what is a bulletproof vest made out of
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What is a bulletproof vest made out of absa forex exchange rates

What is a bulletproof vest made out of

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The vest was a success, worn by dignitaries and royalty. Roughly 12 years before Princip pulled the trigger and killed Ferdinand, the bulletproof vest made by Zeglen and Szczepanik saved the life of the King of Spain, Alfonso XIII, during an assassination attempt. And throughout World War I, industrialists courted the favor of the Polish duo, hoping they might help propel the German and Austro-Hungary advances to victory.

Civil, foreign and World Wars were fought in a period when even the toughest armor could not stop the most lethal weapon. At the turn of the century, it is observed that protective gear was greatly scaled back, retreating once more from full-body armor to strategically placed metal plates. As battlefields grew farther apart and cannon fire spelled imminent death, and as the fighting grew less personal and more distanced like the relationship between the men who called the orders to those who marched to them , men wore metal plates over their uniforms and donned metal helmets to protect against gunfire.

These plates were placed over the heart, which often beat with a fear that was hardly aided by the presence of a thin metal sheet and, later, a tightly-woven polymer simply known as Kevlar. Kevlar, or light and ultra-strong plastic polymers that are tightly woven into a flexible fabric, became popular after its discovery and implementation in the s. It is now used in everything from sporting equipment—tennis rackets, Formula 1 cars, boating sails—to personal protective equipment like bulletproof vests.

Despite all the advances in chemical compounds that form some of the strongest materials on Earth, and which are often used to mitigate the damage wrought by firearms or natural disasters, the science that has gone into the fireproofing and weaponization of simple polymers has more recently returned to its Arizona roots. Two years ago, researchers at the Air Force Research Laboratory announced that they would be looking into an age-old fiber to more fully explore its cooling and temperature regulation properties, and its use toward strengthening current synthetic fibers.

That fiber was silk. Artificial spider silk, the researchers suggested, could make for a lighter, stronger and more breathable body armor than even Kevlar. Kenneth R. Rosen is the author of the forthcoming Bulletproof Vest. For more information, go to www. Each classification specifies which type of bullet at what velocity will not penetrate the vest. While it seems logical to choose the highest-rated vests such as III or IV , such vests are heavy, and the needs of a person wearing one might deem a lighter vest more appropriate.

For police use, a general rule suggested by experts is to purchase a vest that protects against the type of firearm the officer normally carries. The size label on a vest is very important. Not only does it include size, model, style, manufacturer's logo, and care instructions as regular clothing does, it must also include the protection rating, lot number, date of issue, an indication of which side should face out, a serial number, a note indicating it meets NIJ approval standards, and—for type I through type III-A vests—a large warning that the vest will not protect the wearer from sharp instruments or rifle fire.

Bulletproof vests are tested both wet and dry. This is done because the fibers used to make a vest perform differently when wet. Testing wet or dry a vest entails wrapping it around a modeling clay dummy. A firearm of the correct type with a bullet of the correct type is then shot at a velocity suitable for the classification of the vest. Each shot should be three inches 7. Six shots are fired, two at a degree angle of incidence, and four at a 0-degree angle of incidence.

One shot should fall on a seam. This method of shooting forms a wide triangle of bullet holes. The vest is then turned upside down and shot the same way, this time making a narrow triangle of bullet holes. To pass the test, the vest should show no sign of penetration. That is, the clay dummy should have no holes or pieces of vest or bullet in it. Though the bullet will leave a dent, it should be no deeper than 1. When a vest passes inspections, the model number is certified and the manufacturer can then make exact duplicates of the vest.

After the vest has been tested, it is placed in an archive so that in the future vests with the same model number can be easily checked against the prototype. Rigged field testing is not feasible for bullet-proof vests, but in a sense, wearers such as police officers test them everyday.

Studies of wounded police officers have shown that bulletproof vests save hundreds of lives each year. Tarassuk, Leonid and Claude Blair, eds. The Complete Encyclopedia of Arms and Weapons. Simon and Schuster, Anderson, Jack and Dale Van Atta. April 9, , p. Chapnick, Howard. November , pp. Faison, Seth, Jr. September 15, , p. Flanagan, William G. July 6, , p. Lappen, Alyssa A. February 6, , pp. Toggle navigation. Kevlar has long been the most widely used material in bulletproof vests. To make Kevlar, the polymer solution is first produced.

The resulting liquid is then extruded from a spinneret, cooled with water, stretched on rollers, and wound into cloth. A recent competitor to Kevlar is Spectra Shield. Unlike Kevlar, Spectra Shield is not woven but rather spun into fibers that are then laid parallel to each other. The fibers are coated with resin and layered to form the cloth. After the cloth is made, it must be cut into the proper pattern pieces. These pieces are then sewn together with accessories such as straps to form the finished vest.

Other articles you might like:. User Contributions: 1. I would like to know if someone knows about this type of project. I can design but I would like to know better the materials that I have to use when I make the vest. An were I can buy it or find it what store. Thank you in advance. Violeta McClellan. Comment about this article, ask questions, or add new information about this topic: Name:.

E-mail: Show my email publicly.

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These newer materials are advertised as being lighter, thinner and more resistant than Kevlar, although they are much more expensive. The US military has developed body armor for the working dogs who aid GIs in battle. Since , U. Special Operations Command has been at work on a new full-body armor that will rely on rheology , or the technology behind the elasticity of liquids in skin care and automotive products.

Due to the various types of projectile, it is often inaccurate to refer to a particular product as " bulletproof " because this implies that it will protect against any and all threats. Instead, the term bullet resistant is generally preferred.

Body armor standards are regional. Around the world ammunition varies and as a result the armor testing must reflect the threats found locally. Law enforcement statistics show that many shootings where officers are injured or killed involve the officer's own weapon. While many standards exist, a few standards are widely used as models. The US National Institute of Justice ballistic and stab documents are examples of broadly accepted standards.

These "model" standards are usually adapted by other counties by incorporation of the basic test methodologies with modification of the bullets that are required for test. NIJ Standard This rates vests on the following scale against penetration and also blunt trauma protection deformation : [19]. NIJ standards are used for law enforcement armors. Each armor program can select a unique series of projectiles and velocities as required. In addition, special requirements can be defined under this process for armors for flexible rifle protection, fragment protection for the extremities, etc.

Textile armor is tested for both penetration resistance by bullets and for the impact energy transmitted to the wearer. The "backface signature," or transmitted impact energy, is measured by shooting armor mounted in front of a backing material, typically oil-based modeling clay.

The clay is used at a controlled temperature and verified for impact flow before testing. After the armor is impacted with the test bullet, the vest is removed from the clay and the depth of the indentation in the clay is measured. The backface signature allowed by different test standards can be difficult to compare.

Both the clay materials and the bullets used for the test are not common. In general the British, German and other European standards allow 20—25 mm of backface signature, while the US-NIJ standards allow for 44 mm, which can potentially cause internal injury. In general a vest's textile material temporarily degrades when wet. Neutral water at room temp does not affect para-aramid or UHMWPE but acidic, basic and some other solutions can permanently reduce para-aramid fiber tensile strength.

Vests that will be tested after ISO type water immersion tend to have heat sealed enclosures and those that are tested under NIJ type water spray methods tend to have water resistant enclosures. This concluded that water, long-term use, and temperature exposure significantly affect tensile strength and the ballistic performance of PBO or Zylon fiber.

This NIJ study on vests returned from the field demonstrated that environmental effects on Zylon resulted in ballistic failures under standard test conditions. Because the energy of a bullet is a key factor in its penetrating capacity, velocity is used as the primary independent variable in ballistic testing. For most users the key measurement is the velocity at which no bullets will penetrate the armor.

Measuring this zero penetration velocity v 0 must take into account variability in armor performance and test variability. Ballistic testing has a number of sources of variability: the armor, test backing materials, bullet, casing, powder, primer and the gun barrel, to name a few. Variability reduces the predictive power of a determination of V0. The problem is variability. If the v 0 is tested again with a second group of 30 shots on the same vest design, the result will not be identical.

Only a single low velocity penetrating shot is required to reduce the v 0 value. The more shots made the lower the v 0 will go. In terms of statistics, the zero penetration velocity is the tail end of the distribution curve. If the variability is known and the standard deviation can be calculated, one can rigorously set the V0 at a confidence interval.

Test Standards now define how many shots must be used to estimate a v 0 for the armor certification. This procedure defines a confidence interval of an estimate of v 0. This is the velocity at which 50 percent of the shots go through and 50 percent are stopped by the armor. The goal is to get three shots that penetrate that are slower than a second faster group of three shots that are stopped by the armor.

These three high stops and three low penetrations can then be used to calculate a v 50 velocity. In practice this measurement of v 50 requires 1—2 vest panels and 10—20 shots. A very useful concept in armor testing is the offset velocity between the v 0 and v If this offset has been measured for an armor design, then v 50 data can be used to measure and estimate changes in v 0. For vest manufacturing, field evaluation and life testing both v 0 and v 50 are used. However, as a result of the simplicity of making v 50 measurements, this method is more important for control of armor after certification.

After WWII, vests were being developed and fragment testing was in its early stages. They all contain a steel casing that is designed to burst into small steel fragments or shrapnel, when their explosive core detonates. After considerable effort measuring fragment size distribution from various NATO and Soviet bloc munitions, a fragment test was developed.

This shape has a length equal to its diameter. The test series most often includes 2 grain 0. The series is based on the measured fragment size distributions. German Policemen in bulletproof vests on guard duty at a military hospital.

The military engineering data showed that, like the fragment size, the fragment velocities had characteristic distributions. It is possible to segment the fragment output from a warhead into velocity groups. This established a set of goals for military ballistic vest design.

The random nature of fragmentation required the military vest specification to trade off mass vs. Hard vehicle armor is capable of stopping all fragments, but military personnel can only carry a limited amount of gear and equipment, so the weight of the vest is a limiting factor in vest fragment protection. The grain series at limited velocity can be stopped by an all-textile vest of approximately 5.

In contrast to the design of vest for deformable lead bullets, fragments do not change shape; they are steel and can not be deformed by textile materials. The 2-grain 0. As a result fabrics optimized for fragment protection are tightly woven, although these fabrics are not as effective at stopping lead bullets.

One of the critical requirements in soft ballistic testing is measurement of "back side signature" i. The selection of test backing is significant because in flexible armor, the body tissue of a wearer plays an integral part in absorbing the high energy impact of ballistic and stab events.

However the human torso has a very complex mechanical behavior. Away from the rib cage and spine, the soft tissue behavior is soft and compliant. This complexity requires very elaborate bio-morphic backing material systems for accurate ballistic and stab armor testing. In all cases, these materials are placed behind the armor during test impacts and are designed to simulate various aspects of human tissue impact behavior.

One important factor in test backing for armor is its hardness. Armor is more easily penetrated in testing when backed by harder materials, and therefore harder materials, such as Roma clay, represent more conservative test methods. Stab and spike armor standards have been developed using 3 different backing materials. This history helps explain an important factor in Ballistics and Stab armor testing, backing stiffness affects armor penetration resistance.

When the force is reduced by a softer more compliant backing the armor is less likely to be penetrated. The use of harder Roma materials in the ISO draft norm makes this the most rigorous of the stab standards in use today. Because of the limitations of the technology a distinction is made between handgun protection and rifle protection. See NIJ levels 3 and 4 for typical requirements for rifle resistant armor.

Broadly rifle resistant armor is of two basic types: ceramic plate -based systems and hard fiber-based laminate systems. Many rifle armor components contain both hard ceramic components and laminated textile materials used together. Various ceramic materials types are in use, however: aluminum oxide, boron carbide and silicon carbide are the most common.

However, for rifle protection high pressure lamination of ultra high molecular weight polyethylene with a Kraton matrix is the most common. The weight and stiffness of rifle armor is a major technical challenge. The density, hardness and impact toughness are among the materials properties that are balanced to design these systems. While ceramic materials have some outstanding properties for ballistics they have poor fracture toughness. Failure of ceramic plates by cracking must also be controlled.

The strike face is ceramic with the backface formed of laminated fiber and resin materials. The hardness of the ceramic prevents the penetration of the bullet while the tensile strength of the fiber backing helps prevent tensile failure. Examples of rifle resistant outer vests include the Interceptor body armor and the Improved Outer Tactical Vest. The standards for armor-piercing rifle bullets aren't clear-cut, because the penetration of a bullet depends on the hardness of the target armor.

However there are a few general rules. For example, bullets with a soft lead-core and copper jacket are too easily deformed to penetrate hard materials, whereas rifle bullets manufactured with very hard core materials, like tungsten carbide , are designed for maximum penetration into hard armor.

Many common bullets, such as the 7. Additionally, as the hardness of the bullet core increases, so must the amount of ceramic plating used to stop penetration. Like in soft ballistics, a minimum ceramic material hardness of the bullet core is required to damage their respective hard core materials, however in armor-piercing rounds the bullet core is eroded rather than deformed.

The US Department of Defense uses two classes of protection from armor-piercing rifle bullets. Bomb disposal officers often wear heavy armor designed to protect against most effects of a moderate sized explosion, such as bombs encountered in terror threats. Full head helmet, covering the face and some degree of protection for limbs is mandatory in addition to very strong armor for the torso. An insert to protect the spine is usually applied to the back, in case an explosion blasts the wearer.

Visibility and mobility of the wearer is severely limited, as is the time that can be spent working on the device. Armor designed primarily to counter explosives is often somewhat less effective against bullets than armor designed for that purpose. The sheer mass of most bomb disposal armor usually provides some protection, and bullet-specific trauma plates are compatible with some bomb disposal suits. Bomb disposal technicians try to accomplish their task if possible using remote methods e.

Actually laying hands on a bomb is only done in an extremely life-threatening situation, where the hazards to people and critical structures cannot be lessened by using wheeled robots or other techniques. In the mids the state of California Department of Corrections issued a requirement for a body armor using a commercial ice pick as the test penetrator. The test method attempted to simulate the capacity of a human attacker to deliver impact energy with their upper body.

As was later shown by the work of the former British PSDB, this test over stated the capacity of human attackers. The test used a drop mass or sabot that carried the ice pick. Using gravitational force, the height of the drop mass above the vest was proportional to the impact energy. The ice pick has a 4 mm 0.

The California standard did not include knife or cutting edge weapons in the test protocol. In this early phase only titanium and steel plate offerings were successful in addressing this requirement. Point Blank developed the first ice pick certified offerings for CA Department of Corrections in shaped titanium sheet metal.

Vests of this type are still in service in US corrections facilities as of The transition from hard, dense clay-based Roma to soft low-density gelatin allowed all textile solutions to meet this attack energy requirement. It is important for users to understand that the smooth, round tip of the ice pick does not cut fiber on impact and this permits the use of textile based vests for this application.

Their program adopted a rigorous scientific approach and collected data on human attack capacity. Two commercial knives were selected for use in this PSDB test method. In order to test at a representative velocity, an air cannon method was developed to propel the knife and sabot at the vest target using compressed air. The introduction of knives which cut fiber and a hard-dense test backing required stab vest manufactures to use metallic components in their vest designs to address this more rigorous standard.

This standard like the stab standards is based on drop testing with a test knife in a mounting of controlled mass. The Slash test uses the Stanley Utility knife or box cutter blades. The Slash standard tests cut resistance of the armor panel parallel to the direction of blade travel.

The test equipment measures the force at the instant the blade tip produces a sustained slash through the vest. The criteria requires that slash failure of the armor be greater than 80 newtons of force. Vests that combined stab and ballistic protection were a significant innovation in the s period of vest development.

This multi-threat approach is common in the United Kingdom and other European countries and is less popular in the USA. Unfortunately for multi-threat users, the metallic array and chainmail systems that were necessary to defeat the test blades offered little ballistic performance. The multi-threat vests have areal densities are close to the sum of the two solutions separately. These vests have mass values in the 7.

These designs were used extensively by the London Metropolitan Police Service and other agencies in the United Kingdom. As vest manufactures and the specifying authorities worked with these standards, the UK and US Standards teams began a collaboration on test methods. The use of commercial knives with inconsistent sharpness and tip shape created problems with test consistency.

The tissue simulants, Roma clay and gelatin, were either unrepresentative of tissue or not practical for the test operators. A composite-foam and hard-rubber test backing was developed as an alternative to address these issues. The drop test method was selected as the baseline for the updated standard over the air cannon option. The lowest level of this requirement at 25 joules was addressed by a series of textile products of both wovens, coated wovens and laminated woven materials.

All of these materials were based on Para-aramid fiber. The co-efficient of friction for ultra high molecular weigh polyethylene UHMWPE prevented its use in this application. These ceramic-coated products do not the flexibility and softness of un-coated textile materials. For the higher levels of protection L2 and L3, the very aggressive penetration of the small, thin P1 blade has resulted in the continued use of metallic components in stab armor.

In Germany, Mehler Vario Systems have developed sophisticated hybrid vests of woven para-aramid and chain mail their solution was selected by the London Metro Police. This system is currently implemented in Holland. In many countries there is also an interest to combine military style explosive fragmentation protection with bullet-ballistics and stab requirements.

In order for ballistic protection to be wearable the ballistic panels and hard rifle-resistant plates are fitted inside a special carrier. The carrier is the visible part of a ballistic vest. The most basic carrier includes pockets which hold the ballistic panels and straps for mounting the carrier on the user.

There are two major types of carriers: military or tactical carriers that are worn over the shirt, and covert law enforcement type carriers that are worn under the shirt. The military type of carrier, English police waistcoat carrier, or police tactical carrier most typically has a series of webbing, hook and loop, and snap type connectors on the front and back face. This permits the wearer to mount various gear to the carrier in many different configurations.

This load carriage feature is an important part of uniform and operational design for police weapons teams and the military. Individual pieces comprising the Modular Tactical Vest worn by U. Marines , including SAPI plates gray, at top left. In addition to load carriage, this type of carrier may include pockets for neck protection, side plates, groin plates, and backside protection. Because this style of carrier is not close fitting, sizing in this system is straightforward for both men and women, making custom fabrication unnecessary.

Army working dog, wearing a bullet-resistant vest, clears a building in Afghanistan. Law enforcement carriers in some countries are concealable. The carrier holds the ballistic panels close to the wearer's body and a uniform shirt is worn over the carrier. This type of carrier must be designed to conform closely to the officer's body shape.

For concealable armor to conform to the body it must be correctly fitted to a particular individual. Many programs specify full custom measurement and manufacturing of armor panels and carriers to ensure good fit and comfort for able armor. Officers who are either female or significantly overweight have more difficulty in getting accurately measured and having comfortable armor fabricated. A third textile layer is often found between the carrier and the ballistic components.

The ballistic panels are covered in a coated pouch or slip. This slip provides the encapsulation of the ballistic materials. Slips are manufactured in two types: heat sealed hermetic slips and simple sewn slips. For some ballistic fibers such as Kevlar the slip is a critical part of the system. The slip prevents moisture from the user's body from saturating the ballistic materials. This protection from moisture cycling increases the useful life of the armor. In recent years, advances in material science have opened the door to the idea of a literal "bulletproof vest" able to stop handgun and rifle bullets with a soft textile vest, without the assistance of additional metal or ceramic plating.

However, progress is moving at a slower rate compared to other technical disciplines. The most recent offering from Kevlar, Protera , was released in Current soft body armor can stop most handgun rounds which has been the case for roughly 15 years [ citation needed ] , but armor plates are needed to stop rifle rounds and steel core handgun rounds such as 7.

The para-aramids have not progressed beyond the limit of 23 grams per denier in fiber tenacity. Modest ballistic performance improvements have been made by new producers of this fiber type. Improvements in this material have been seen in the development of cross-plied non-woven laminate, e. Spectra Shield. The major ballistic performance advance of fiber PBO is known as a "cautionary tale" in materials science.

However this higher tenacity was delivered with a well-publicized weakness in environmental durability. Akzo-Magellan now DuPont teams have been working on fiber called M5 fiber ; however, its announced startup of its pilot plant has been delayed more than 2 years. Data suggests if the M5 material can be brought to market, its performance will be roughly equivalent to PBO. The Teijin emphasis appears to be on computational chemistry to define a solution to high tenacity without environmental weakness.

Research aims to develop artificial spider silk which could be super strong, yet light and flexible. Finer yarns and lighter woven fabrics have been a key factor in improved ballistic results. The cost of ballistic fiber goes up dramatically as yarn size goes down, so it is unclear how long this trend can continue. The current practical limit of fiber size is denier with most wovens limited at the denier level. Three-dimensional weaving with fibers connecting flat wovens together into a 3D system are being considered for both hard and soft ballistics.

Team Engineering Inc is designing and weaving these multi layer materials. Tex Tech has been working on these materials. Like the 3D weaving, Tex Tech sees the advantage in the 3-axis fiber orientation. When a ceramic plate is shot, it cracks in the vicinity of the impact, which reduces the protection in this area. Although NIJ This layer contains cracks in the strike face to the immediate area around an impact, resulting in markedly improved multi-hit ability; [37] in conjunction with NIJ IIIA soft armor, a 3.

The standards for armor-piercing rifle bullets are not clear-cut, because the penetration of a bullet depends on the hardness of the target armor, and the armor type. However, there are a few general rules. For example, bullets with a soft lead-core and copper jacket are too easily deformed to penetrate hard materials, whereas rifle bullets intended for maximum penetration into hard armor are nearly always manufactured with high-hardness core materials such as tungsten carbide.

Many common bullets, such as the 7. However, there is a caveat to this rule: with regards to penetration, the hardness of a bullet's core is significantly less important than the sectional density of that bullet. This is why there are many more bullets made with tungsten instead of tungsten carbide.

Additionally, as the hardness of the bullet core increases, so must the amount of ceramic plating used to stop penetration. Like in soft ballistics, a minimum ceramic material hardness of the bullet core is required to damage their respective hard core materials, however in armor-piercing rounds the bullet core is eroded rather than deformed.

The US Department of Defense uses several hard armor plates. SAPI plates have a black fabric cover with the text "7. ESAPI ceramic plates have a green fabric cover with the text "7. Depending on revision, the plate may stop more than one. The plates may be differentiated by the text "REV. Over , inserts were procured; [49] however, the AP threats they were meant to stop never materialized, and the plates were put into storage.

XSAPI plates are required to stop three rounds [50] of either the 7. Body armor standards in the Russian Federation , as established in GOST R , differ significantly from American standards, on account of a different security situation. The 7. Bomb disposal officers often wear heavy armor [59] [60] [61] designed to protect against most effects of a moderate sized explosion, such as bombs encountered in terror threats.

Full head helmet, covering the face and some degree of protection for limbs is mandatory in addition to very strong armor for the torso. An insert to protect the spine is usually applied to the back, in case an explosion throws the wearer. Visibility and mobility of the wearer is severely limited, as is the time that can be spent working on the device. Armor designed primarily to counter explosives is often somewhat less effective against bullets than armor designed for that purpose.

The sheer mass of most bomb disposal armor usually provides some protection, and bullet-specific trauma plates are compatible with some bomb disposal suits. Bomb disposal technicians try to accomplish their task if possible using remote methods e.

Actually laying hands on a bomb is only done in an extremely life-threatening situation, where the hazards to people and critical structures cannot be lessened by using wheeled robots or other techniques. It is notable that despite the protection offered, much of it is in fragmentation.

According to some sources, overpressure from ordinance beyond the charge of a typical hand grenade can overwhelm a bomb suit. In some media, an EOD suit is portrayed as a heavily armoured bulletproof suit capable of ignoring explosions and gunfire; In real life this is not the case, as much of a bomb suit is made up of only soft armor. In the mids the state of California Department of Corrections issued a requirement for a body armor using a commercial ice pick as the test penetrator.

The test method attempted to simulate the capacity of a human attacker to deliver impact energy with their upper body. As was later shown by the work of the former British PSDB, this test overstated the capacity of human attackers. The test used a drop mass or sabot that carried the ice pick. Using gravitational force, the height of the drop mass above the vest was proportional to the impact energy.

The ice pick has a 4 mm 0. The California standard did not include knife or cutting-edge weapons in the test protocol. In this early phase only titanium and steel plate offerings were successful in addressing this requirement. Point Blank developed the first ice pick certified offerings for CA Department of Corrections in shaped titanium sheet metal. Vests of this type are still in service in US corrections facilities as of The transition from hard, dense clay-based Roma to soft low-density gelatin allowed all textile solutions to meet this attack energy requirement.

Soon all textile "ice pick" vests began to be adopted by California and other US states as a result of this migration in the test methods. It is important for users to understand that the smooth, round tip of the ice pick does not cut fiber on impact and this permits the use of textile based vests for this application. The earliest of these "all" fabric vests designed to address this ice pick test was Warwick Mills's TurtleSkin ultra tightly woven para-aramid fabric with a patent filed in Their program adopted a rigorous scientific approach and collected data on human attack capacity.

Two commercial knives were selected for use in this PSDB test method. In order to test at a representative velocity, an air cannon method was developed to propel the knife and sabot at the vest target using compressed air. The introduction of knives which cut fiber and a hard-dense test backing required stab vest manufacturers to use metallic components in their vest designs to address this more rigorous standard.

This standard, like the stab standards, is based on drop testing with a test knife in a mounting of controlled mass. The slash test uses the Stanley Utility knife or box cutter blades. The slash standard tests the cut resistance of the armor panel parallel to the direction of blade travel.

The test equipment measures the force at the instant the blade tip produces a sustained slash through the vest. The criteria require that slash failure of the armor be greater than 80 newtons of force. Vests that combined stab and ballistic protection were a significant innovation in the s period of vest development.

However police forces were evaluating their "street threats" and requiring vests with both knife and ballistic protection. This multi-threat approach is common in the United Kingdom and other European countries and is less popular in the USA. Unfortunately for multi-threat users, the metallic array and chainmail systems that were necessary to defeat the test blades offered little ballistic performance.

The multi-threat vests have areal densities close to the sum of the two solutions separately. These vests have mass values in the 7. These designs were used extensively by the London Metropolitan Police Service and other agencies in the United Kingdom. As vest manufacturers and the specifying authorities worked with these standards, the UK and US Standards teams began a collaboration on test methods.

The use of commercial knives with inconsistent sharpness and tip shape created problems with test consistency. As a result, two new "engineered blades" were designed that could be manufactured to have reproducible penetrating behavior. The tissue simulants, Roma clay and gelatin, were either unrepresentative of tissue or not practical for the test operators. A composite-foam and hard-rubber test backing was developed as an alternative to address these issues. The drop test method was selected as the baseline for the updated standard over the air cannon option.

The drop mass was reduced from the "ice pick test" and a wrist-like soft linkage was engineered into the penetrator-sabot to create a more realistic test impact. The lowest level of this requirement at 25 joules was addressed by a series of textile products of both wovens, coated wovens and laminated woven materials. All of these materials were based on Para-aramid fiber.

The co-efficient of friction for ultra high molecular weight polyethylene UHMWPE prevented its use in this application. These ceramic-coated products do not have the flexibility and softness of un-coated textile materials. For the higher levels of protection L2 and L3, the very aggressive penetration of the small, thin P1 blade has resulted in the continued use of metallic components in stab armor.

In Germany, Mehler Vario Systems developed hybrid vests of woven para-aramid and chainmail, and their solution was selected by London's Metropolitan Police Service. This system is currently implemented in the Netherlands. In many countries there is also an interest to combine military style explosive fragmentation protection with bullet-ballistics and stab requirements.

In order for ballistic protection to be wearable, the ballistic panels and hard rifle-resistant plates are fitted inside a special carrier. The carrier is the visible part of a ballistic vest. The most basic carrier includes pockets which hold the ballistic panels and straps for mounting the carrier on the user. There are two major types of carriers: military or tactical carriers that are worn over the shirt, and covert law enforcement type carriers that are worn under the shirt.

The military type of carrier, English police waistcoat carrier, or police tactical carrier most typically has a series of webbing, hook and loop, and snap type connectors on the front and back face. This permits the wearer to mount various gear to the carrier in many different configurations.

This load carriage feature is an important part of uniform and operational design for police weapons teams and the military. In addition to load carriage, this type of carrier may include pockets for neck protection, side plates, groin plates, and backside protection. Because this style of carrier is not close fitting, sizing in this system is straightforward for both men and women, making custom fabrication unnecessary.

Law enforcement carriers in some countries are concealable. The carrier holds the ballistic panels close to the wearer's body and a uniform shirt is worn over the carrier. This type of carrier must be designed to conform closely to the officer's body shape. For concealable armor to conform to the body it must be correctly fitted to a particular individual. Many programs specify full custom measurement and manufacturing of armor panels and carriers to ensure good fit and comfortable armor.

Officers who are either female or significantly overweight have more difficulty in getting accurately measured and having comfortable armor fabricated. A third textile layer is often found between the carrier and the ballistic components. The ballistic panels are covered in a coated pouch or slip. This slip provides the encapsulation of the ballistic materials.

Slips are manufactured in two types: heat sealed hermetic slips and simple sewn slips. For some ballistic fibers such as Kevlar the slip is a critical part of the system. The slip prevents moisture from the user's body from saturating the ballistic materials. This protection from moisture cycling increases the useful life of the armor. The vast majority of hard body armor plates, including the U.

Monolithic plates are lighter than their non-monolithic counterparts, but suffer from reduced effectiveness when shot multiple times in a close area i. However, several non-monolithic armor systems have emerged, the most well-known being the controversial Dragon Skin system. Dragon Skin, composed of dozens of overlapping ceramic scales, promised superior multi-hit performance and flexibility compared to the then-current ESAPI plate; however, it failed to deliver. When the U. LIBA uses an innovative array of ceramic pellets embedded in a polyethylene backer; [71] [72] although this layout lacks the flexibility of Dragon Skin, it provides impressive multi-hit ability as well as the unique ability to repair the armor by replacing damaged pellets and epoxying them over.

Ballistic vests use layers of very strong fibers to "catch" and deform a bullet, mushrooming it into a dish shape, and spreading its force over a larger portion of the vest fiber. The vest absorbs the energy from the deforming bullet, bringing it to a stop before it can completely penetrate the textile matrix.

Some layers may be penetrated but as the bullet deforms, the energy is absorbed by a larger and larger fiber area. In recent years, advances in material science have opened the door to the idea of a literal "bulletproof vest" able to stop handgun and rifle bullets with a soft textile vest, without the assistance of additional metal or ceramic plating.

However, progress is moving at a slower rate compared to other technical disciplines. The most recent offering from Kevlar, Protera , was released in Current soft body armor can stop most handgun rounds which has been the case for roughly 15 years [ citation needed ] , but armor plates are needed to stop rifle rounds and steel-core handgun rounds such as 7.

The para-aramids have not progressed beyond the limit of 23 grams per denier in fiber tenacity. Modest ballistic performance improvements have been made by new producers of this fiber type. Improvements in this material have been seen in the development of cross-plied non-woven laminate, e.

Spectra Shield. The major ballistic performance advance of fiber PBO is known as a "cautionary tale" in materials science. However this higher tenacity was delivered with a well-publicized weakness in environmental durability. Akzo-Magellan now DuPont teams have been working on fiber called M5 fiber ; however, its announced startup of its pilot plant has been delayed more than 2 years. Data suggests if the M5 material can be brought to market, its performance will be roughly equivalent to PBO.

The Teijin emphasis appears to be on computational chemistry to define a solution to high tenacity without environmental weakness. The materials science of second generation "super" fibers is complex, requires large investments, and represent significant technical challenges. Research aims to develop artificial spider silk which could be super strong, yet light and flexible.

In , the US military began conducting research into the feasibility of using artificial silk as body armor, which has the advantages of its light weight and its cooling capability. Finer yarns and lighter woven fabrics have been a key factor in improving ballistic results. The cost of ballistic fibers increases dramatically as the yarn size decreases, so it's unclear how long this trend can continue.

The current practical limit of fiber size is denier with most wovens limited at the denier level. Three-dimensional weaving with fibers connecting flat wovens together into a 3D system are being considered for both hard and soft ballistics.

Team Engineering Inc is designing and weaving these multi layer materials. DSM feels this advanced material provides some improved performance, however the SB61 "soft ballistic" version has been recalled. Tex Tech has been working on these materials. Like the 3D weaving, Tex Tech sees the advantage in the 3-axis fiber orientation.

Ballistic nylon until the s or Kevlar, Twaron [84] or Spectra a competitor for Kevlar or polyethylene fiber could be used to manufacture bullet proof vests. Ceramic materials, materials processing and progress in ceramic penetration mechanics are significant areas of academic and industrial activity. This combined field of ceramics armor research is broad and is perhaps summarized best by The American Ceramics Society.

ACerS has run an annual armor conference for a number of years and compiled a proceedings — Large torso sized ceramic plates are complex to manufacture and are subject to cracking in use. Monolithic plates also have limited multi hit capacity as a result of their large impact fracture zone These are the motivations for new types of armor plate. These new designs use two- and three-dimensional arrays of ceramic elements that can be rigid, flexible or semi-flexible.

Dragon Skin body armor is one of these systems. European developments in spherical and hexagonal arrays have resulted in products that have some flex and multi hit performance. In addition advanced ceramic processing techniques arrays require adhesive assembly methods. One novel approach is use of hook and loop fasteners to assemble the ceramic arrays. Currently, there are a number of methods by which nanomaterials are being implemented into body armor production.

The first, developed at University of Delaware is based on nanoparticles within the suit that become rigid enough to protect the wearer as soon as a kinetic energy threshold is surpassed. These coatings have been described as shear thickening fluids. In an Israeli company, ApNano , developed a material that was always rigid.

It was announced that this nanocomposite based on tungsten disulfide nanotubes was able to withstand shocks generated by a steel projectile traveling at velocities of up to 1. During the tests, the material proved to be so strong that after the impact the samples remained essentially unmarred. As of mid, spider silk bulletproof vests and nano-based armors are being developed for potential market release. In late , researchers began studying and testing graphene as a material for use in body armor.

Graphene is manufactured from carbon and is the thinnest, strongest, and most conductive material on the planet. Taking the form of hexagonally arranged atoms, its tensile strength is known to be times greater than steel, but studies from Rice University have revealed it is also 10 times better than steel at dissipating energy, an ability that had previously not been thoroughly explored. To test its properties, the University of Massachusetts stacked together graphene sheets only a single carbon atom thick, creating layers ranging in thickness from 10 nanometers to nanometers from layers.

Microscopic spherical silica "bullets" were fired at the sheets at speeds of up to 3 km 1. Upon impact, the projectiles deformed into a cone shape around the graphene before ultimately breaking through. In the three nanoseconds it held together however, the transferred energy traveled through the material at a speed of If the impact stress can be spread out over a large enough area that the cone moves out at an appreciable velocity compared with the velocity of the projectile, stress will not be localized under where it hit.

Although a wide impact hole opened up, a composite mixture of graphene and other materials could be made to create a new, revolutionary armor solution. In Australia, it is illegal to import body armour without prior authorisation from Australian Customs and Border Protection Service. United States law restricts possession of body armor for convicted violent felons. Many U. In other states, such as Kentucky , possession is not prohibited, but probation or parole is denied to a person convicted of committing certain violent crimes while wearing body armor and carrying a deadly weapon.

Most states do not have restrictions for non-felons. In all Canadian provinces except for Alberta , British Columbia and Manitoba , it is legal to wear and to purchase body armour such as ballistic vests. Under the laws of these provinces, it is illegal to possess body armour without a license unless exempted issued by the provincial government.

Nova Scotia has passed similar laws, but they are not yet in force. According to the Body Armour Control Act of Alberta which came into force on June 15, , any individual in possession of a valid firearms licence under the Firearms Act of Canada can legally purchase, possess and wear body armour. Furthermore, a number of laws and court rulings during the years have rehearsed the concept of a ballistic vest being mandatory to wear for those individuals who work in the private security sector.

In the Netherlands the civilian ownership of body armour is subject to the European Union regulations. Body armour in various ballistic grades is sold by a range of different vendors, mainly aimed at providing to security guards and VIP's.

The use of body armour while committing a crime is not an additional offense in itself, but may be interpreted as so under different laws such as resisting arrest. From Wikipedia, the free encyclopedia. Form of body armor that protects the torso from some projectiles. This article's lead section may be too short to adequately summarize the key points. Please consider expanding the lead to provide an accessible overview of all important aspects of the article.

August See also: Steel Bib. Main article: List of body armor performance standards. Main article: Bomb suit. See also: Stab vest. Archived from the original on Retrieved Boston : Brill Academic Publishers. ISBN The Cork Examiner. December 6, Encyclopedia of Western Gunfighters. University of Oklahoma Press.

The Encyclopedia of Lawmen, Outlaws, and Gunfighters. Checkmark Books. The Truth about Wyatt Earp 2nd ed. Carpinteria, CA: O. The Prescott Courier. George Goodfellow".

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The Evolution of Crime Fighting Tools Ep 11 - Bullet Proof Vest

A bulletproof vest, also known as a ballistic vest or a bullet-resistant vest, is an item of body armor that helps absorb the impact and reduce or stop. Kevlar used in the vests is comprised of a woven fabric consisting of synthetic fibres made through polymerisation. It is a high strength material known for. Bulletproof vests are made from a very strong, very durable fibre called aramid. Aramid was originally designed for use in tyres but was later shown to be.