Ballistic materials used to make a bullet proof vest

A bullet proof vest is not "just” a bullet proof vest. Ballistic body armor is made in different parts of the world and there are a variety of ballistic materials that can be used to build the ballistic property in a bullet proof vest.

In this guide we deal with the difference between an Aramid and UHMWPE, where we will review the most well-known and used ballistic materials today.

Depending on the materials used in a bullet proof vest, this will affect the flexibility, thickness, weight and what types of shots the bullet proof vest can stop. Therefore, it may feel like searching for a needle in a haystack when looking for a bullet proof vest, as it can be difficult to figure out what’s what and what is best.

However, all bullet proof vests have one thing in common which is that they should be able to stop the same type of cartridge, whether made to the:

• American NIJ (National Institute of Justice: 0101.04 and 0101.06 with Levels IIA, II and IIIA)
• German Standard (German Schutzklasse Standard Edition 2008, Level SK1-SK2)
• British Standard (HOSDB Standard, Level HG1 / A, HG1 and HG2).

The above standards are all for soft body armor.

Before we begin to tell about the different bullet proof materials, you must understand the difference between these. There are 2 main materials for body armor.
 

UHMWPE

The first material is UHMWPE which is an ultra-high-molecular-weight polyethylene, which is a chemical polymerization process in which monomers are converted to polymers. UHMWPE is VERY strong versus its weight, and has a high resistance to both ballistic, sharp edged and pointed instruments. UHMWPE is not only used in bullet proof and stab proof vests, but also in clothing, fishing lines, cut resistant gloves, aircraft containers, sports equipment, clothes, etc.

Main Properties of UHMWPE:

• High wear resistance.
• A Low weight material with an incredible strength.
• Do not lose its strength when being exposure to UV light.
• High performance against liquid chemicals.
• Does not lose its ballistic characteristic and has no internal friction.

UHMWPE is made by many different manufacturers, where the best known is Endumax from Teijin, Dyneema from DSM and Spectra Shield, Gold Shield and Gold Flex from Honeywell. In addition to these, there are many less well-known brands, which also manufacture UHWMPE for bullet proof vests.

Dyneema from DSM

Dyneema is one of the most used polyethylene materials in bullet proof vests and according to DSM itself, Dyneema is up to 15 times stronger than steel, and 40% stronger than aramid fibers when considering the weight versus the strength. DSM has many different Dyneema fibers, which all have different properties.

• Dyneema Force Multiplier Technology is used for Bullet- and stab proof vests (Multi vests)
• For ballistic plates, helmets and shields, Dyneema HB212, HB210, HB80, HB56, HB50, HB26 and HB2 are used.
• For Body armor, SB117, SB115, SB71, SB51, SB34, SB31, SB28 and SB21 are used.

As you can see, there are many different materials to choose from, which also mean that a bullet proof vest manufactured in Dyneema is not the same, as it can have different flexibility, weight and thickness. Many body armor manufacturers blend Dyneema with aramid fibers to achieve the best ballistic protection.

For example, Protection Group Danmark has manufactured a low weight ballistic vest with Dyneema SB71, with a weight of only 4.5 kilos per square meter. This results in a bullet proof vest in with a weight of only 1.24 kilos for the ballistic inserts alone (size large). However, the Dyneema SB71 is very rigid, and far from as flexible as other types of Dyneema such as the SB115, which is the lightest and most flexible Dyneema (also extremely expensive).

This also means that Dyneema is often mixed with aramids to get a flexible and light weight bullet proof vest.

An example of this is Honeywell with their Gold Flex and Gold Shield fiber, made from Honeywell's own UHMWPE fiber, and Kevlar. This bullet proof vest is made of both aramid and UHMWPE, which benefits from the unique properties of both materials, providing a flexible, lightweight and strong bullet proof vest made of aramid and UHMWPE.

You can read more about our bullet proof vest here.

Aramid

Aramid is a synthetic fiber that was created back in the 1960s by Stephanie Kwolek. The fiber is known especially from Dupont Kevlar, which were the first company with a commercial version for bullet proof vests, followed by Twaron from Teijin. Aramid is used in bullet proof vests and stab proof vests, as the material is very strong and flexible, and has proven to be stable and safe after many years of use.

The main characteristics of Aramid:

• High strength.
• Provides good resistance to chemical chemicals.
• No conductivity.
• No melting point.
• Good against hot and cutting elements.
• Sensitive to UV and acids.

For bullet proof vests, there are 2 different types of aramids. UD (unidirectional aramid) and woven aramid.

Unidirectional aramid consists of 2-4 layers of aramid fiber plied in a 0°/90° configuration or a 0°/90°/0°/90° configuration. UD aramid is typically a bit more rigid than woven aramid; however, this material has the advantage that it is strong and has a low weight.

Woven aramids are aramids that are woven together in a more traditional manner. Here, there are many different weaving methods that affect the strength and overall weight of the material. Woven aramid is often very flexible and can stop contact shots from a distance of 0 meters.

UD and Woven aramid are made from Kevlar thread from Dupont, Twaron aramid from Teijin or Artec from Pro-Systems S.p.A.

Woven aramid is often much more flexible than UD aramid, and can bend in several directions where UD aramid is more rigid. (There are, of course, different qualities, and therefore the flexibility of UD aramid can be different, for example the UD42 from Teijin which is an extremely flexible aramid UD that immediately shapes to the body of the user.)

It's important to understand that you can both buy the finished bulletproof material at Teijin and Kevlar, or choose to buy their thread, and then develop their very own UD aramid or woven aramid with their thread.

At Protection Group Denmark, we have made use of UD aramid from Teijin, which provides one of the market's thinnest and most flexible aramid bullet proof vests, with a weight of 5.5 kilos per square meter (1.5 kilograms for a size Large) with a thickness of only 6 mm. The UD aramid is very flexible and perfect for concealable body armor solutions.

You can read more about bullet proof vest here.

Kevlar Aramid from Dupont

Kevlar is the most famous and used aramid in the world. The common person has heard the word “Kevlar”, and it is often thought that it relates to bullet proof products. However, the fiber is also used for aircrafts, ships, car parts (tires), engine parts, different industries where you wear cut resistant gloves/shirts, fire proof clothing, brakes, etc.

Kevlar is generally more flexible than UHMWPE, and comes in many different qualities. This is also because many manufacturers buy the fiber and weave their own solution, which results in a wide range of qualities, as you can buy Chinese Kevlar spun body armor and European spun body armor.

Kevlar XP is one of Dupont's leading solutions, and according to Dupont this solution provides up to 15% less back face deformation and the total solution will have at least 10% less weight compared to similar aramid solutions. Twaron from Teijin reminds a lot of Kevlar, as Teijin also offer thread and self-developed solutions.

Teijin as developed the Twaron LFT-AT / AT flex liner, which is a BFS solution that adds 1-2 layers AT flex that gives up to 40% less back face deformation. For example, this aramid can be used with Dyneema, Kevlar or Spectra to achieve a thin and flexible solution with a low Back face signature.