Carbon fiber
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Carbon fibre can refer to carbon filament thread, or to felt or woven cloth made from carbon filaments. By extension, it is also used informally to mean any composite material made with carbon filament: for more on that application, see graphite-reinforced plastic. Aside from structural uses, carbon fiber cloth can be used in air filtration and as a high-surface area, corrosion-proof electrode.
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Synthesis
Each carbon filament is made out of long, thin sheets of carbon similar to graphite. A common method of making carbon filaments is the oxidation and thermal pyrolysis of polyacrylonitrile (PAN), a polymer used in the creation of many synthetic materials. Like all polymers, polyacrylonitrile molecules are long chains, which are aligned in the process of drawing fibres. When heated in the correct fashion, these chains bond side-to-side, forming narrow graphene sheets which eventually merge to form a single, jelly roll-shaped filament. The result is usually 93-95% carbon. Lower-quality fiber can be manufactured using pitch or rayon as the precursor instead of PAN.
Textile
These filaments are stranded into a thread. Carbon fiber thread is rated by the number of filaments per thread, in thousands. 3K (3,000 filament) carbon fiber is 3 times as strong as 1K carbon fiber, but is also 3 times as heavy. This thread can then be used to weave a carbon fiber cloth. The appearance of this cloth generally depends on the size of thread and the weave chosen. Carbon fiber is naturally a glossy black, but recently colored carbon fiber has become available.
Uses
Normal civilian uses include (but are not limited to) nearly every type of high-performance vehicle, such as boats, cars, motorcycles, sailplanes etc. Expensive civilian, and military uses include some planes/jets, "plastic" tanks (sometimes made with fiber-glass), and portable floating cubes (used for bridges).
An area where carbon fibre has found good use is in the manufacture of bicycles, especially road bikes. The vibration absorbing properties of carbon smooth out the road, whilst offering improved weight over an aluminium design. The choice of weave can be chosen so as to maximise stiffness. Expolitation of the variety of shapes carbon can be built into has further increased stiffness and also allowed aerodynamic considerations into tube profiles. Carbon frames, forks, handlebars, seatposts and crank arms are all common place on a professional bike. Carbon forks are used on most road bikes.
Process
The process in which most carbon fiber is made varies, depending on the piece being created, the finish (outside gloss) required, and how many of this particular piece are going to be produced.
For simple pieces that relatively few copies are needed of (1-2 per day) a vacuum bagcan be used. A fiberglass, or aluminum mold is polished, waxed, and has a release agent 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 two ways to apply the resin to the fabric in a vacuum mold. One is a wet layup, where the 2 part resin is mixed and applied before being laid in the mold and placed in the bag. The other is a resin induction system, 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 spread the resin throughout the fabric fairly evenly. Wire lume works perfect for your tube that requires holes inside the bag. Both of those methods of applying resin require hand work to spread the resin evenly for a glossy finish, without pin-holes.
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. 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 types of parts. Once a thin shell is created out of carbon fiber, the chopper gun is a pneumatic tool that cuts fiberglass from a roll, and sprays resin at the same time, the fiberglass and resin are mixed on spot. The resin is either extenal mix, where the hardener and resin are sprayed separately, or internal, where they are mixed internally, which requires cleaning ever every use.
For difficult or impossible shapes (such as a tube) a filament winder can be used to make pieces. Filament Winder