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  12/3/2013 Carbon-fiber-reinforced polymer - Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/Carbon-fibre_reinforced_plastic 1/9 Tail of an RChelicopter, madeof CFRP Carbon-fiber-reinforced polymer From Wikipedia, the free encyclopedia  (Redirected from Carbon-fibre reinforced plastic) Carbon-fiber-reinforced polymer , carbon-fiber-reinforced plastic  or carbon-fiberreinforced thermoplastic  ( CFR P , CRP , CFRTP  or often simply carbon fiber , or even carbon ), is an extremely strong and light fiber-reinforced polymer which contains carbonfibers.The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester or nylon, are sometimes used. Thecomposite may contain other fibers, such as aramid e.g. Kevlar, Twaron, aluminium, or glass fibers, as well as carbon fiber. The properties of the final CFRP product can also beaffected by the type of additives introduced to the binding matrix (the resin). The mostfrequent additive is silica, but other additives such as rubber and carbon nanotubes can beused. CFRPs are commonly used in the transportation industry; normally in cars, boats andtrains, and in sporting goods industry for manufacture of bicycles, bicycle components,golfing equipment and fishing rods.Although carbon fiber can be relatively expensive, it has many ap plications in aerospace and automotive fields, such as Formula One racing. The compound is also used in sailboats,rowing shells, modern bicycles, and motorcycles because of its high strength-to-weight ratio and very good rigidity. Improved manuf acturing techniques are reducing the costs and time to manufacture, making it increasingly common in small consumer goods as well, such ascertain ThinkPads since the 600 series, tripods, fishing rods, hockey sticks, paintballequipment, archery equipment, tent poles, racquet frames, stringed instrument bodies, drum shells, golf clubs,helmets used as a paragliding accessory and pool/billiards/snooker cues.The material is also referred to as  graphite-reinforced polymer   or  graphite fiber-reinforced polymer   ( GFRP   isless common, as it clashes with glass-(fiber)-r einforced polymer ). In product advertisements, it is sometimes refer red to simply as  graphite  fiber   for  short. Contents 1 Properties2 Manufacture2.1 Molding2.2 Vacuum bagging2.3 Compression molding2.4 Filament winding3 Application3.1 Aerospace engineering3.2 Automotive engineering3.3 Civil engineering3.4 Carbon fiber microelectrodes  12/3/2013 Carbon-fiber-reinforced polymer - Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/Carbon-fibre_reinforced_plastic 2/9 Carbon fiber reinforced polymer  3.5 Sports goods3.6 Other applications4 Disposal and recycling5 Carbon nano-tube reinforced polymer (CNRP)6 See also7 References8 External links Properties Carbon-fiber-reinforced polymers are composite materials. In this case the composite consists of two parts; amatrix and a reinforcement. In CFRP the reinforcement is carbon fiber, which provides the strength. The matrix isusually a polymer resin, such as epoxy, to bind the reinforcements together. [1]  Because CFRP consists of twodistinct elements, the material properties depend on these two elements.The reinforcement will give the CFRP its strength and rigidity; measured by Stress (mechanics) and Elastic modulusrespectively. Unlike isotropic 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. [2] Despite its high initial strength-to-weight ratio, a design limitation of CFRP is its lack of a definable fatigueendurance 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 endurance limits, the complex failure modes of compositesmeans that the fatigue failure properties of CFRP are difficult to predict and design for. Consequently, when usingCFRP for critical cyclic-loading applications, engineers may need to design in considerable strength safety marginsto provide suitable component reliability over its service life. Manufacture The primary element of CFRP is a fiber. From these fibers, aunidirectional 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 carbon-fiber-reinforced polymer is made varies, depending on the piece being created,the finish (outside gloss) required, and how many of this particular pieceare going to be produced. In addition, the choice of matrix can have a profound effect on the properties of the finished composite.Many carbon-fiber-reinforced polymer parts are created with a singlelayer of carbon fabric that is backed with fiberglass. A tool called achopper gun is used to quickly create these composite parts. Once a thin shell is created out of carbon fiber, thechopper gun cuts rolls of fiberglass into short lengths and sprays resin at the same time, so that the fiberglass andresin 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:  12/3/2013 Carbon-fiber-reinforced polymer - Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/Carbon-fibre_reinforced_plastic 3/9 Molding One method of producing graphite-epoxy parts is by layering sheets of carbon fiber cloth into a mold in the shapeof 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 partis very corrosion-resistant, stiff, and strong for its weight. Parts used in less critical areas are manufactured bydraping 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-cured, because evensmall 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. Afiberglass, carbon fiber or aluminum mold is polished and waxed, and has a release agent applied before the fabricand resin are applied, and the vacuum is pulled and set aside to allow the piece to cure (harden). There are twoways 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 laidin the mold and placed in the bag. The other one is done by infusion, where the dry fabric and mold are placedinside 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 thatrequires holes inside the bag. Both of these methods of applying resin require hand work to spread the resin evenlyfor 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 isalready impregnated with resin (pre-preg) and is applied to the mold in a similar fashion to adhesive film. Theassembly is then placed in a vacuum to cure. The dry layup method has the least amount of resin waste and canachieve lighter constructions than wet layup. Also, because larger amounts of resin are more difficult to bleed outwith wet layup methods, pre-preg parts generally have fewer pinholes. Pinhole elimination with minimal resinamounts generally require the use of autoclave pressures to purge the residual gases out. Compression molding A quicker method uses a compression mold. This is a two-piece (male and female) mold usually made out of fiberglass or aluminum that is bolted together with the fabric and resin between the two. The benefit is that, once it is bolted together, it is relatively clean and can be moved around or stored without a vacuum until after curing.However, the molds require a lot of material to hold together through many uses under that pressure. Filament winding For difficult or convoluted shapes, a filament winder can be used to make CFRP parts by winding filaments arounda mandrel or a core. Application Applications for CFRP include the following:  12/3/2013 Carbon-fiber-reinforced polymer - Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/Carbon-fibre_reinforced_plastic 4/9 Airbus A350, 53% compositematerialsHoneycomb structure made of Carbon-fiber-reinforced polymer on aBMW i3 Aerospace engineering The Airbus A350 is built of 53% CFRP [3]  including wing and fuselagecomponents, the Boeing 787 Dreamliner, 50%. Specialist aircraftdesigner and manufacturer Scaled Composites have made extensive useof CFRP throughout their design range including the first privatespacecraft Spaceship One.CFRP is widely used in micro air vehicles (MAVs) because of its highstrength to weight ratio. In the MAVSTAR Project(http://www.robotics.unsw.edu.au/mavstar/), CFRP reduces the weightof the MAV significantly and the high stiffness of the CFRP bladesovercome the problem of collision between blades under strong wind.Ultralight aircraft (see SSDR) such as the E-Go, rely heavily on CFRP in order to meet the category weightcompliance requirement of less than 115 kg (254 lb) without pilot or fuel. Automotive engineering Carbon-fiber-reinforced polymer is used extensively in high-endautomobile racing. [4]  The high cost of carbon fiber is mitigated by thematerial's unsurpassed strength-to-weight ratio, and low weight isessential for high-performance automobile racing. Race-car manufacturers have also developed methods to give carbon fiber piecesstrength 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 themember. Conversely, manufacturers developed omnidirectional carbonfiber weaves that apply strength in all directions. This type of carbon fiber assembly is most widely used in the safety cell monocoque chassisassembly of high-performance race-cars.Many supercars over the past few decades have incorporated CFRPextensively in their manufacture, using it for their monocoque chassis as well as other components.Cast vinyl has also been used in automotive applications for aesthetics, as well as heat and abrasion resistance.Most top-of-the-line cast vinyl materials such as 3M's DiNoc (interior use) and SI's Si-1000 3D (exterior use)have lifespans of 10+ years when installed correctly.Until recently, the material has had limited use in mass-produced cars because of the expense involved in terms of materials, equipment, and the relatively limited pool of individuals with expertise in working with it. Recently, severalmainstream vehicle manufacturers have started to use CFRP in everyday road cars.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 theglass-reinforced polymer they used for the majority of their products.
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