This ppt gives an introduction to the types of fibers along with the primary and secondary properties needed by any material to be classified as a fiber

1. INTRODUCTION
TO FIBRES
DR. RITU MADHAN

2. TEXTILES
The word ‘textile’ comes from the Latin word ‘textilis’
and from the verb ‘texere’, which means ‘to weave’.
Today the word textiles is used freely to define any
product made from fibers and is applied to non-
woven fabrics, knitted fabrics as well as woven
fabrics.
The broad definition of word textiles is applied to
everyone who works with fibers or fabrics at any
stage of manufacture or processing

3. FIBER
CLASSIFICATION

4. FIBER
CLASSIFICATION
Natural fibers
Plant
Cotton Jute Linen Hemp Kapok Pina
Animal
Silk Wool
Hair
bearing
animals
Mineral
Asbestos

5. FIBER
CLASSIFICATION

6. Name any one natural and one
synthetic fiber

7. FIBER PROPERTIES
(PRIMARY)
• Length must be greater than
the diameter
• Fibers less than ½ inch in
length cannot be used for
spinning
Length to
width
ratio
• Tenacity is the force applied to
a fiber
• Fibers should be durable
enough to last the tension of
conversion to yarn and then to
fabric
Tenacity

8. FIBER PROPERTIES
Elasticity
• Elasticity the ability
of the material to
regain original
shape after being
deformed by the
application of force
• Elasticity or elastic
recovery are
generally influenced
by the extent of
stretch, time during
which material is
kept in its stretched
condition and time
to recover
Uniformity
• It is essential that
there should be
limited variations in
length and diameter
between fiber to
fiber or in other
words the fiber
should be more
uniform which will
ensure uniformity in
the yarn as well as
fabric
Spinnability
• Fibers must be
capable of being
spun into a yarn
and then a fabric
with sufficient
strength.
• For better
cohesiveness i.e.
they must hold
themselves together
to prevent slippage.

9. FIBER PROPERTIES
(SECONDARY)

10. FIBER PROPERTIES
(SECONDARY)
• It is the ability of the fiber to bounce back or return
to shape after compression, bending or similar
deformation. It is important in determining the
crease recovery of a fiber or fabric. Usually good
elastic recovery indicates good resiliency.
RESILIENCY
Textile fibers in general have certain amount of
moisture as an integral part of the fiber structure.
ASTM defines, moisture regain as ‘the moisture in
a material determined under prescribed condition
and expressed as percentage of the weight of the
oven dry specimen.
MOISTURE
REGAIN AND
MOISTURE
ABSORPTION

11. REQUIREMENTS FOR FIBER -
FORMING POLYMERS
• Fiber polymers should be hydrophilic i.e. they should
attract water molecules. A fiber is comfortable to wear if
its polymer system consists of hydrophilic polymers, and
the system permits they entry of water molecules.
HYDROPHILIC
PROPERTIES
• Fiber polymers should be chemically resistant for a
reasonable length of time against the common
degrading agents . Chemically resistant polymers
should also not be toxic or hazardous to wear against
the human skin.
CHEMICAL
RESISTANCE
• Fiber polymers should be linear. Only linear polymers
allow adequate polymer alignment to bring into effect
sufficient inter - polymer forces of attraction to give a
cohesive polymer and hence a useful textile fiber.
LINEARITY

12. REQUIREMENTS FOR
FIBER - FORMING
POLYMERS
LENGTH
Fiber polymers should be
long. It is found that the
length of the polymers
constituting the commonly
used apparel fibers is in
excess of 100 nanometers.
Polymers of such length
can be easily oriented. The
longer the polymers, the
more cohesive will be the
fiber system and the
stronger will be the fiber.
ORIENTATION
Fiber polymers should be
capable of being oriented.
This means that the
polymers are or con be
arranged or aligned into
more or less parallel order
in the direction of the
longitudinal axis of the
fiber or filament.
FORMATION OF HIGH
MELTING- POINT
POLYMERS SYSTEMS
A fiber consisting of this
system tends to have
adequate heat resistance
to enable it to stand the
various heat systems of
textile finishing. A fiber’s
melting point needs to be
above 225°C if it is useful
for textile manufacture and
apparel use

13. Which is the most important
property for a textile fiber?

14. Fiber Length, since short fibers
cannot be twisted to form a yarn
and in turn fabric!

15. POLYMERIZATION
Textile fibers like most
substances are made up of
molecules. Fiber molecules
are called polymer.
The unit of a polymer is called
monomer.
At the molecular level the
polymer is extremely long and
linear, whereas a monomer is
very small.
Monomers are usually reactive
chemically whereas polymers
tend to be unreactive.
This is illustrated by chemical
reaction called polymerization,
which causes the monomers
to joint from end to end.
The length of the polymers is
most important. All fibers both
man made and natural have
long too extremely long
polymers
Measuring the length of a
polymer is a complicated if not
impossible task.
Estimates of the length of a
polymer can be obtained by
determining the degree of
polymerization. This is often
abbreviated as DP.
A polymer is often described a
having a back bone consisting
of the atoms, which are
bonded to each other in a
linear configuration and are
responsible for the length of
the polymer.

16. POLYMERIZATION
Addition polymerization
• The monomers add or join end to
end without liberating any by-
product. Addition polymerization
is composed of 3 distinct steps:
• Initiation
• Propagation
• Termination
• The process is initiated through
the presence of activated
molecule introduced into the
system.
Condensation polymerization
• The monomers join end to end
and liberate a by-product. This
by-product is usually a simple
compound- generally water - but
it may alternatively be hydrogen
chloride or ammonia depending
upon the specific monomers
involved.
• This polymerization is expressed
as:
• n X M → Mn + (n-1)A
• Where, n - no. of monomers
reacting together.
• M - Monomer
• A - Simple molecule

17. MOLECULAR
ARRANGEMENT
• When the molecules are highly oriented, they are parallel to
each other and to the longitudinal axis of the fiber. Molecules
may exhibit low degree of variation associated with a good
fiber strength and low elongation. Low orientation tends to
reverse properties.
Oriented
• In contrast to orientation, crystalline arrangement indicates
that the molecules are parallel to each other but not to the
fiber axis.
Crystalline
• When molecules have no systematic arrangement, they may
lie far from each other, criss-cross, or in other irregular ways.
The extent of amorphous area varies widely from slight
disorder to extremely amorphous arrangement depending
upon the fiber and the location within the fiber.
Amorphous

18. MOLECULAR
ARRANGEMENT
Oriented Crystalline Amorphous