E-Book - Kevlar Bulletproof Vest

Kevlar®
Bulletproof
Vest

Group 2

Group Members

Name Matric No.
Nur Ainie Binti Abdul Kamal D20191089933
Ahmad Ainul Safwan Bin Sazali D20191089944
Mohamad Shahfinaz Bin Ramli D20191089947
Aqielah Binti Azizan D20191089956
D20191089957
Zielkindeeory Zerlin

Table of contents

01 Introduction 02 History

03 How It’s Work 04 The Good and The Bad

05 Kevlar® vs Carbon Fiber

01

Introduction

Explaining body armor and
Kevlar® in general

Body Armor Vest

Body armor items Mostly worn by Prison guards Soldiers, SWAT
that help absorb many police and police can teams, marines and
impact and reduce officers, prison wear soft jackets special operations
or stop penetration guards, security designed to teams wear hard
into the body from guards and withstand stab armor, either along
bullets fired from some private attacks, using with soft armor or
firearms and debris citizens. metal or alone. This allows
from explosions. para-aramid protection against
components. rifle bullets or
debris.

Kevlar®

Kevlar®

i. ii. iii.

Kevlar® (para-aramid) is a High-strength materials It is usually twisted into a
heat-resistant and strong
synthetic fiber, related to were first used rope or sheet of cloth
other aramids such as
Nomex and Technora. commercially in the early that can be used as such,
Developed by Stephanie
Kwolek at DuPont in 1965. 1970s as a substitute for or as an ingredient in

steel in racing tires. composite material

components.

Kevlar® has many applications, all due to its high strength-to-weight ratio, by this
measure it is five times stronger than steel.

Other
applications

Bicycle Tires Racing Sails Gloves

Kevlar® K100 Kevlar® K129

Colored version of Higher durability for
Kevlar ballistic applications

Kevlar® K119 Types of Kevlar® AP
Kevlar®
Features higher elongation Has a tensile strength
as well as more flexible and of 15% higher than
more fatigue resistance K-29

Kevlar® Manufactured Location

Richmond, USA These three sites have a production
capacity of 65.9 million pounds of the
Northern 94.7 million pounds of total aramid
Island fibers capacity.

Japan

02 History

The History of Body Armor,
From Medieval Times to Today

Early Modern Era 1885

The invention of true “body armor” directly Victorian Era
followed the development of ranged
weapons. Muskets became widely used in Criminals fashioning their own
the 16th Century. The only materials protective gear (Ned Kelly).
available to early ballistics engineers is Impenetrability of silk to bullets
metal plate. It were used a lot by medival made by Dr. George Goodfellow
knights Archduke Franz Ferdinand, the heir
to the throne of Austria-Hungary,
1815 owned a silk vest that would have
stopped a bullet.

The Revolution

A research chemist, Stephanie Kwolek

came up material that is known as Kevlar.
Its five times the tensile strength of steel. A
Kevlar®vest, the K-15. It used 15 layers of
Kevlar

2020-

1965

Today

Bullet proof to stop 9mm rounds, 7.62mm
rounds at range, and most shrapnel. It’s five
times the tensile strength of steel recent
forms of body armor provide less protection
than those of the 1970s.

How It’s

Work 03

1 When a bullet hits a Kevlar® vest, it gets caught
in the web of strong fibers like Kinetic Energy.

HOW 2 Which absorbs and dissipates the energy,
KEVLAR® drastically reducing the impact of the bullet.
VEST 3
WORK? The fibers are lined up so tightly that takes
a great deal of energy to separate them.

The more layers of Kevlar® sheets, the
greater the absorption.

Depending on the grade of Kevlar®
used and the number of layers.

The vest is strong enough to cause the
bullets that hit it to become distorted
or bent.

What makes Kevlar® such a good
antiballistic material?

The tightly woven fibers

It takes a great deal of of highly oriented
energy to make a
bullet pass throught (lined-up) polymer
it.
molecules are

esxtremely hard to

move apart.

Polymides like Kevlar The chains are
are polymers that is
huge molecules made cross-linked with
of many identical
parts joined together hydrogen bonds, which
in long chains
gives the material its

super high-tensile

strength.

04

The Good
and
The Bad

The Good Side of Kevlar®

Fire Retardant High Strength

Kevlar is similar in structure Comes with different grade
strengths such as 29, 49 and
to Nylon but differs from the 149. This enables the fabric
to protect the wearer from
same on account of bullets or other forms of
projectiles (armed forces
containing closely packed used)

polymer chains, which in

turn makes Kevlar one of the

most resilient fabrics

synthesized. (most

firefighters used)

The Bad Side Quite Stiff
of Kevlar®
It is this stiffness, which makes
it a little inefficient as it can
restrict free movement. Which
is why at the moment, it is only
used as an external gear.

Sensitive to The
Surrounding

Most of Kevlar used in
protective gear comes with a
waterproof padding, so as to
prevent the Kevlar from being
damaged, due to excessive
moisture.

Kevlar®

05 vs

Carbon Fiber

Carbon Fibre

It’s most highly known to be top choice in
aerospace and industrial applications due to its
high tensile strength, low density, high
rigidity, and thermal conductivity. In fact,
Carbon Fibers yield the highest material
strengths across the board when compared to
Kevlar. It exceeds comparable fibers in
strength to weight and stiffness categorizes.
For this reason, it replaces alloys in aerospace
components that formerly used aluminum or
titanium. Carbon Fiber composites excel at
keeping dimensional tolerances as loading is
applied.

Difference Between Kevlar® and

Carbon Fibre

Carbon Fibre Kevlar®

Chemical Structure Contains nitrogen atoms Mainly contains carbon
atoms

Bonds Hydrogens bonds Via carbon atoms

Heat Resistant Not as high Kevlar® High heat resistant

Flexibility Flexible Very rigid and stiff

Weight Much heavier Lightweight

Conclusion,

While carbon fibre offers the best strength and rigidity to weight in
the industry; it is also generally the most expensive of
reinforcements. That said, Kevlar® offers a better abrasive strength
than carbon fibre, which is why it commonly associated with
bulletproof vests.