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Carbon fiber-reinforced polymers (
American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...
), carbon-fibre-reinforced polymers (
Commonwealth English The use of the English language in current and former member countries of the Commonwealth of Nations was largely inherited from British colonisation, with some exceptions. English serves as the medium of inter-Commonwealth relations. Many ...
), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light
fiber-reinforced plastic Fibre-reinforced plastic (FRP; also called fibre-reinforced polymer, or in American English ''fiber'') is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass (in fibreglass), carbon (in carbon-fi ...
s that contain
carbon fibers Carbon fibers or carbon fibres (alternatively CF, graphite fiber or graphite fibre) are fibers about in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages: high stiffness, high tensile strength, high stren ...
. CFRPs can be expensive to produce, but are commonly used wherever high
strength-to-weight ratio The specific strength is a material's (or muscle's) strength (force per unit area at failure) divided by its density. It is also known as the strength-to-weight ratio or strength/weight ratio or strength-to-mass ratio. In fiber or textile appli ...
and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester,
vinyl ester left, 144px, Vinyl acetate is a commercially important monomer that is classified as a vinyl ester (i.e. an ester of vinyl alcohol). Vinyl ester refers to esters formerly derived from vinyl alcohol. Commercially important examples of these mono ...
, or nylon, are sometimes used. The properties of the final CFRP product can be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other additives such as rubber and
carbon nanotube A scanning tunneling microscopy image of a single-walled carbon nanotube Rotating single-walled zigzag carbon nanotube A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers. ''Single-wall carbon nan ...
s can be used. Carbon fiber is sometimes referred to as ''graphite-reinforced polymer'' or ''graphite fiber-reinforced polymer'' (''GFRP'' is less common, as it clashes with glass-(fiber)-reinforced polymer).


Properties

CFRP are composite materials. In this case the composite consists of two parts: a matrix and a reinforcement. In CFRP the reinforcement is carbon fiber, which provides its strength. The matrix is usually a polymer resin, such as epoxy, to bind the reinforcements together. Because CFRP consists of two distinct elements, the material properties depend on these two elements. Reinforcement gives CFRP its strength and rigidity, measured by stress and elastic modulus respectively. Unlike
isotropic Isotropy is uniformity in all orientations; it is derived . Precise definitions depend on the subject area. Exceptions, or inequalities, are frequently indicated by the prefix ' or ', hence ''anisotropy''. ''Anisotropy'' is also used to describe ...
materials like steel and aluminum, CFRP has directional strength properties. The properties of CFRP depend on the layouts of the carbon fiber and the proportion of the carbon fibers relative to the polymer. The two different equations governing the net elastic modulus of composite materials using the properties of the carbon fibers and the polymer matrix can also be applied to carbon fiber reinforced plastics. The following equation, :E_c = V_mE_m + V_fE_f is valid for composite materials with the fibers oriented in the direction of the applied load. E_c is the total composite modulus, V_m and V_f are the volume fractions of the matrix and fiber respectively in the composite, and E_m and E_f are the elastic moduli of the matrix and fibers respectively. The other extreme case of the elastic modulus of the composite with the fibers oriented transverse to the applied load can be found using the following equation: :E_c = \left( \frac + \frac \right)^ The fracture toughness of carbon fiber reinforced plastics is governed by the following mechanisms: 1) debonding between the carbon fiber and polymer matrix, 2) fiber pull-out, and 3) delamination between the CFRP sheets. Typical epoxy-based CFRPs exhibit virtually no plasticity, with less than 0.5% strain to failure. Although CFRPs with epoxy have high strength and elastic modulus, the brittle fracture mechanics present unique challenges to engineers in failure detection since failure occurs catastrophically. As such, recent efforts to toughen CFRPs include modifying the existing epoxy material and finding alternative polymer matrix. One such material with high promise is
PEEK Polyether ether ketone (PEEK) is a colourless organic thermoplastic polymer in the polyaryletherketone (PAEK) family, used in engineering applications. The polymer was first developed in November 1978, later being introduced to the market by ...
, which exhibits an order of magnitude greater toughness with similar elastic modulus and tensile strength. However, PEEK is much more difficult to process and more expensive. Despite its high initial strength-to-weight ratio, a design limitation of CFRP is its lack of a definable fatigue limit. This means, theoretically, that stress cycle failure cannot be ruled out. While steel and many other structural metals and alloys do have estimable fatigue or endurance limits, the complex failure modes of composites mean that the fatigue failure properties of CFRP are difficult to predict and design against. As a result, when using CFRP for critical cyclic-loading applications, engineers may need to design in considerable strength safety margins to provide suitable component reliability over its service life. Environmental effects such as temperature and humidity can have profound effects on the polymer-based composites, including most CFRPs. While CFRPs demonstrate excellent corrosion resistance, the effect of moisture at wide ranges of temperatures can lead to degradation of the mechanical properties of CFRPs, particularly at the matrix-fiber interface. While the carbon fibers themselves are not affected by the moisture diffusing into the material, the moisture plasticizes the polymer matrix. This led to significant changes in properties that are dominantly influenced by the matrix in CFRPs such as compressive, interlaminar shear, and impact properties. The epoxy matrix used for engine fan blades is designed to be impervious against jet fuel, lubrication, and rain water, and external paint on the composites parts is applied to minimize damage from ultraviolet light. Carbon fibers can cause
galvanic corrosion Galvanic corrosion (also called bimetallic corrosion or dissimilar metal corrosion) is an electrochemical process in which one metal corrodes preferentially when it is in electrical contact with another, in the presence of an electrolyte. A sim ...
when CRP parts are attached to aluminum or mild steel but not to stainless steel or titanium. Carbon Fiber Reinforced Plastics are very hard to machine, and causes significant tool wear. The tool wear in CFRP machining is dependent on the fiber orientation and machining condition of the cutting process. To reduce tool wear various types of coated tools are used in machining CFRP and CFRP-metal stack.


Manufacture

The primary element of CFRP is a carbon filament; this is produced from a precursor polymer such as polyacrylonitrile (PAN), rayon, or petroleum pitch. For synthetic polymers such as PAN or rayon, the precursor is first spun into filament yarns, using chemical and mechanical processes to initially align the polymer chains in a way to enhance the final physical properties of the completed carbon fiber. Precursor compositions and mechanical processes used during spinning filament yarns may vary among manufacturers. After drawing or spinning, the polymer filament yarns are then heated to drive off non-carbon atoms (
carbonization Carbonization is the conversion of organic matters like plants and dead animal remains into carbon through destructive distillation. Complexity in carbonization Carbonization is a pyrolytic reaction, therefore, is considered a complex process ...
), producing the final carbon fiber. The carbon fibers filament yarns may be further treated to improve handling qualities, then wound on to
bobbin A bobbin or spool is a spindle or cylinder, with or without flanges, on which yarn, thread, wire, tape or film is wound. Bobbins are typically found in industrial textile machinery, as well as in sewing machines, fishing reels, tape measures, ...
s. From these fibers, a unidirectional sheet is created. These sheets are layered onto each other in a quasi-isotropic layup, e.g. 0°, +60°, or −60° relative to each other. From the elementary fiber, a bidirectional woven sheet can be created, i.e. a twill with a 2/2 weave. The process by which most CFRPs are made varies, depending on the piece being created, the finish (outside gloss) required, and how many of the piece will be produced. In addition, the choice of matrix can have a profound effect on the properties of the finished composite. Many CFRP parts are created with a single layer of carbon fabric that is backed with fiberglass. A tool called a chopper gun is used to quickly create these composite parts. Once a thin shell is created out of carbon fiber, the chopper gun cuts rolls of fiberglass into short lengths and sprays resin at the same time, so that the fiberglass and resin are mixed on the spot. The resin is either external mix, wherein the hardener and resin are sprayed separately, or internal mixed, which requires cleaning after every use. Manufacturing methods may include the following:


Molding

One method of producing CFRP parts is by layering sheets of carbon fiber cloth into a mold in the shape of the final product. The alignment and weave of the cloth fibers is chosen to optimize the strength and stiffness properties of the resulting material. The mold is then filled with epoxy and is heated or air-cured. The resulting part is very corrosion-resistant, stiff, and strong for its weight. Parts used in less critical areas are manufactured by draping cloth over a mold, with epoxy either preimpregnated into the fibers (also known as '' pre-preg'') or "painted" over it. High-performance parts using single molds are often vacuum-bagged and/or
autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizat ...
-cured, because even small air bubbles in the material will reduce strength. An alternative to the autoclave method is to use internal pressure via inflatable air bladders or EPS foam inside the non-cured laid-up carbon fiber.


Vacuum bagging

For simple pieces of which relatively few copies are needed (1–2 per day), a vacuum bag can be used. A fiberglass, carbon fiber, or aluminum mold is polished and waxed, and has a
release agent A release agent (also mold release agent, release coating, or mold release coating) is a chemical used to prevent other materials from bonding to surfaces. It can provide a solution in processes involving mold release, die-cast release, plastic re ...
applied before the fabric and resin are applied, and the vacuum is pulled and set aside to allow the piece to cure (harden). There are three ways to apply the resin to the fabric in a vacuum mold. The first method is manual and called a wet layup, where the two-part resin is mixed and applied before being laid in the mold and placed in the bag. The other one is done by infusion, where the dry fabric and mold are placed inside the bag while the vacuum pulls the resin through a small tube into the bag, then through a tube with holes or something similar to evenly spread the resin throughout the fabric. Wire loom works perfectly for a tube that requires holes inside the bag. Both of these methods of applying resin require hand work to spread the resin evenly for a glossy finish with very small pin-holes. A third method of constructing composite materials is known as a dry layup. Here, the carbon fiber material is already impregnated with resin (pre-preg) and is applied to the mold in a similar fashion to adhesive film. The assembly is then placed in a vacuum to cure. The dry layup method has the least amount of resin waste and can achieve lighter constructions than wet layup. Also, because larger amounts of resin are more difficult to bleed out with wet layup methods, pre-preg parts generally have fewer pinholes. Pinhole elimination with minimal resin amounts generally require the use of
autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizat ...
pressures to purge the residual gases out.


Compression molding

A quicker method uses a compression mold, also commonly known as carbon fiber forging. This is a two (male and female), or multi-piece mold, usually made out of aluminum or steel and more recently 3d printed plastic. The mold components are pressed together with the fabric and resin loaded into the inner cavity that ultimately becomes the desired component. The benefit is the speed of the entire process. Some car manufacturers, such as BMW, claimed to be able to cycle a new part every 80 seconds. However, this technique has a very high initial cost since the molds require CNC machining of very high precision.


Filament winding

For difficult or convoluted shapes, a filament winder can be used to make CFRP parts by winding filaments around a mandrel or a core.


Applications

Applications for CFRP include the following:


Aerospace engineering

The
Airbus A350 XWB The Airbus A350 is a long-range, wide-body twin-engine jet airliner developed and produced by Airbus. The first A350 design proposed by Airbus in 2004, in response to the Boeing 787 Dreamliner, would have been a development of the A330 ...
is built of 52% CFRP including wing spars and fuselage components, overtaking the
Boeing 787 Dreamliner The Boeing 787 Dreamliner is an American Wide-body aircraft, wide-body jet airliner developed and manufactured by Boeing Commercial Airplanes. After dropping its unconventional Boeing Sonic Cruiser, Sonic Cruiser project, Boeing announced th ...
, for the aircraft with the highest weight ratio for CFRP, which is 50%. This was one of the first commercial aircraft to have wing spars made from composites. The
Airbus A380 The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner. Airbus studies started in 1988, and the project was annou ...
was one of the first commercial airliners to have a central wing-box made of CFRP; it is the first to have a smoothly contoured wing cross-section instead of the wings being partitioned span-wise into sections. This flowing, continuous cross section optimises aerodynamic efficiency. Moreover, the trailing edge, along with the rear bulkhead,
empennage The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...
, and un-pressurised fuselage are made of CFRP. However, many delays have pushed order delivery dates back because of problems with the manufacture of these parts. Many aircraft that use CFRP have experienced delays with delivery dates due to the relatively new processes used to make CFRP components, whereas metallic structures have been studied and used on airframes for years, and the processes are relatively well understood. A recurrent problem is the monitoring of structural ageing, for which new methods are constantly investigated, due to the unusual multi-material and anisotropic nature of CFRP. In 1968 a ''Hyfil'' carbon-fiber fan assembly was in service on the
Rolls-Royce Conway The Rolls-Royce RB.80 Conway was the first turbofan engine to enter service. Development started at Rolls-Royce in the 1940s, but the design was used only briefly, in the late 1950s and early 1960s, before other turbofan designs replaced it. H ...
s of the
Vickers VC10 The Vickers VC10 is a mid-sized, narrow-body long-range British jet airliner designed and built by Vickers-Armstrongs (Aircraft) Ltd and first flown at Brooklands, Surrey, in 1962. The airliner was designed to operate on long-distance route ...
s operated by
BOAC British Overseas Airways Corporation (BOAC) was the British state-owned airline created in 1939 by the merger of Imperial Airways and British Airways Ltd. It continued operating overseas services throughout World War II. After the passi ...
. Specialist aircraft designers and manufacturers Scaled Composites have made extensive use of CFRP throughout their design range, including the first private crewed spacecraft
Spaceship One SpaceShipOne is an experimental air-launched rocket-powered aircraft with sub-orbital spaceflight capability at speeds of up to 3,000 ft/s (900 m/s, 3240 km/h), using a hybrid rocket motor. The design features a unique "feathering" ...
. CFRP is widely used in micro air vehicles (MAVs) because of its high strength to weight ratio.


Automotive engineering

CFRPs are extensively used in high-end automobile racing. The high cost of carbon fiber is mitigated by the material's unsurpassed strength-to-weight ratio, and low weight is essential for high-performance automobile racing. Race-car manufacturers have also developed methods to give carbon fiber pieces strength in a certain direction, making it strong in a load-bearing direction, but weak in directions where little or no load would be placed on the member. Conversely, manufacturers developed omnidirectional carbon fiber weaves that apply strength in all directions. This type of carbon fiber assembly is most widely used in the "safety cell" monocoque chassis assembly of high-performance race-cars. The first carbon fiber monocoque chassis was introduced in Formula One by
McLaren McLaren Racing Limited is a British motor racing team based at the McLaren Technology Centre in Woking, Surrey, England. McLaren is best known as a Formula One constructor, the second oldest active team, and the second most successful Formula ...
in the 1981 season. It was designed by
John Barnard John Edward Barnard (born 4 May 1946, Wembley, London) is an English engineer and racing car designer. Barnard is credited with the introduction of two new designs into Formula One: the carbon fibre composite chassis first seen in with McLar ...
and was widely copied in the following seasons by other F1 teams due to the extra rigidity provided to the chassis of the cars. Many supercars over the past few decades have incorporated CFRP extensively in their manufacture, using it for their monocoque chassis as well as other components. As far back as 1971, the
Citroën SM The Citroën SM is a high-performance coupé produced by the French manufacturer Citroën from 1970 to 1975. The SM placed third in the 1971 European Car of the Year contest, trailing its stablemate Citroën GS, and won the 1972 ''Motor Trend ...
offered optional lightweight carbon fiber wheels. Use of the material has been more readily adopted by low-volume manufacturers who used it primarily for creating body-panels for some of their high-end cars due to its increased strength and decreased weight compared with the
glass-reinforced polymer Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...
they used for the majority of their products.


Civil engineering

CFRP has become a notable material in structural engineering applications. Studied in an academic context as to its potential benefits in construction, it has also proved itself cost-effective in a number of field applications strengthening concrete, masonry, steel, cast iron, and timber structures. Its use in industry can be either for retrofitting to strengthen an existing structure or as an alternative reinforcing (or pre-stressing) material instead of steel from the outset of a project. Retrofitting has become the increasingly dominant use of the material in civil engineering, and applications include increasing the load capacity of old structures (such as bridges) that were designed to tolerate far lower service loads than they are experiencing today, seismic retrofitting, and repair of damaged structures. Retrofitting is popular in many instances as the cost of replacing the deficient structure can greatly exceed the cost of strengthening using CFRP. Applied to reinforced concrete structures for flexure, CFRP typically has a large impact on strength (doubling or more the strength of the section is not uncommon), but only a moderate increase in stiffness (perhaps a 10% increase). This is because the material used in this application is typically very strong (e.g., 3000 MPa ultimate tensile strength, more than 10 times mild steel) but not particularly stiff (150 to 250 GPa, a little less than steel, is typical). As a consequence, only small cross-sectional areas of the material are used. Small areas of very high strength but moderate stiffness material will significantly increase strength, but not stiffness. CFRP can also be applied to enhance shear strength of reinforced concrete by wrapping fabrics or fibers around the section to be strengthened. Wrapping around sections (such as bridge or building columns) can also enhance the ductility of the section, greatly increasing the resistance to collapse under earthquake loading. Such 'seismic retrofit' is the major application in earthquake-prone areas, since it is much more economic than alternative methods. If a column is circular (or nearly so) an increase in axial capacity is also achieved by wrapping. In this application, the confinement of the CFRP wrap enhances the compressive strength of the concrete. However, although large increases are achieved in the ultimate collapse load, the concrete will crack at only slightly enhanced load, meaning that this application is only occasionally used. Specialist ultra-high modulus CFRP (with tensile modulus of 420 GPa or more) is one of the few practical methods of strengthening cast-iron beams. In typical use, it is bonded to the tensile flange of the section, both increasing the stiffness of the section and lowering the
neutral axis The neutral axis is an axis in the cross section of a beam (a member resisting bending) or shaft along which there are no longitudinal stresses or strains. If the section is symmetric, isotropic and is not curved before a bend occurs, then the ne ...
, thus greatly reducing the maximum tensile stress in the cast iron. In the United States, pre-stressed concrete cylinder pipes (PCCP) account for a vast majority of water transmission mains. Due to their large diameters, failures of PCCP are usually catastrophic and affect large populations. Approximately of PCCP have been installed between 1940 and 2006. Corrosion in the form of hydrogen embrittlement has been blamed for the gradual deterioration of the pre-stressing wires in many PCCP lines. Over the past decade, CFRPs have been used to internally line PCCP, resulting in a fully structural strengthening system. Inside a PCCP line, the CFRP liner acts as a barrier that controls the level of strain experienced by the steel cylinder in the host pipe. The composite liner enables the steel cylinder to perform within its elastic range, to ensure the pipeline's long-term performance is maintained. CFRP liner designs are based on strain compatibility between the liner and host pipe. CFRP is a more costly material than its counterparts in the construction industry, glass fiber-reinforced polymer (GFRP) and aramid fiber-reinforced polymer (AFRP), though CFRP is, in general, regarded as having superior properties. Much research continues to be done on using CFRP both for retrofitting and as an alternative to steel as a reinforcing or pre-stressing material. Cost remains an issue and long-term durability questions still remain. Some are concerned about the brittle nature of CFRP, in contrast to the ductility of steel. Though design codes have been drawn up by institutions such as the American Concrete Institute, there remains some hesitation among the engineering community about implementing these alternative materials. In part, this is due to a lack of standardization and the proprietary nature of the fiber and resin combinations on the market.


Carbon-fiber microelectrodes

Carbon fibers are used for fabrication of carbon-fiber
microelectrode A microelectrode is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue (they were first developed by Ida Hyde in 1921). Pulled glass pipettes with tip diameters o ...
s. In this application typically a single carbon fiber with diameter of 5–7 μm is sealed in a glass capillary. At the tip the capillary is either sealed with epoxy and polished to make carbon-fiber disk microelectrode or the fiber is cut to a length of 75–150 μm to make carbon-fiber cylinder electrode. Carbon-fiber microelectrodes are used either in
amperometry Amperometry in chemistry is detection of ions in a solution based on electric current or changes in electric current. Amperometry is used in electrophysiology to study vesicle release events using a carbon fiber electrode. Unlike patch clamp tec ...
or
fast-scan cyclic voltammetry Fast-scan cyclic voltammetry (FSCV) is cyclic voltammetry with a very high scan rate (up to ). Application of high scan rate allows rapid acquisition of a voltammogram within several milliseconds and ensures high temporal resolution of this elect ...
for detection of biochemical signaling.


Sports goods

CFRP is now widely used in sports equipment such as in squash, tennis, and badminton racquets,
sport kite A sport kite, also commonly known as a stunt kite, is a type of kite that can be maneuvered in the air. A related kite, also controllable and used for recreation, but capable of generating a significant amount of pull and used for providing move ...
spars, high-quality arrow shafts, hockey sticks, fishing rods, surfboards, high end swim fins, and rowing shells. Amputee athletes such as
Jonnie Peacock Jonathan Peacock MBE (born 28 May 1993) is an English sprint runner... An amputee, Peacock won gold at the 2012 Summer Paralympics and 2016 Summer Paralympics, representing Great Britain in the T44 men's 100 metres event. He won a Bronze me ...
use carbon fiber blades for running. It is used as a shank plate in some
basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (appr ...
sneakers to keep the foot stable, usually running the length of the shoe just above the sole and left exposed in some areas, usually in the arch. Controversially, in 2006, cricket bats with a thin carbon-fiber layer on the back were introduced and used in competitive matches by high-profile players including Ricky Ponting and
Michael Hussey Michael Edward Killeen Hussey (born 27 May 1975) is an Australian cricket coach, commentator and former international cricketer, who played all forms of the game. Hussey is also widely known by his nickname 'Mr Cricket'. Hussey was a relative la ...
. The carbon fiber was claimed to merely increase the durability of the bats, but it was banned from all first-class matches by the ICC in 2007. A CFRP
bicycle frame A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles: a main triangle ...
weighs less than one of steel, aluminum, or titanium having the same strength. The type and orientation of the carbon-fiber weave can be designed to maximize stiffness in required directions. Frames can be tuned to address different riding styles: sprint events require stiffer frames while endurance events may require more flexible frames for rider comfort over longer periods. The variety of shapes it can be built into has further increased stiffness and also allowed
aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
tube sections. CFRP
forks In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods eit ...
including suspension fork crowns and steerers, handlebars, seatposts, and crank arms are becoming more common on medium as well as higher-priced bicycles. CFRP
rims RIMS may refer to: Institutions * Rajendra Institute of Medical Sciences, in Ranchi, Jharkhand, India * Rajiv Gandhi Institute of Medical Sciences (disambiguation), various institutes in India * Regional Institute of Medical Sciences, a medical co ...
remain expensive but their stability compared to aluminium reduces the need to re-true a wheel and the reduced mass reduces the moment of inertia of the wheel. CFRP spokes are rare and most carbon wheelsets retain traditional stainless steel spokes. CFRP also appears increasingly in other components such as derailleur parts, brake and shifter levers and bodies, cassette sprocket carriers, suspension linkages, disc brake rotors, pedals, shoe soles, and saddle rails. Although strong and light, impact, over-torquing, or improper installation of CFRP components has resulted in cracking and failures, which may be difficult or impossible to repair.


Other applications

The fire resistance of polymers and thermo-set composites is significantly improved if a thin layer of carbon fibers is moulded near the surface because a dense, compact layer of carbon fibers efficiently reflects heat. CFRP is being used in an increasing number of high-end products that require stiffness and low weight, these include: *Musical instruments, including violin bows; guitar picks, necks (carbon fiber rods), and pick-guards; drum shells; bagpipe chanters; and entire musical instruments such as
Luis and Clark Luis and Clark, or L&C, is a small, family-run company that sells carbon fiber stringed instruments invented and designed by cellist Luis Leguía (Louie) of the Boston Symphony Orchestra. Their line consists of a violin, viola, cello and double ...
's carbon fiber cellos, violas, and violins; and
Blackbird Guitars Blackbird Guitars is a musical instrument company that manufactures acoustic guitars and ukuleles from composite materials, including carbon fiber and ekoa, a flax linen reinforcement fabric in a bio-epoxy matrix. The company has made contributi ...
' acoustic guitars and ukuleles; also audio components such as turntables and loudspeakers. *Firearms use it to replace certain metal, wood, and fiberglass components but many of the internal parts are still limited to metal alloys as current reinforced plastics are unsuitable. *High-performance drone bodies and other radio-controlled vehicle and aircraft components such as helicopter rotor blades. *Lightweight poles such as: tripod legs, tent poles, fishing rods, billiards cues, walking sticks, and high-reach poles such as for window cleaning. *Dentistry, carbon fiber posts are used in restoring root canal treated teeth. *Railed train bogies for passenger service. This reduces the weight by up to 50% compared to metal bogies, which contributes to energy savings. *Laptop shells and other high performance cases. *Carbon woven fabrics. *Archery: carbon fiber arrows and bolts, stock (for crossbows) and riser (for vertical bows), and rail. *As a filament for the 3D fused deposition modeling printing process, carbon fiber-reinforced plastic (polyamide-carbon filament) is used for the production of sturdy but lightweight tools and parts due to its high strength and tear length. *District heating pipe rehabilitation, using CIPP method.


Disposal and recycling

CFRPs have a long service lifetime when protected from the sun. When it is time to decommission CFRPs, they cannot be melted down in air like many metals. When free of vinyl (PVC or polyvinyl chloride) and other halogenated polymers, CFRPs can be thermally decomposed via
thermal depolymerization Thermal depolymerization (TDP) is the process of converting a polymer into a monomer or a mixture of monomers, by predominantly thermal means. It may be catalysed or un-catalysed and is distinct from other forms of depolymerisation which may rely o ...
in an oxygen-free environment. This can be accomplished in a refinery in a one-step process. Capture and reuse of the carbon and monomers is then possible. CFRPs can also be milled or shredded at low temperature to reclaim the carbon fiber; however, this process shortens the fibers dramatically. Just as with downcycled paper, the shortened fibers cause the recycled material to be weaker than the original material. There are still many industrial applications that do not need the strength of full-length carbon fiber reinforcement. For example, chopped reclaimed carbon fiber can be used in consumer electronics, such as laptops. It provides excellent reinforcement of the polymers used even if it lacks the strength-to-weight ratio of an aerospace component.


Carbon nanotube reinforced polymer (CNRP)

In 2009,
Zyvex Technologies Zyvex Technologies (formerly Zyvex Performance Materials, ZPM) is a molecular engineering company headquartered in Columbus, Ohio. Zyvex Technologies focuses on developing advanced materials, including prepreg, epoxy resins, and adhesives. Histo ...
introduced carbon nanotube-reinforced epoxy and carbon pre-pregs.
Carbon nanotube A scanning tunneling microscopy image of a single-walled carbon nanotube Rotating single-walled zigzag carbon nanotube A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers. ''Single-wall carbon nan ...
reinforced polymer (CNRP) is several times stronger and tougher than CFRP and is used in the Lockheed Martin F-35 Lightning II as a structural material for aircraft. CNRP still uses carbon fiber as the primary reinforcement, but the binding matrix is a carbon nanotube-filled epoxy.


See also

* * * * * Forged carbon fiber * Carbon-ceramic


References


External links


Japan Carbon Fiber Manufacturers Association (English)Engineers design composite bracing system for injured Hokie running back Cedric Humes
a 1968 '' Flight'' article on the announcement of carbon fiber
Carbon Fibres – the First Five Years
A 1971 ''Flight'' article on carbon fiber in the aviation field {{DEFAULTSORT:Carbon Fiber-Reinforced Polymer Aerospace materials Allotropes of carbon Composite materials Fibre-reinforced polymers Synthetic fibers