Briefing on Aramid Fibers as reinforcement. Introduction, types, production, properties and applications.

1. a
ARAMID FIBERS
AS
REINFORCEMENT
Presented by:
 M. Zain (16-NTU-1406)
 Zeshan Faisal (17-NTU-1088)
(Batch-2017)
Department of Polymer Engineering,
National Textile University,
Faisalabad.

2. Contents
History
Introduction
Types
Fabrication Process
Reinforcement Types
Properties
Applications
ARAMID FIBERS 2

3. History
o American chemist Stephanie Kwolek invented 1st Para-Aramid Fiber which
was after named as Kevlar.
o Dr. Wilfred Sweeny a Scottish born scientist was responsible for discovering
Meta-Aramid Fiber after named as Nomex.
o In 1960, they were firslty introduced for commercial applications.
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Dr. Wilfred SweenyStephanie Kwolek

4. Introduction
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Amide
Carbonyl and amino group condensate to generate amide monomer.
There are basically two types of polyamides:
Nylon Aramids
 Less than 85% amide linkages.  Atleast 85% amide linkages.
 Have [(CH2)n] chains b/w amide linkages.  Have (aromatic ring) b/w amide linkages.

5. Cont.
o Aramid Fiber (Aromatic Polyamide)
 Composed of aromatic di-carbonyl and
aromatic di-Amine.
 Their condensation produce aramids whose
monomer have carbonyl and di-amine.
 long-chain synthetic polyamide.
 Amide linkages are attached to aromatic rings called poly(pheylene
terepthalamide).
ARAMID FIBERS 5
NH2
NH2

6. Types
Numerous combinations of carbonyl(carboxylic acid) and diamine
can be used to produce different types of aramid fibers.
Commercially produced are
Like:-
 Para-Aramid(Cut Resistant)
o Kevlar
o Twaron
 Meta-Aramid(Fire Retardant)
o Nomex
o Teijin Conex
ARAMID FIBERS 6
These two are
the most common
Types of aramids.

7. ARAMID FIBERS 7
Worldwide production of Aramid Fibers
Fiber Name Basic Polymer Producer Estimated Capacity
(Ton/Yr)
M-Aramid Fiber
Nomex Poly(m-phenylene isopthalamide) DuPont Co. 10,000
Teijin Conex Poly(m-phenylene isopthalamide) Teijin Ltd. 5000
Fenilin Poly(m-phenylene isopthalamide) Russia 1000
P-Aramid Fiber
Kevlar Poly(m-phenylene isopthalamide) Du Pont Co. 20,000
Twaron Poly(m-phenylene isopthalamide) Akzo Nobel 10,000
Aramid Co-Polymer Fibers
Technora Copoly(l,4-phenylene/3,4′- diphenylether
terephthalamide)
Teijin Ltd. 1000
Armos Copoly[p-phenylene/5-amino-2- (p
aminophenyl)benzimidazole terephthalamide]
Russia Unknown
Trevar Aramid Copolymer Hoechst AG Unknown

8. Reinforcement Types
o Usually aramid fibers are reinforced into
polymer matrix in three ways:
a) Continuous
b) Woven (2D or 3D)
c) Chopped
o Matrix is the second major component of
composite material.
o Selection of suitable matrix affect the
properties of final material.
ARAMID FIBERS 8

9. Manufacturing Process
Polymer Formation
o Diamine dissolve in water.
o Acid dissolved in solvent i.e.
Cyclohexanone.
o Mixing two solution causes rapid
polymerization.
Spinning
o Dope Formation
 Nomex: Dissolve in LiCl2.
 Kevlar: Dissolve in H2SO4.
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oExtrusion
Dope then extruded through spinret’s
hole to give filament shape.
o Solidification
 Nomex: Solidifies in hot air.
 Kevlar: Solidifies in water.

10. Properties
ARAMID FIBERS 10
Physical Properties
o Optical
 Colour:
o Mechanical
 Tenacity:
Condition Kevlar Nomex
Dry 18-26.5 4.0-5.3
Wet 17-25 3.0-5.3
Fiber Kevlar Nomex
Colour Yellow/Golden White

11. Cont.
ARAMID FIBERS 11
 Density:
Kevlar Nomex
1.44 (g/cm3) 1.38 (g/cm3)
Fiber Type Density
(g/cm3)
% Elongation Modulus
(MPa)
Tenacity
Kevlar 29 1.43 3.6 70 20-23
Kevlar 49 1.45 2.8 135 20-26
Kevlar 149 1.47 1.5 143 18
Nomex 1.38 22 17 5.8

12. Cont.
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o Stress-Strain Curve

13. Cont.
o Structure
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Kevlar Nomex
Para-Aramid Meta-Aramid

14. Cont.
Thermal Properties
o Melting Point
o Glass Transition Temperature
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Kevlar Nomex
Above 500ºC 350ºC
Note: They not only melt but start to decompose at these temperatures.
Kevlar Nomex
170ºC 120-220ºC

15. Drawbacks
 Quickly absorbs moisture.
 Poor UV resistance.
 Difficult to cut and to grind without special equipment. (e.g. special scissors for
cutting)
 Poor compressive properties.
ARAMID FIBERS 15

16. Applications
Buildings
 Fire proofing walls due to its flame-retardancy.
 Insulation of electrical wires.
Protective Textiles
 Uncutable gloves.
 Helmets.
 Bullet-proof wests.
 Astronauts suits.
Sports
 Rackets.
 Tyres.
 Boats.
 Bicycles.
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17. ARAMID FIBERS 17
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