What is carbon fiber? - Carbon fibers are among the strongest and lightest materials marketed today. Carbon fibers are a polymer, sometimes called ‘graphite fibers’. Carbon fibers are 5 times stronger and 2 times harder than steel but they are lighter than steel thus being the perfect manufacturing material for numerous components. These are only a few of the reasons carbon is preferred by engineers and designers.
Carbon fiber is very thin filaments, finer than human hair. These filaments are bundled together in carbon material, usually coming in tows of 3k, 6k и 12k. Then, if necessary to permanently shape them, carbon fibers can be set on a mould and covered with resin or plastic.
Carbon fabric is sold in various weaves of different strength grades. The most common ones are the plain weave, harness satin weave, twill weave and unidirectional.
There are two reasons for carbon fabric weave to be so important: appearance and functionality. Each fabric looks quite different and sometimes people prefer the appearance of a specific fabric for certain purposes. The weave also defines the strength of the product. The unidirectional weave makes for a sheet of carbon fibers very strong along the fibers but weak in the opposite direction. On the other hand, the plain and twill weave have uniform strength since they are strongest in the points where filaments cross in both directions.
Advantages of carbon fiber
● High rigidity and durability – carbon fibers are of higher fatigue resistance compared to metal which means that carbon fiber components will not wear out quickly when in constant use. Carbon fiber is of lower vibration properties than steel.
● Great tensile strength – carbon is one of the strongest reinforcing fibers on the market when it comes to tension. It is very difficult to stretch or bend carbon fibers.
● It is characterized by low weight and high rigidity – carbon fibers are of low density with very high rigidity to weight ration.
● High corrosion resistance – when combined with suitable resins, carbon fibers make for one of the most corrosion resistant materials.
● High thermal resistance.
● Low coefficient of thermal expansion.
• Resistant to UV rays - carbon fibers can be resistant to UV rays when combined with appropriate resins.
• X-Ray permeable - carbon fibers are transparent for radiation and invisible to X-rays which makes them irreplaceable in medical equipment.
• Electrical conductivity - carbon fibers composite materials are excellent electric conductors.
Disadvantages of carbon fiber
• Carbon fibers will break when compressed, or pressured above their resistance level, or exposed to great impact. Carbon will break under a hammer-hit. Processing and punching can also weaken some areas thus increasing the likelihood of damage.
• Relative price – carbon is an expensive high-quality material. The price of raw material has dropped over the last five years, but demand has not increased sufficiently to promote supply. This results in keeping the prices at the same level for the foreseeable future.
• High level of technical equipment and qualification – Working with carbon fibers requires a high level of qualification, equipment and complex methods for production of high-quality composite materials (e.g. rigid carbon sheets, laminated sandwich panels of carbon fibers and composites, carbon tubes, etc.)