Application of Carbon Fiber Functionalization

 

The biggest feature of carbon fiber is its high specific strength, which means it is light in weight and strong in strength. Most carbon fiber composite materials use this property of carbon fiber. In composite materials, carbon fiber is compounded with plastic, ceramic, metal or even carbon matrix. The matrix material plays the role of transferring load in the composite material, which transfers the external force to the carbon fiber.

 

Carbon fiber plays the role of bearing load in the composite material, so the destruction of the composite material must first break the carbon fiber. This is our common carbon fiber composite material. In addition to its high specific strength, carbon fiber also has the properties of high temperature resistance, corrosion resistance, soft and easy to weave, small thermal expansion coefficient, and easy conductivity. Although the application of these properties of carbon fiber is not as good as that of structural materials, it has also formed certain special products.

 

 

As A Thermal Insulation Material

Isn’t carbon fiber a high thermal conductivity? How can it be used as a thermal insulation material? This starts with the way heat is transferred. There are three ways of heat transfer: heat transfer, convection, and thermal radiation.

 

Heat transfer is the contact between objects of different temperatures, and heat is transferred from the high temperature object to the low temperature object.

 

Convection Is The Transfer Of Heat Through Fluid Flow.

Thermal radiation is the transfer of heat to another object in the form of radiation waves. Carbon fiber is needled into felt, which becomes a loose and porous carbon fiber polymer. The shape of the felt is maintained by friction between the fibers. The fibers are overlapped together, which is a point contact, which greatly reduces the heat transferred through the solid heat transfer path. When the temperature is above 800℃, as the radiation intensity increases, thermal radiation becomes the main form of heat transfer.

 

The radiation wave is constantly reflected between the fibers and dissipated inside the felt, thereby achieving the effect of heat insulation. At present, carbon fiber used as thermal insulation material is also divided into three types: viscose-based, polyacrylonitrile-based, and asphalt-based. Polyacrylonitrile-based raw materials are cheap and the production process is simple. Many domestic companies are using this type of carbon felt. However, after high-temperature treatment, the fibers of this type of carbon felt are brittle and prone to broken fiber scraps, which is harmful to the furnace environment and human health. Therefore, foreign companies rarely use polyacrylonitrile-based carbon felt.

 

Viscose-based carbon fiber is not easy to graphitize during high-temperature treatment, so the heat transferred through the solid is very small. Under the same conditions, the thermal insulation effect is also the best of the three materials. However, the carbon yield in the production process of viscose-based carbon fiber is relatively low, and even 10 kg of raw silk can produce 1 kg of viscose-based carbon fiber, so additives are needed to increase the carbon yield, which will produce residues of other elements. However, many companies can now achieve high purity.

 

Asphalt-based carbon fiber is easy to graphitize, so the purity can be improved very well.

 

 

Carbon Fiber Sealing Material

Packing is usually woven from softer threads, usually with a square or rectangular or round cross-sectional area, and filled in the sealing cavity to achieve sealing. In some corrosive or high-temperature environments, carbon fiber packing has its own advantages. It mainly uses carbon fiber’s no creep, good fatigue resistance, small thermal expansion coefficient, good corrosion resistance, and good thermal conductivity. It is mainly used in high temperature, high pressure and wear-resistant working conditions.

 

Carbon Fiber Heating Materials

Carbon fiber heating materials utilize the electrical conductivity and thermal radiation properties of carbon fiber. Currently, floor heating and bathroom heaters based on the concept of carbon fiber are very popular, and are also a hot spot for the use of carbon fiber. Carbon fiber heating materials have the advantages of long life, high thermal efficiency, and good radiation waves for the body. The most important thing is that the thermal radiation waves emitted by carbon fiber will not cause moisture loss in the skin while heating the body, and there is no dry feeling on the skin after using traditional bathroom heaters.

 

 

Carbon Fiber Powder Conductive Material

This type of material is widely used, but its characteristic is to use the conductive properties of carbon fiber. The carbon fiber is cut and ground to obtain cylindrical particles of equal length. It retains many excellent properties of carbon fiber, and has a small shape, pure surface, large specific surface area, and is easy to be wetted by resin and dispersed.

 

In composite materials, carbon fiber is compounded with plastic, ceramic, metal and even carbon matrix. The matrix material plays the role of transferring load in the composite material, which transfers external force to the carbon fiber. The carbon fiber plays the role of bearing load in the composite material, so the destruction of the composite material must first break the carbon fiber.

 

This is our common carbon fiber composite material. In addition to high specific strength, carbon fiber also has high temperature resistance, corrosion resistance, soft and easy to weave, small thermal expansion coefficient, and easy conductivity. Although the application of these properties of carbon fiber is not as good as structural materials, it has also formed certain special products.