Types of fibres,their classification,applications,properties, and structures Further more polymers,their types and different type chemical bonds present in fibres,

1. Fiber Science
Fiber Science is the study of the formation, structure, and
properties of fibers on micro to macroscopic levels.
The study of fibrous materials and their use in a variety of
conventional and non-conventional applications.

2. Type of fibers
1- Manmade/Manufactured
a)- Synthetic ( Nylon, polyester, acrylic)
b)- Regenerated ( Rayon)
2- Natural Fibers
a)- Cellulosic origin
b)- Protein origin

3. Fiber Length
Length of fiber Class
Unit of
measurement Appearance
Long Filament fibers Yards/meters
Short Short fibers Inches/centime
ters
Classification of fibers on the basis of length

4. Fiber Applications
Home
Textile
Technical
Applications
Apparel

5. Apparel
Applications

6. Home Textiles

7. Technical Textiles

8. Fiber Science
Properties of fibers
1-Physical Properties
2-Chemical Properties
3-Mechanical Properties

9. Fiber Science
Physical Properties of fibers
Length
Fineness
Crimp
Maturity
Toughness
Elongation
Lusture etc.

10. Fiber Science
Mechanical Properties of fibers
Strength
Elasticity
Extensibility
Rigidity

11. Fiber Science
C) Chemical Properties
Solubility in aqueous salt
Solubility in organic salt
Chemical composition

12. Chemical structure of synthetic fibers
Monomers Vs Polymers

13. Synthetic Fibers
Monomer Vs Polymer
(Polyethylene terephthalate (PET)

14. Synthetic Fibers
Nylon 6 is synthesized by polymerization of caprolactam
caprolactam Nylon 6

15. Synthetic Fibers
Polyester is formed by Poly-condensation of PET monomer

16. Synthetic Fibers
In PET fibres, the molecules are mainly arranged in fiber, film and
in package form

17. Flax

18. Cotton

19. Silk

20. Wool

21. Cashmere and Mohair

22. Synthetic Fibers
• Rayon –1st artificial fiberfrom wood
• Acetate – artificial from wood (satin)
• Nylon –1st synthetic fiber
• Olefin – synthetic (carpet)
• Acrylic – synthetic wool
• Polyester – most common syn.
• Specialty fibers – Kevlar, Spandex

23. Rayon

24. Acetate

25. Nylon

26. Olefin and Acrylic

27. Polyester

28. Manufactured fibers
Manufactured (MF) fibers (formerly termed “man-made”) are formed
from a suitable raw material as a thick, sticky liquid, which is “spun”
or extruded through spinneret holes, forming streams that are
solidified into fibers
The raw material for MF fibers may be itself a natural substance, or it
may be synthetic (synthesized from basic chemical units), but it is
converted into textile fibers by a manufacturing process
While there are MF fibers made of natural rubber (as well as of
synthetic rubber), there is no such thing as a natural rubber fiber.
Similarly, Tencel lyocell is not a natural fiber; it is an MF fiber made of
a natural material, cellulose

29. Textile fibers are made up of molecules, these fiber molecules
are called polymers.
 The Unit of polymer is called monomer ( mono-one: mer-part)
At molecular level, polymer is extremely long and linear
whereas monomer is very small
Monomers are usually reactive whereas polymers tend to be
unreactive
This causes the monomers to join end to end to form a polymer
called polymerization

30. Polymerization

31. Length of polymer is most important. All fibers, both natural and man
made have long to extremely long polymer lengths
Measuring length of polymer is complicated yet not impossible
Degree of polymerization (DP) is therefore calculated
Degree of Polymerization=
Average molecular weight of polymer
Molecular weight of the repeating unit in the polymer

32. • 5000 DP for cotton means 5000 repeating units (cellobiose)
• Polymerization of natural polymers are not known
• Polymerization of synthetic polymer is categorized into
a. Addition Polymerization
a. Condensation Polymerization

33. a)- Addition Polymerization
Monomers add or join end to end without liberating any by product on
polymerization.
Some fibers which consist of addition polymerization are acrylic,
modacrylic, polyethylene, polypropylene etc.

34. b) Condensation Polymerization
In this process monomers join end to end and liberate a by
product
This product is a simple compound, e-g water, ammonia,
hydrogen chloride
 Some fibers consisting of condensation polymerization are
elastomeric, nylon and polymers.

35. • Polymers of cotton, acetate, flax, silk, triacetate, viscose and
other regenerated fibers and wool don’t fit into above
classification because not enough is yet known about their
polymers and synthesis

36. Types of polymers
1-Homopolymer ( Same or one kind of polymer)
2-Copolymer ( Two or more different polymers)
Copolymers are further divided into
i. Alternating copolymer
ii. Block Polymer
iii. Graft Polymer
iv. Random polymer

37. Types of Polymer
Homopolymer
Homos is “same” or one kind of polymer
Nylon, vinyl chloride, polypropylene

38.  The lack of branches in its structure
allows the polymer chains to pack closely
together, resulting in a dense, highly
crystalline material of high strength and
moderate stiffness.
 500,000 atomic units for High Density
Polyethylene

39. Copolymer
Polymerized from two or more monomers
• Silk is composed of 16 different amino acids
• Wool is composed of 20 different amino acids
 Copolymers are sub categorized into four groups

40. A thermoplastic resin produced by the
copolymerization of styrene and maleic
anhydride
A rigid, heat-resistant, and chemical-resistant
plastic, it is used in automobile parts, small
appliances, and food-service trays
most of the copolymers contain about 5 to 20
percent maleic anhydride, depending on the
application, and some grades also contain
small amounts of butadiene for better impact
resistance.
Alternating copolymer

41. 41
Copolymers can be used to tailor functionality or generate
new behaviors.
Block copolymer, example:
Poly(styrene)-block-poly(butadiene)
Random copolymer, example:
Poly(styrene-ran-butadiene)
Graft copolymer,
example:
Poly(styrene)-graft-
poly(butadiene)

42. 42
Combs, brushes and ladders give you ways to stiffen a polymer.

43. 43
Rod like polymers are used for very high strength, liquid
crystals, efficient viscosification
S
N
S
N
* *n
Rodlike because of helix
Rodlike because of linear backbone

44. Crystalline and amorphous
regions
Crystalline regions provide
strength and amorphous regions
provide stretch
Amorphous and crystalline regions

46. (a) Linear structure; thermoplastics such
as acrylics, nylons, polyethylene, and
polyvinyl chloride have linear structures.
(b) Branched structure, such as
polyethylene.
(c) Crosslinked structure; many rubbers
and elastomers have this structure.
(d) Network structure, is highly cross-
linked; examples include thermosetting
plastics such as epoxies and phenolics.

47. Possible arrangement of monomers in a polymer

48. Chemical Bonds
The basic nature and reactivity of the fiber can be derived by
the type of chemical bond that holds the polymers together
A chemical bond is an attraction between atoms that allows
the formation of chemical substances that contain two or more
atoms
The bond is caused by the electromagnetic force attraction
between opposite charges, either between electrons and nuclei,
or as the result of a dipole attraction

49. Classification of Bonds
Chemical bond can be broadly classified as follows
• Intra-polymer bonds
• Inter-polymer bonds

50. Intra-polymer Bonding
• Bonds holding the atoms together to make up the fibre polymer is
called intra-polymer bonding.
• Textile fibre polymers are mainly organic compounds, expect some
natural mineral and man-made inorganic fibres.
• They are predominantly composed of carbon and hydrogen atoms,
with some oxygen, nitrogen, chlorine and/or fluorine atoms.
• In general, single covalent bonds join the atoms forming the polymer

52. Intra-polymer Bonds
The major bonds that are used for intermolecular bonding are as
follow
• Covalent bonds
• Amide or peptide group
• Benzene ring
• Ether linkages
• Ester groups
• Hydroxyl group
• Nitrile group

53. Covalent bonds
Covalent bonding is a common type of bonding, in which the
electro negativity difference between the bonded atoms is small
or nonexistent.
Their bond energy or bond strength is between 330 and 420
kilojoules

54. The amide or peptide group:
In chemistry, an amide is an organic compound that contains
the functional group consisting of a carbonyl group (R-C=O)
linked to a nitrogen atom (N).
When present in nylon polymers it is called the amide group.
It is also present in silk, wool, mohair and all other animal or
protein fibres and then it is called peptide group

55. Benzene rings
They are sometimes referred to as the aromatic radical.
 It is a hexagon shaped molecule composed of mainly carbon
and hydrogen

56. Ether linkages
• The ether linkages may be found in polymers such as cellulose,
elastomeric, ester-cellulose and polyesters.
• It exists between carbon and oxygen atoms.
• Ethers are chemically unreactive. One reason for this is the
great chemical stability of the carbon-oxygen linkages found in
every ether molecule.

57. Ester groups
• They are formed by replacing the hydrogen of an acid with an
organic radical.
• In fibre polymers they are usually the reactions between:
a. A carboxyl group (-COOH), also called carboxylic acid
b. A hydroxyl group (-OH)

58. Inter polymer bonds
• In basic senses these bonds are responsible for holding the
polymers together for the formation of a fibre.
• The major bonds used for interpolymer bonding are as follows,
Van der Waals forces
Hydrogen bonds
Salt linkages

59. Van der Waals forces:
They are weak forces which exist in the interpolymer forces of
attraction when the atoms come close to one another.
They are formed between atoms along the length of adjacent
polymers when these are less than 0.3 nm apart but no closer
than about 0.2 nm.
They occur between all fibre polymer system and their bond
energy in 8.4 KJ.

60. Hydrogen bonds
They are formed between hydrogen and oxygen atoms, and
hydrogen and nitrogen atoms on adjacent polymers when these are
less than 0.5 nm apart.
They occur within the natural polymers, regenerated cellulose
polymers, nylon polymers, polyvinyl alcohol, polyester polymers,
protein and secondary cellulose acetate fibres.
Their bond energy is 20.9 KJ
The hydrogen bonds are mainly responsible for the tenacity and the
elastic-plastic nature of the natural, regenerated cellulose, nylon,
PVA and protein fibres

61. Salt linkages
• They are formed between the carboxyl radical on one polymer
and the positively charged amino group on an adjacent
polymer.
• They exist mainly in the protein and nylon fibre polymers.
• Their bond energy is 54.4 KJ.
• They are responsible for the attraction of the water molecules
and they too contribute to the strength of the fibre.
• The presence of salt linkages is necessary for dye absorption