Kevlar body armor

Kevlar body armor works by catching a bullet in a multilayer web of woven fabrics. Kevlar s extraordinary strength resists tearing and cutting, allowing the stressed fibers to absorb and disperse the impact to other fibers in the fabric. 

The most widely used style of Kevlar Body Armor is the conceal able police vest. This type of armor may be either a single front pad or both front and rear panels. Other styles commercially available include a T-Shirt with integral pad (see Part II),quilted ski-type jackets, military flak jackets and even Kevlar lined suits and raincoats for politicians and executives. 

Flexible Kevlar body armor, even with dual pads and metal inserts, will not stop some high power rifle bullets. The three most difficult rounds to stop are tungsten cored 308 NATO and 223 NATO AP and the 7.52 Soviet AP Incendiary. 

VEST-BUSTERS How to Make Your Own Body-Armor-Piercing Bullets, by Uncle Fester. What do you do when you re attacked by armed invaders who are wearing Kevlar body armor If you followed this book s clear, concise instructions, you re ready to drop them in their tracks Don t be a victim... be a victor instead Give yourself the winning edge, and learn how to make your own body-armor-piercing bullets Sold for informational purposes only. 1996, 5Vi X 8V2, 72 pp, soft cover. 12.00. 

A while bade, NBC Magazine abowed the 357 Magnum Teflon coated bullets which would go through three folds of Kevlar body armor. Such bullets cost ab 135.00 per box of 50. 

Nor would such bullets be useful against foreign invaders or local marauders. Kevlar body armor is too expensive to be suigdied to communist regular infantry and if marauders had the foresight to buy sudi armor, why wouldn t they stodc ig) on food so they wouldn t have to maraud in the first place ... 

CAUTION Sodium nitrotetrazolate dihydrate is an energetic material with sensitivity to various stimuli. Particular care should be taken to not excessively dry the material, as anhydrous NaNT is considerably more sensitive than the dihydrate. While we encountered no issues in the handling of this material, proper protective measures (face shield, ear protection, body armor, Kevlar gloves, and earthened equipment) should be used at all times. 

Kevlar a polymer fiber that is stronger than steel, but very light. It is used to make bullet-proof vests and other body armor. 

Kevlar, a polymer, is a special kind of fiber that is five times stronger than steel, and it is used to make body armor and sports equipment. 

In the future, body armor may be flexible. Experimentation is underway with shear thickening material using polyethylene glycol (PEG) with nanoparticles that remain flexible until rapidly struck such as with a bullet whereupon it acts as a solid protecting the wearer from the major impact. Kevlar is also being employed to protect space craft and space men from discarded space junk and small meteors. Thus, experimentation in body armor is being applied to additional areas where impact protection is essential. 

The rigid, rod-shaped molecules of Kevlar are very crystalline and can be used to form strong, stiff, high-strength fibers. Although this polymer is fairly expensive, it is used in high-tech applications such as bulletproof body armor. 

Kevlar 29 and versions thereof (K 129 and Kl j.) are also used extensively in lightweight body armor as well as composite liners (with vinylester, polyester or epoxy as the matrix). A quick look at the properties of different Kevlar aramid fibers in Table 4.2 shows why K29 is better than K49 for lightweight body armor applications. K29 has a higher strain to failure than K49. That means that the total work of fracture, i.e. the area under the stress-strain curve, is larger for K29 than K49. Hence, the energy absorbed in the fracture process is higher for K29... 

Two types of cloth are used. The first is "S" type fiberglass, superior to "E" type cloth sold to the public. The second is Kevlar 49, the same a ramid fiber fabric used in Second Chance Flexible Body Armor. Both types of cloth are treated or scoured to make the surface compatible with a variety of laminating resins, including vinylester, polyester and epoxy. 

The body armor described here is constructed of DuPont Kevlar Fabric. This cloth is woven from strands of Kevlar Aramid Fiber, a material developed by DuPont as a replacement for steel wire belted radial tires.This material is lighter than ballistic nylon and pound for pound it s several times as strong as steel. When Kevlar is used in multiple layers, it can effectively stop bullet penetration and greatly reduce internal injuries from blunt trauma. Finished armor pads are light, flexible and easily concealed. 

A. General Info The flexible armor pad insert is made from 8 layers of DuPont Kevlar Aramid Fabric.Two types of Kevlar cloth are appropriate for use in soft body armor. 

B. Technical Info An excellent source of Kevlar technical information is a 1976 Government sponsored report on Lightweight Body Armor. The 113 page report contains many charts and illustrations. 

It is interesting to note that body armor design has come full circle. Compare current Kevlar/metal plate armor with its 19th Century felt and metal counterpart.(See "The Same Thing Over Again" - 1894 reprinted in PMA Vol.1 page 13.)... 

Some body armor is available from civilian markets (i.e., Kevlar chain saw leggings). Kevlar helmets, flak vests (not the old ballistic nylon ones, but Kevlar), and groin aprons are available at Army surplus stores in states where they are not illegal. Kevlar gloves, not included in the above list because they were not available at the time this list was developed, are now available from safety supply houses and should be used. They can be lined with Nomex gloves for further protection from fire. Summer Nomex flying gloves are also available at surplus stores and provide the flexibility necessary for fine dexterity. 

Police and the military depend on body armor and helmets made of Kevlar fibers. Kevlar protective equipment is more effective than steel, yet far lighter in weight. 

Initially, Kevlar was used in car tires as reinforcement for the elastomeric matrix (rubber) however, nowadays the most widely known appHcation of Kevlar/epoxy is in body armor [27]. Other uses include fireproof suits for firefighters, gloves, and helmets [28]. Their high strength-to-weight ratio makes them more suitable for use as reinforcement, for example, in composite materials primarily where flexure properties are important, such as aircraft wings [29]. 

Kevlar is five times the strenglii of steel on an equal-weight basis, it is used in ballistic and stab-protective body armor. 

Spider-web silk is ca. five times stronger than steel by weight, and almost as elastic as nylon. Fibers comprised of the synthetic silk were demonstrated to be stronger than Kevlar, and may be useful for biomedical applications such as artificial tendons and ligaments and surgery sutures, as well as lightweight body armor for military applications. 

KEVLAR DuPont Kevlar aramid fibers are lightweight and extraordinarily strong, with five times the strength of steel on an equal-weight basis. Best known for its use in ballistic and stab-resistant body armor, Kevlar brand aramid fibers are also used in cut-resistant and heat-resistant protective gloves and sleeves. Woven and knit gloves made solely from Kevlar fibers do not provide chemical protection. 

Numerous security devices may reduce the risk for assaults against workers and facilitate the identification and apprehension of perpetrators. These include closed-circuit cameras, alarms, two-way mirrors, card-key access systems, panic-bar doors locked from the outside only, and trouble lights or geographic locating devices in taxicabs and other mobile workplaces. Personal protective equipment such as body armor has been used effectively by public safety personnel to mitigate the effects of workplace violence. For example, the lives of more than 1800 police officers have been saved by Kevlar vests. 

The sturdiness of the amide linkage is amply demonstrated by the properties of poly(p-phenylene terephthalamide), which is used in bulletproof vests and body armor under the commercial name of Kevlar. Developed by DuPont chemist Stephanie Kwolek, Kevlar is 16 times as stiff as nylon, the polymer formerly used in such applications. Kevlar s properties derive from the planarity of its benzene rings combined with restricted rotation about the amide linkages (Section 20-6). Thousands of law enforcement officers owe their lives to this remarkable material, which can stop the bullet from a 9-mm handgun traveling at 1200 feet per second. 

When the diamine and the dicarboxylic acid are attached to aromatic rings, the generic term for the polymers produced is aramide. The reaction of 1,4-diaminobenzene with tere-phthaloyl chloride gives poly(para-phenylene terephthalamide) (PPTA) marketed as Kevlar (Figure 21.23). Because of the extensive hydrogen bonding network between the chains (Figure 21.24), this is an extremely stiff material and has found wide applications in body armor and safety equipment. 

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