reinforced plastic - Carbon fiber

Carbon fiber reinforced plastic (CFRP or CRP) is a very strong, light and expensive composite material or fiber reinforced plastic. Similar to glass reinforced plastic, which is sometimes simply called fiberglass, the composite material is commonly known by the name of its reinforcing fibers (carbon fiber). Plastic is most often epoxy, but other plastics such as polyester, vinyl ester or nylon, are also sometimes used. Some compounds contain carbon fiber and glass fiber reinforcement. Less commonly, graphite-reinforced plastic term is also used.

Many applications in aerospace and automotive fields, as well as in sailboats, and particularly in modern bikes, where these qualities are important. It is increasingly common in small consumer products, as well as laptops, tripods, fishing rods, frames of racquet sports, stringed instrument bodies, classical guitar strings, and drum shells.


Compound

The choice of matrix can have a profound effect on the properties of the finished product compound. A common plastic for this application is epoxy, and materials produced with this methodology are often referred to generically as compounds. A way to produce pieces of graphite epoxy layers of cloth carbon fiber cloth in a mold to form the final product. The alignment and weave of the fibers of the fabric is carefully chosen to maximize the strength and stiffness properties of the resulting material. In the most demanding applications all air is evacuated from the mold, but in applications where cost is more important than structural rigidity, this step is omitted. The mold is filled with epoxy and is heated or air cured. The resulting rigid group does not corrode in water and is very strong, especially for its weight. If the mold contains air, small air bubbles will be present in the material, reducing strength. Most composite parts are manufactured by draping cloth over a mold, either pre-impregnated with epoxy resin in the fibers (also known as prepreg), or "painted" on it. Hobby or cosmetic parts are often made in this way, as well as high performance aerospace components. High performance parts molds are often vacuum bagged and / or autoclaved.

The large number of (often manual) work required for the manufacture of composite materials has so far limited their use in applications requiring a large number of complicated parts.

The chemistry and manufacturing techniques such as epoxy thermosetting plastics are often unsuitable for mass production. A potential savings and improved performance as is to replace the epoxy matrix with a thermoplastic material such as nylon or polyketone. Boeing's entry in the Joint Strike Fighter competition included a carbon fiber wing delta-shaped reinforced thermoplastics, but the difficulties in making this part contributed to Lockheed Martin won the competition.

Process

The process in which most of CFRP is varied, depending on the piece being created, the finish (not glossy) is necessary, and how many of this particular piece will be produced.

For simple pieces that relatively few copies are needed (1-2 per day) a vacuum bag can be used. A fiberglass or aluminum mold is polished, waxed, and has a release agent applied before the fabric and resin applied and the vacuum is pulled and set aside to allow the piece to cure (harden). There are two ways to apply the resin into the cloth into a vacuum mold. One is called a wet tray, where two-part resin is mixed and applied before being placed in the mold and placed in the bag. The other is a resin induction system, where you place the dry fabric and mold in the bag, while the vacuum pulls the resin through a tube into the bag, then through a tube with holes or something similar to the resin evenly distributed throughout the tissue. Wire loom works perfectly for a tube that requires holes in the bag. Both methods require the application of resin to work hand to spread the resin evenly for a glossy finish, with tiny pinholes. A third method of construction of composite materials is known as a dry pan. In this case, the carbon fiber material is already impregnated with resin (pre-preg) and applied to the mold in a manner similar to the adhesive film. The assembly is then placed in a vacuum to cure. The dry tray method has the least amount of resin waste and can achieve lighter constructions than wet tray. In addition, due to greater amounts of resin are more difficult to bleed out tray methods wet prepreg parts generally have fewer imperfections. pin removal resin minimum quantities usually require the use of autoclave pressure to flush out the waste gases.

A quicker method uses a compression mold. This is a two-piece (male and female) mold usually made of fiberglass or aluminum which is screwed together with the fabric and resin between them. The benefit is that, once bolted together, is relatively clean and can be transferred or stored without a vacuum until after curing. However, molds require a lot of material to hold together through many uses under that pressure.

Many carbon fiber parts are created with a single layer of carbon fabric and filled with fiberglass. A chopper gun can be used to quickly create these pieces. Once a thin layer is created from carbon fiber, the chopper gun is a pneumatic tool that cuts a roll of fiberglass and resin spray at the same time, so the fiberglass and the resin is mixed on the spot. The resin is either external mix, where the hardener and resin sprayed separately, or internal, blending the inside, which requires cleaning after each use.

In ways difficult or impossible (like a tube) a filament winder can be used to make parts.

Automotive uses

CFRP is widely used in motor racing, especially in Formula One and IndyCar racing. The high cost of carbon fiber is mitigated by the relationship of material unsurpassed strength-to-weight and low weight is essential for racing high performance cars. Racecar manufacturers have also developed methods to make carbon fiber pieces strength in a particular direction, so it is strong in a load direction, but weak in directions that little or no load is placed on the member. Conversely, manufacturers developed omnidirectional carbon fiber fabrics to use force in all directions. This type of carbon fiber assembly is the most widely used in the safety cell "monocoque chassis mount race cars high performance.

Several supercars over the past few decades have incorporated CFRP extensively in their manufacture, they use for their monocoque chassis and other components. Examples include the Koenigsegg CCR, Koenigsegg CCX, McLaren F1, Mercedes McLaren SLR, Bugatti Veyron, Bugatti EB110, Pagani Zonda, Ferrari Enzo and Porsche Carrera GT.

Until recently, the material has had limited use in mass production of cars because the expense involved in terms of materials, equipment, and the relatively small number of people with experience of working with him. Recently, several mainstream vehicle manufacturers such as General Motors and BMW have started to use carbon fiber technology in road cars every day.

Chevrolet is using carbon fiber in a special version of its flagship sports, the Corvette. The Z06, a special high performance version of the Corvette, including carbon fiber body weight forward and increase the rigidity of the body instead of glass reinforced plastic found in the standard Corvette.

BMW produces carbon fiber reinforced plastic in its plant in Landshut. To make the roof of the BMW M3 CSL, for example, five layers of carbon fiber cloth are placed in a press of 1,800 tons, which is epoxy resin transfer molding and heat-cured in a robot-automated process. The resulting roof is half the weight of an equivalent steel roof.

The use of the material has been more readily adopted by low volume manufacturers like TVR who use it primarily for creating body panels for some of its high-end cars because of their greater strength and reduced weight compared with plastic reinforced glass used for most of their products.

Often street racers or fans tuners will purchase a carbon fiber hood, spoiler or body panel as part of the market for accessories for your vehicle. However, these pieces are rarely made of full carbon fiber. They are often just a single layer of carbon fiber laminated fiberglass for the "look" of CF. It is common for these parts to remain unpainted to accentuate the look of carbon fiber fabric.

Civil engineering applications

CFRP has recently become something of a hot topic in the field of structural engineering, surprisingly, for reasons of cost-effectiveness. For example, many old bridges in the world were designed to tolerate much lower service loads than they are today subject to, and compared with the cost of replacing the bridge, reinforcing it with CFRP is quite cheap. Due to the incredible stiffness of carbon fiber, which can be used under stretches to help prevent excessive deflections, or wrapped around the beams to limit shear stresses. Since 2005, the Westgate Bridge in Melbourne, is the world's largest bridge to be strengthened with carbon fiber laminates [1].

Much research is being done now with CFRP as reinforcement within concrete structures such as beams and bridge decks. The material has many advantages over conventional steel, especially that it is much more rigid and resistant to corrosion. There are, however, some doubts among the engineering community about implementing these new materials until a more real world has been made.

Other applications

One area where CFRP has found a good use in the manufacture of bicycles, especially high-end racing bikes. The vibration absorption properties of CFRP do to have a less severe travel, while providing weight reduction compared to traditional bike tube materials such as aluminum or steel. The choice of tissue can be carefully selected to maximize stiffness. The exploitation of the variety of forms can be constructed in CFRP has further increased rigidity and aerodynamic considerations also allowed in the profiles of the tube. carbon fiber frames, forks, handlebars, seatposts and crank arms are becoming common in the middle-and higher-priced bikes. CFRP holders are used in most of the new racing bike.

Another widespread use of carbon fiber is in the manufacture of fishing rods. Its high flexibility and low weight make it ideal to feel every bite.

Most modern rowing shells are made of carbon fiber, which significantly reduces the weight of the boat.

A system for resin transfer molding has been developed by Wilson Benesch advanced composite structures can be created. This manufacturing technology creates the most rigid and lightweight speaker cabinet. The damping properties are exceptional, do not give the same vibration similar to that absorbs the skills are in high-performance cycles. The combination of these properties makes it possible to achieve the lowest possible sound out of the cabinet. No distortion of the cabinet by a more accurate transducer.

Recycling

A major concern is the use of full life cycle of materials such as carbon fiber reinforced plastics have an almost infinite life. Some companies [2] are succeeding in the recycling of carbon fiber. The strategy focuses on the recycling of milling, compounding or shredding recycled carbon fiber, and the use of search for the final product in several industrial applications (including carbon fiber applications less stringent than those required by , say, the aerospace industry). It is also commonly used in electronics such as laptops, to reduce total weight and improve durability.

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