kevlar and its applications
Post on 02-May-2017
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PROJECT REPORT ONKEVLAR AND ITS APPLICATIONS
Presented By:
Himank Joshi(51) ECE Branch
What is Kevlar?
Kevlar is a material formed by combining para-phenylenediamine and terephthaloyl chloride.
Aromatic polyamide (aramid) threads are the result. They are further refined, by dissolving the threads and spinning them into regular fibres.
When woven, Kevlar forms a strong and flexible material.
If layers of the woven Kevlar® are combined with layers of resin, the resulting ‘rigid’ material is light and has twenty times the strength of steel.
Development 1964- Stephanie Kwolek and her colleagues at
DuPont began searching for a new lightweight strong fiber for light, strong tires
1965- discovery of new method of producing polymer chains
1971- high strength Kevlar(poly-paraphenylene terephthalamide) introduced by DuPont
Structure The molecular structure includes a Benzene ring which allowed formation of structures on the ring Alignment of the chains allows Kevlar to be integrated into composite materials The molecules layer themselves in such a way that in order to break through Kevlar, the molecular bonds have to be broken
Properties High modulus High tensile strength at low weight Low electrical conductivity High chemical resistance Low thermal shrinkage High toughness High cut resistance Flame resistant/self extinguishing Immune to electron radiation
UV Light- the only breaking material
Causes discoloration and degradation of the Kevlar in the presence of oxygen
Not influenced by moisture or atmospheric contaminants Damaging if the wave is absorbed by the polymer SOLUTION: It’s coated with something UV resistant
(absorbant)
Applications in Military Vehicle Armor
Spall Liners Also protects aircraft and helicopter crews
Military Helmets Absorb 20% more kinetic energy for Ground Troops Improve mobility and fatigue of GIs because of low weight
Body Armor Improved Outer Tactical Vest, ballistic inserts, throat and groin
protectors, anti-mine boots and chaps
GENERAL APPLICATIONS•Ropes and cables•Auto hoses and belts•Composite materials•Tires•Fiber optic cables•Sporting goods •Umbilical hoses on offshore oil and gas refineries•Insulation
Transportation
Aircraft
Maritime vessels
Space Applications In the Mars Pathfinder to
reinforce the inflatable landing cushions and securing ropes
> survived 40 million mile journey
Space shuttle and communications satellites to protect against impacts from orbital debris Hubble Telescope!
Space Station
Used in modules of the International Space Station (ISS) to protect from micrometeorites and orbital debris
Helps protect crew from radiation
Basic layout of module wall: 1. metal, 2. Kevlar, 3. main structure (pressure shell),4. thermal insulation
Why use Kevlar to protect the ISS?
Lightweight Low thermal expansion Resilient Woven fibers are strong and flexible
Flexibility absorbs shock from impacts
Everyday Kevlar
Fire Resistant Mattresses Personal Electronics Sports
Boarding/Skiing Baseball Hiking
THANK YOU
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