a fiber can absorb from the
atmosphere or water bath may affect apparel
comfort, fabric care, and textile processing & fiber
price.

15.  Fibers are usually categorized:
 Hydrophilic- Those ‘like’ or absorb water.
 Hydrophobic- those that ‘dislike’ or do not absorb water.
 Elongation & Recovery-
Elongation- the amount of stretch or extension
that a fiber will accept is referred as elongation.
Elastic recovery- it is the ability of a fiber to
recover its original length immediately after
removal of the load. If fiber recovers completely
from deformation, it exhibits 100% elastic
recovery.
 Resiliency-
The ability of fiber to return to its original shape
after compression, bending, creasing, twisting or
similar deformation is resiliency.

16.  Abrasion Resistance-
The wearing away of a material by rubbing against
another surface is known as Abrasion. Abrasion
around collars, cuffs in apparels occurs as fabric
move & rub against another surface, such as human
body, arm of a chair.
 Thermal Properties-
The reaction of a fiber to heat & flame are
considered its thermal properties. Most textile
fibers burn when exposed to a flame.
 Fiber with low incidence of burning will be safer
than fibers that burn quickly.
 Some fibers melt &drip- Nylon
 Self extinguisher – Wool, silk
 Glow afterwards- Cotton , Rayon

17.  Biological Properties-
Its behavior of fibers towards insects, beetles, moths,
microbes, bacteria, fungi, mildews etc.
 Chemical Property-
 Reaction to Bleaches-
 Bleaches are chemical solutions designed to remove
discoloration. Hydrogen peroxide is used.
 Reaction to Alkalies-
 Cellulosic- Not harm by alkalies.
 Protein- Harmful.

18.  Reaction to Acids-
Concentrated cold or dilute hot mineral acids
such as sulphuric acid, will destroy it-
 Cellulosic
 Wool
 Resistant to dilute acids.
 Although wool is damaged by hot sulphuric acid,
it is not affected by other acids, even when
heated.

19. NATURAL CELLULOSIC FIBERS-
 The natural cellulosic fibers are those that occur in fiber
form as parts of plants. Sometimes these are also called
Vegetable or Plant fiber.
 They are obtained from 4 plant parts: -Seed hair, Fruit
Husk, Plant stem & Plant leaf. Burn easily, give smell of
burning paper.
Cotton-
 It is obtained from seed hair & most widely used.
Kind & Types:
 Variations occur because of growth condition such as: -
Soil, climate, fertilizers & pests.
 The quality depends on:-
 colour ( degree of whiteness)
 length ( staple or filament)
 fineness
 strength

20.  Manufacturing Process of Cotton-
 Cultivation of Cotton-
Buds appear a few weeks after the plant emerges.
After 3 weeks
Creamy white blossoms
Pink to reddish purple
3 days
Petals fall off & get the ripened seed pod
Pod expand to form cotton ball

21. Pod expand to form cotton ball
50 -80 days
Ball opens
Fleecy cotton fibers appear

22.  Harvesting-
Harvesting is one of the final steps in the
production of cotton crops, it is one of the most
important. The crop must be harvested before
weather can damage or completely ruin its
quality and reduce yield.
Types:
 Hand
 Mechanical

23.  Ginning & Bailing-
Raw cotton contains seeds, leaf fragments, dirt
etc. Cotton seeds approx. weigh 2/3 of raw
cotton. Seeds are removed by Cotton Gin.
 Gin separates the fiber called cotton lint from
its seeds. Cotton fiber is compressed into
rectangular bales.

24. Properties of Cotton:
 Length to width ratio – 6000:1 (for longest & best) to
about 350 :1 for shortest & coarsest.
 Strength- Good
 Colour- Vary from near white to light tan. Depends
on climatic condition, soil, and environment.
 Elasticity- It is relatively inelastic. Cotton fibers
exhibit 75% elastic recovery at 2% extension.
 Resiliency- Cotton textiles wrinkle & crease readily.
 Drapability- It is ability of fiber to hang easily & fall
graceful shape& folds. Cotton drapes well.
 Absorbency- It is the ease with which moisture can
penetrate into fiber determines its absorbency.
Cotton has Good Absorbency.

25.  Thermal Property- It has relatively high degree
of heat conductivity. It Burns readily & quickly
with odour of burning paper. Long exposure
above 150 C gradually decomposes fiber. Safe
ironing temp.- 204 C for cotton.
 Chemical Property-
 Reaction to Bleaches- Bleaches are chemical solutions
designed to remove discoloration. Hydrogen peroxide is
used.
 Reaction to Alkalies- Not harm by alkalies
 Reaction to Acids- Concentrated cold or dilute hot
mineral acids such as sulphuric acid will destroy it.
 Cleanliness & Wash ability- Cotton attracts dirt
particles as it is rough. Resistant to alkalies
present in detergents so easy to wash.
 Effect of Light- Cotton fibers oxidize, turning
yellow & losing strength with prolonged exposure.

26.  Biological Property-
 Not attacked by most insects. It is susceptible
to attack of fungi & mildew. Only heavily
starched fabrics are likely to be attached by
silverfish.

27. Characteristics of Cotton Fabric –
 It is soft and comfortable.
 It has good strength.
 It is easy to handle and sew.
 It drapes well.
 It is flame retardant.
 It is machine-washable and dry-cleanable.
 It is hydrophilic, which means that cotton have
excellent absorbing capabilities. Garments made of
cotton absorb perspiration, thus keeping one more
comfortable.
 Cotton wrinkles easily. To resist this, cotton is being
blended with many other natural or synthetic fibers.

28. Uses of Cotton Fabric-
 Cotton Apparel / Garments - Garments made of
cotton are very soft, comfortable and weather
friendly. Normally all types of garments are made
of cotton fabrics; formal, casual and even industrial
clothing.
 Cotton Home Furnishing – Cotton home furnishing is
preferred because of the fabrics strength and
durability characteristics. E.g. - rugs or durries,
draperies and curtains, bedding products, etc.
 Cotton Handbags and Luggage – Due to strength,
cotton handbags and luggage are more widely
preferred. The heavier cotton fabric is used in these
kinds of products.

29.  Cotton Canvas- Medium to heavyweight cotton
fabric is used in range of canvas products like
shoes, tents, etc. Apart from these, cotton fabrics
are also used in medical and surgical products,
bookbinding cloths.