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50-449: The fabric is often combined with Kevlar to increase its resistance for breakage or tear. Nomex and related aramid polymers are related to nylon , but have aromatic backbones, and hence are more rigid and more durable. Nomex is an example of a meta variant of the aramids ( Kevlar is a para aramid). Unlike Kevlar, Nomex strands cannot align during filament polymerization and have less strength: its ultimate tensile strength

100-436: A relative density of 1.44 (0.052 lb/in ). The polymer owes its high strength to the many inter-chain bonds. These inter-molecular hydrogen bonds form between the carbonyl groups and N H centers. Additional strength is derived from aromatic stacking interactions between adjacent strands. These interactions have a greater influence on Kevlar than the van der Waals interactions and chain length that typically influence

150-436: A $ 5 million grant to research the use of the fabric in bullet-proof vests. Kevlar 149 was invented by Jacob Lahijani of Dupont in the 1980s. Kevlar is synthesized in solution from the monomers 1,4- phenylene -di amine ( para -phenylenediamine ) and terephthaloyl chloride in a condensation reaction yielding hydrochloric acid as a byproduct. The result has liquid-crystalline behavior, and mechanical drawing orients

200-426: A key component in their construction. Other military uses include bulletproof face masks and spall liners used to protect the crews of armoured fighting vehicles . Nimitz -class aircraft carriers use Kevlar reinforcement in vital areas. Civilian applications include: high heat resistance uniforms worn by firefighters, body armour worn by police officers, security, and police tactical teams such as SWAT . Kevlar

250-489: A price range much higher than average cost of basketball shoes. It was also used in the laces for the Adidas F50 adiZero Prime football boot. Several companies, including Continental AG , manufacture cycle tires with Kevlar to protect against punctures. Folding-bead bicycle tires, introduced to cycling by Tom Ritchey in 1984, use Kevlar as a bead in place of steel for weight reduction and strength. A side effect of

300-499: A rigid and lightweight plate is produced, which can improve the efficiency of the soundboard. While the 'laminated' technique was created by Matthias Dammann, the use of Nomex within was first employed by luthier Gernot Wagner. The deaths in fiery crashes of race car drivers Fireball Roberts at Charlotte, and Eddie Sachs and Dave MacDonald at Indianapolis in 1964, led to the use of flame-resistant fabrics such as Nomex. In early 1966 Competition Press and Autoweek reported: "During

350-554: A spacecraft surface and prevent damage. Most of the free-flyer's systems are derived from the development of the Simplified Aid For EVA Rescue (SAFER) backpack. The AERCam's thrusters, basic avionics, solid-state rate sensors , attitude hold electronics, nitrogen tank and hand controller are identical to those used on the SAFER. The AERCam thrusters, however, produce eight-hundredths of a pound of thrust while

400-418: Is 340 MPa (49,000 psi). However, it has excellent thermal, chemical, and radiation resistance for a polymer material. It can withstand temperatures of up to 370 °C (700 °F). Nomex is produced by condensation reaction from the monomers m -phenylenediamine and isophthaloyl chloride . It is sold in both fiber and sheet forms and is used as a fabric where resistance from heat and flame

450-493: Is a 14-inch-diameter (360 mm), 35-pound (16 kg) sphere that contains two television cameras, an avionics system and 12 small nitrogen gas-powered thrusters . The sphere, which looks like an oversized soccer ball , was released by Mission Specialist Winston E. Scott during the STS-87 spacewalk and flew freely in the forward cargo bay for about 30 minutes. The free-flyer was remotely controlled by Pilot Steven W. Lindsey from

500-605: Is a common piece of racing and firefighting equipment. It is placed on the head on top of a firefighter 's face mask. The hood protects the portions of the head not covered by the helmet and face mask from the intense heat of the fire. Wildland firefighters wear Nomex shirts and trousers as part of their personal protective equipment during wildfire suppression activities. Racing car drivers wear driving suits constructed of Nomex and or other fire retardant materials , along with Nomex gloves, long underwear, balaclavas , socks, helmet lining and shoes, to protect them in

550-591: Is a strong, heat-resistant synthetic fiber , related to other aramids such as Nomex and Technora . Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires. It is typically spun into ropes or fabric sheets that can be used as such, or as an ingredient in composite material components. Kevlar has many applications, ranging from bicycle tires and racing sails to bulletproof vests , all due to its high tensile strength-to-weight ratio ; by this measure it

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600-887: Is also found as a braid layer used on the outside of hose assemblies, to add protection against sharp objects. Some cellphones (including the Motorola RAZR Family , the Motorola Droid Maxx , OnePlus 2 and Pocophone F1 ) have a Kevlar backplate, chosen over other materials such as carbon fiber due to its resilience and lack of interference with signal transmission. The Kevlar fiber/epoxy matrix composite materials can be used in marine current turbines (MCT) or wind turbines due to their high specific strength and light weight compared to other fibers. Aramid fibers are widely used for reinforcing composite materials, often in combination with carbon fiber and glass fiber . The matrix for high performance composites

650-422: Is five times stronger than steel. It is also used to make modern marching drumheads that withstand high impact; and for mooring lines and other underwater applications. A similar fiber called Twaron with the same chemical structure was developed by Akzo in the 1970s; commercial production started in 1986, and Twaron is manufactured by Teijin . Poly-paraphenylene terephthalamide (K29) – branded Kevlar –

700-532: Is one application, Kevlar being less prone than carbon or glass fiber to break in bird collisions. AERCam Sprint The Autonomous Extravehicular Activity Robotic Camera Sprint (AERCam Sprint) is a NASA experiment to demonstrate the use of a prototype free-flying television camera. It was tested on STS-87 and could also be used for remote inspections of the exterior of the International Space Station . The AERCam Sprint free-flyer

750-460: Is required. Nomex sheet is actually a calendered paper and made in a similar fashion. Nomex Type 410 paper was the first Nomex paper developed and one of the higher volume grades made, mostly for electrical insulation purposes. Wilfred Sweeny (1926–2011), the DuPont scientist responsible for discoveries leading to Nomex, earned a DuPont Lavoisier Medal in 2002 partly for this work. Nomex Paper

800-409: Is slightly stronger at low temperatures. At higher temperatures the tensile strength is immediately reduced by about 10–20%, and after some hours the strength progressively reduces further. For example: enduring 160 °C (320 °F) for 500 hours, its strength is reduced by about 10%; and enduring 260 °C (500 °F) for 70 hours, its strength is reduced by about 50%. Kevlar is often used in

850-440: Is used in electrical laminates such as circuit boards and transformer cores as well as fireproof honeycomb structures where it is saturated with a phenolic resin . Honeycomb structures such as these, as well as mylar -Nomex laminates, are used extensively in aircraft construction. Firefighting, military aviation, and vehicle racing industries use Nomex to create clothing and equipment that can withstand intense heat. A Nomex hood

900-440: Is used in rope and in cable, where the fibers are kept parallel within a polyethylene sleeve. The cables have been used in suspension bridges such as the bridge at Aberfeldy, Scotland . They have also been used to stabilize cracking concrete cooling towers by circumferential application followed by tensioning to close the cracks. Kevlar is widely used as a protective outer sheath for optical fiber cable , as its strength protects

950-401: Is used to manufacture gloves, sleeves, jackets, chaps and other articles of clothing designed to protect users from cuts, abrasions and heat. Kevlar-based protective gear is often considerably lighter and thinner than equivalent gear made of more traditional materials. It is used for motorcycle safety clothing , especially in the areas featuring padding such as the shoulders and elbows. In

1000-421: Is usually epoxy resin . Typical applications include monocoque bodies for Formula 1 cars, helicopter rotor blades, tennis , table tennis , badminton and squash rackets , kayaks , cricket bats , and field hockey , ice hockey and lacrosse sticks. Kevlar 149, the strongest fiber and most crystalline in structure, is an alternative in certain parts of aircraft construction. The wing leading edge

1050-499: Is usually a resin poured onto the Kevlar to make the head airtight, and a nylon top layer to provide a flat striking surface. This is one of the primary types of marching snare drum heads. Remo 's Falam Slam patch is made with Kevlar and is used to reinforce bass drum heads where the beater strikes. Kevlar is used in the woodwind reeds of Fibracell. The material of these reeds is a composite of aerospace materials designed to duplicate

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1100-554: The NA48 experiment at CERN to separate a vacuum vessel from a vessel at nearly atmospheric pressure, both 192 cm (76 in) in diameter. The window has provided vacuum tightness combined with reasonably small amount of material (only 0.3% to 0.4% of radiation length ). Kevlar is a well-known component of personal armor such as combat helmets , ballistic face masks , and ballistic vests . The PASGT helmet and vest that were used by United States military forces used Kevlar as

1150-480: The Stiletto 27 . Nomex is used in industrial applications as a filter in exhaust filtration systems, typically a baghouse , that deal with hot gas emissions found in asphalt plants, cement plants, steel smelting facilities, and non-ferrous metal production facilities. Nomex is used in some classical guitar tops in order to create a 'composite' soundboard. When Nomex is laminated between 2 spruce or cedar 'skins',

1200-602: The Mini-AERCam Robotic Space Vehicle. The free-flying robotic inspection vehicle was designed circa 2005 for remote viewing and inspection on human spaceflight missions. "The nanosatellite-class spherical Mini AERCam (Miniature Autonomous Extravehicular Robotic Camera) is just 7.5 inches (190 mm) in diameter and weighs approximately 10 pounds (4.5 kg)." The inspection vehicle moves by means of twelve cold-gas xenon thrusters for attitude and position control, distributed in four thruster pods on

1250-443: The SAFER thrusters produced eight-tenths of a pound of thrust. The free-flyer is powered by lithium batteries . Its electrical supply and nitrogen supply are designed to last at least seven hours, the maximum length of a normal spacewalk . The AERCam sphere has a small floodlight built in that is identical to floodlights used on the spacesuit helmets. Spaced equally around the sphere also are six small, flashing yellow LEDs that make

1300-533: The Shuttle's aft flight deck using a hand controller, two laptop computers and a window-mounted antenna. The AERCam is designed to fly very slowly at a rate of less than one-quarter of a foot per second. Remote control of the AERCam is performed through two-way UHF radio communications, with data regarding the status of the free-flyer's systems transmitted back to the operator. Television images are transmitted back to

1350-657: The U.S. space program, Nomex has been used for the Thermal Micrometeoroid Garment on the Extravehicular Mobility Unit (in conjunction with Kevlar and Gore-Tex ) and ACES pressure suit, both for fire and extreme environment (water immersion to near vacuum) protection, and as thermal blankets on the payload bay doors, fuselage, and upper wing surfaces of the Space Shuttle Orbiter. It has also been used for

1400-902: The airbags for the Mars Pathfinder and Mars Exploration Rover missions , the Galileo atmospheric probe , the Cassini-Huygens Titan probe, as an external covering on the AERCam Sprint , and is planned to be incorporated into NASA's upcoming Crew Exploration Vehicle . Nomex has been used as an acoustic material in Troy, NY, at Rensselaer Polytechnic Institute's Experimental Media and Performing Arts Center ( EMPAC ) main concert hall. A ceiling canopy of Nomex reflects high and mid frequency sound, providing reverberation, while letting lower frequency sound partially pass through

1450-400: The bow's user. To date, the only manufacturer of this type of bow is CodaBow . Kevlar is also presently used as a material for tailcords (a.k.a. tailpiece adjusters), which connect the tailpiece to the endpin of bowed string instruments. Kevlar is sometimes used as a material on marching snare drums. It allows for an extremely high amount of tension, resulting in a cleaner sound. There

1500-487: The cable from damage and kinking. When used in this application it is commonly known by the trademarked name Parafil. Kevlar was used by scientists at Georgia Institute of Technology as a base textile for an experiment in electricity-producing clothing. This was done by weaving zinc oxide nanowires into the fabric. If successful, the new fabric will generate about 80 milliwatts per square meter. A retractable roof of over 60,000 sq ft (5,600 m ) of Kevlar

1550-546: The canopy. According to RPI President Shirley Ann Jackson, EMPAC is the first venue in the world to use Nomex as an architectural material for acoustic reasons. Nomex (like Kevlar) is also used in the production of loudspeaker drivers. Honeycomb-structured Nomex paper is used as a spacer between layers of lead in the ATLAS Liquid Argon Calorimeter, and as a laminate core for hull and deck construction in custom boats such as Stiletto Catamarans like

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1600-437: The carcinogenic properties associated with asbestos. Wicks for fire dancing props are made of composite materials with Kevlar in them. Kevlar by itself does not absorb fuel very well, so it is blended with other materials such as fiberglass or cotton . Kevlar's high heat resistance allows the wicks to be reused many times. Kevlar is sometimes used as a substitute for Teflon in some non-stick frying pans. Kevlar fiber

1650-416: The event of a fire . Military pilots and aircrew wear flight suits made of over 92 percent Nomex to protect them from cockpit fires. It is also worn as sailors' anti-flash gear . Troops riding in ground vehicles often wear Nomex for fire protection. Kevlar thread is often used to hold the fabric together at seams. Military tank drivers also typically use Nomex hoods as protection against fire. In

1700-438: The field of cryogenics for its low thermal conductivity and high strength relative to other materials for suspension purposes. It is most often used to suspend a paramagnetic salt enclosure from a superconducting magnet mandrel in order to minimize any heat leaks to the paramagnetic material. It is also used as a thermal standoff or structural support where low heat leaks are desired. A thin Kevlar window has been used by

1750-527: The first time. It launched the Elite II Series, with enhancements to its earlier version of basketball shoes by using Kevlar in the anterior as well as the shoe laces . This was done to decrease the elasticity of the tip of the shoe in contrast to the nylon conventionally used, as Kevlar expanded by about 1% against nylon which expanded by about 30%. Shoes in this range included LeBron, HyperDunk and Zoom Kobe VII. However these shoes were launched at

1800-583: The folding bead is a reduction in shelf and floor space needed to display cycle tires in a retail environment, as they are folded and placed in small boxes. Kevlar has also been found to have useful acoustic properties for loudspeaker cones, specifically for bass and mid range drive units. Additionally, Kevlar has been used as a strength member in fiber optic cables such as the ones used for audio data transmissions. Kevlar can be used as an acoustic core on bows for string instruments . Kevlar's physical properties provide strength, flexibility, and stability for

1850-432: The free-flyer visible to the operator in darkness. The front of the sphere is marked by stripes and arrows while the back is marked by dots. These markings assist the operator in determining the orientation of the AERCam. A small fabric strap on the sphere serves as a handhold for the spacewalker while deploying and retrieving the free flyer. NASA designed a follow-on autonomous or teleoperated prototype vehicle called

1900-411: The idea developed: "We folded it over a couple of times and shot at it. The bullets didn't go through." In tests, they strapped Kevlar onto anesthetized goats and shot at their hearts, spinal cords, livers and lungs. They monitored the goats' heart rate and blood gas levels to check for lung injuries. After 24 hours, one goat died and the others had wounds that were not life threatening. Shubin received

1950-486: The more expensive hemp . It is one of the main materials used for paraglider suspension lines. It is used as an inner lining for some bicycle tires to prevent punctures. In table tennis , plies of Kevlar are added to custom ply blades, or paddles, in order to increase bounce and reduce weight. Tennis racquets are sometimes strung with Kevlar. It is used in sails for high performance racing boats. In 2013, with advancements in technology, Nike used Kevlar in shoes for

2000-461: The operator via a one-way S-band communications link. During the experiment operations, live television images were also relayed via Columbia to Mission Control. Two miniature color television cameras are mounted on the free-flyer, one with a 6 millimeter lens and another with a 12 millimeter lens. The exterior of the free-flyer sphere is covered with a 6 ⁄ 10 -inch-thick (15 mm) layer of Nomex felt to cushion any inadvertent contact with

2050-491: The past season, experimental driving suits were worn by Walt Hansgen , Masten Gregory , Marvin Panch and Group 44's Bob Tullius ; these four representing a fairly good cross section in the sport. The goal was to get use-test information on the comfort and laundering characteristics of Nomex. The Chrysler-Plymouth team at the recent Motor Trend 500 at Riverside also wore these suits." Kevlar Kevlar (para-aramid)

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2100-473: The polymer chains in the fiber's direction. Hexamethylphosphoramide (HMPA) was the solvent initially used for the polymerization , but for safety reasons, DuPont replaced it by a solution of N -methyl-pyrrolidone and calcium chloride. As this process had been patented by Akzo (see above) in the production of Twaron , a patent war ensued. Kevlar production is expensive because of the difficulties arising from using concentrated sulfuric acid , needed to keep

2150-547: The properties of other synthetic polymers and fibers such as ultra-high-molecular-weight polyethylene . The presence of salts and certain other impurities, especially calcium , could interfere with the strand interactions and care is taken to avoid inclusion in its production. Kevlar's structure consists of relatively rigid molecules which tend to form mostly planar sheet-like structures rather like silk protein. Kevlar maintains its strength and resilience down to cryogenic temperatures (−196 °C (−320.8 °F)): in fact, it

2200-466: The sport of fencing it is used in the protective jackets, breeches, plastrons and the bib of the masks. It is increasingly being used in the peto , the padded covering which protects the picadors ' horses in the bullring. Speed skaters also frequently wear an under-layer of Kevlar fabric to prevent potential wounds from skates in the event of a fall or collision. In kyudo , or Japanese archery , it may be used for bow strings , as an alternative to

2250-425: The water-insoluble polymer in solution during its synthesis and spinning . Several grades of Kevlar are available: The ultraviolet component of sunlight degrades and decomposes Kevlar, a problem known as UV degradation , and so it is rarely used outdoors without protection against sunlight. When Kevlar is spun , the resulting fiber has a tensile strength of about 3,620 MPa (525,000 psi) , and

2300-492: The way nature constructs cane reed. Very stiff but sound absorbing Kevlar fibers are suspended in a lightweight resin formulation. Kevlar is sometimes used in structural components of cars, especially high-value performance cars such as the Ferrari F40 . The chopped fiber has been used as a replacement for asbestos in brake pads . Aramids such as Kevlar release less airborne fibres than asbestos brakes and do not have

2350-438: Was "cloudy, opalescent upon being stirred, and of low viscosity " and usually was thrown away. However, Kwolek persuaded the technician, Charles Smullen, who ran the spinneret , to test her solution, and was amazed to find that the fiber did not break, unlike nylon . Her supervisor and her laboratory director understood the significance of her discovery and a new field of polymer chemistry quickly arose. By 1971, modern Kevlar

2400-530: Was a key part of the design of the Olympic Stadium, Montreal for the 1976 Summer Olympics . It was spectacularly unsuccessful, as it was completed 10 years late and replaced just 10 years later in May 1998 after a series of problems. Kevlar can be found as a reinforcing layer in rubber bellows expansion joints and rubber hoses , for use in high temperature applications, and for its high strength. It

2450-583: Was introduced. However, Kwolek was not very involved in developing the applications of Kevlar. In 1971, Lester Shubin , who was then the Director of Science and Technology for the National Institute for Law Enforcement and Criminal Justice, suggested using Kevlar to replace nylon in bullet-proof vests. Prior to the introduction of Kevlar, flak jackets made of nylon had provided much more limited protection to users. Shubin later recalled how

2500-488: Was invented by the Polish-American chemist Stephanie Kwolek while working for DuPont, in anticipation of a gasoline shortage. In 1964, her group began searching for a new lightweight strong fiber to use for light, but strong, tires. The polymers she had been working with, poly-p-phenylene-terephthalate and polybenzamide, formed liquid crystals in solution, something unique to polymers at the time. The solution

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