Carbon fiber: Lightweight applications are a breakthrough

China Coatings Online News:
: Lightweight Applications or Breakthroughs. Carbon fiber has been from the laboratory to widely used, the global demand for carbon fiber is growing, domestic carbon fiber is still lagging behind, the country from the "12th Five-Year Plan" began to develop carbon fiber and other new materials as the country's strategic industry development. With the support of national policies and local governments, many carbon fiber projects have landed. The further expansion of the application demand for carbon fiber may focus on the three main areas of "air and land wind": aerospace; Upstream carbon fiber production focuses on Zhongfu Condor, Jiangsu Hengseng, Jiangsu Aviation Department, midstream carbon fiber pre-immersion materials and composite materials production focus on Kandexin, Haiyuan machinery, Zhongfulian, downstream carbon fiber end products focus on medium fu carbon core, Far East cable. There is only one new three-plate carbon fiber listed company: Hengseng shares, with the further growth of the carbon fiber market, future earnings can be expected. Carbon fiber: typical of new materials moving from laboratory to widely used. Why is carbon fiber so popular? - Light, strong, good stability. Carbon fiber is an inororated polymer fiber with a carbon content of more than 90%. Its strength is bigger than steel, density is smaller than aluminum, more resistant to corrosion than stainless steel, and can conduct electricity like copper, is a valuable electrical, thermal and mechanical properties of a new material, known as "black gold." Carbon fiber is "in the same family" as graphene, the most recent star material, and it can be said that carbon fiber is formed by the accumulation of countless tiny graphene sheets (nanoscales) in a certain orientation.
also explains why carbon fiber and graphene have many similar electrical, thermal, and electrical properties. What are the classifications of carbon fiber? - Mainly three categories: manufacturing raw materials, fiber quantity, performance. The carbon fiber family is large, a variety of carbon fiber has different characteristics, so there are a variety of classification. PAN-based fiber is the mainstream of the market according to the classification of raw materials for the manufacture of carbon fiber. Carbon fiber is mainly divided into polypropylene acrylic (PAN) carbon fiber, asphalt-based carbon fiber, viscose-based (cellulose)) carbon fiber. PAN-based carbon fiber. Because PAN-based fiber preparation method is relatively simple, the product is very excellent anti-bending performance, so it is the mainstream of the carbon fiber market, accounting for more than 90%. According to the number of fibers, large silk / small silk applications vary, small silk bundles are expensive. A single carbon fiber is not up to the needs of the application in mechanical strength. The carbon fiber actually used is made up of several carbon fiber wire clusters. 1K represents 1000 wires in a bundle of carbon fiber. Usually 1K, 3K, 6K, 12K and 24K carbon fiber is called small wire bundle carbon fiber, small silk beam carbon fiber is mainly used in the military, aviation field, so it is also known as "space grade" carbon fiber. The price is more expensive than the carbon fiber of the large wire bundle. Carbon fiber above 36K is called large wire bundle carbon fiber, including 48K, 60K, 120K, 180K, 360K and 480K. Large wire bundle carbon fiber is mainly used in automobiles, wind installations, general industry and other fields, so it is called "industrial grade" carbon fiber.
are classified according to the performance of the force, T and M are different. Generally speaking, carbon fiber is divided into high-strength carbon fiber, high-mode carbon fiber, ultra-high-strength carbon fiber, ultra-high-mode carbon fiber. The so-called high strength, refers to the higher stretch strength. The greater the stretch strength, the harder it is for carbon fiber to be pulled off. High mold, refers to the higher the extruded module, the greater the stretching module, the more rigid carbon fiber, "prefer not to bend." But in practice, we usually use the carbon fiber world leader - Toray, Japan's product number, such as T300, T800, T1000, M55, etc. to correspond to different properties of carbon fiber. Because these models were originally divided according to the strength of Toray, so carbon fiber strength T300T600T700T800T1000, module M30M40M46M50M60M65. What is the technology gap between China and foreign countries? High-performance carbon fiber to Japanese enterprises as the benchmark, the domestic is still at the T300/ T700 level. At present, high-strength, high-mould carbon fiber is basically monopolized by Japanese and American enterprises. The reason is that carbon fiber preparation process is complex, process parameters need a lot of energy and money exploration, easy to form a monopoly. Domestic is still at the T300, T700 level, higher quality carbon fiber still can not be mass production. Carbon fiber preparation process and production equipment greatly affect the quality of carbon fiber: carbon fiber preparation process is complex, involving more process parameters, the accumulation of these parameters often take several years cycle. And carbon fiber production equipment technical barriers are high, foreign leading enterprises on the production equipment to implement a blockade and ban sales. This is also the root cause of the current high-performance carbon fiber production in China is difficult to achieve.
The current mainstream carbon fiber is PAN-based carbon fiber, so this paper takes PAN-based carbon fiber as an example to introduce the preparation process of carbon fiber: acrylonitrile single system preparation, acrylonitrile is the bulk of basic organic chemical raw materials, mainly through the acrylic oxidation process, is an important monomer for the preparation of polypropylene fiber. Its purity and quality directly affect the quality of synthetic carbon fiber filaments. The polymerization reaction forms polypropylene acrylic, and the production of polypropylene acrylic by acrylonitrile monomer polymerization is an extremely important step. The speed of polymerization reaction process, distribution of raw materials in reactor, reaction temperature control, etc. all affect the quality of polypropylene acrylic. The polypropylene acrylic wire is formed by wire spraying technology, the polypropylene acrylic is dissolved in the solvent, and then the mixture of polypropylene acrylic and solvent is sprayed out through a shower-like spray wire head to form polypropylene acrylic raw wire. During the re-production process, traction is applied to the front end of the original wire to fineen and dense the original wire. In this process, solvent selection and traction size and traction speed are important process parameters. And the accuracy of process parameters is closely related to the production equipment. Pre-oxidizing raw silk forms pre-oxygen filament, for raw silk - polypropylene acrylic fiber, because it is a one-dimensional linear large molecular chain, so the difficulty of heat is poor. It can be converted into a large molecular chain of a two-dimensional trapezoidal structure through a pre-oxidation process (200 to 300 degrees C) in order to withstand subsequent higher temperature treatment. An important equipment is involved here - pre-oxidation furnaces. Temperature gradient control of pre-oxidation furnace, air exhaust control and traction control of raw wire are all important factors that affect the quality of carbon fiber in the pre-oxidation process.
the pre-oxygen filament has been carbonized or further graphiteized, and the preliminary carbon fiber has been obtained. The so-called carbonization process is to let pre-oxidized PAN fibers crack at high temperatures, escaping hydrogen, oxygen, nitrogen and other small molecules, and finally leave behind the process of carbon. The temperature is usually between 1000 and 2000 degrees Celsius. The carbon atoms inside the resulting carbon fiber are arranged in a disorderly arrangement. Neither the strength nor the mod is optimal. Therefore, according to the needs of the product, the subsequent can also increase the graphite process. Graphiteization is a process in which carbon atoms inside a carbon material are rearranged at higher temperatures (2000 to 3000 degrees C) and slowly move towards a perfect six-way mesh. The strength and mould of carbon fiber are significantly increased at this time. Preoxidation technology and graphiteization technology is the key step in the preparation of high-performance carbon fiber, the quality of domestic pre-oxidation furnaces and graphite chemical furnaces and foreign advanced level gap is large, in the pre-oxidation and graphiteization link to break through the barrier of production technology and production equipment is an important direction of china's carbon fiber development. For carbon fiber surface treatment. PAN fibers that go through the carbonization process or graphiteization process have become carbon fibers. But this carbon fiber is not the end product needed. Usually carbon fiber is composited with resin, metal, ceramic and other substations to form a variety of carbon fiber composite materials. Carbon fiber composites are the materials needed for industry, aerospace, automotive and other fields. By simple analogy, carbon fiber is like steel, and the substation is like cement, and the combination of steel and cement is the building material of a house.
and the surface treatment of carbon fiber is to increase the surface area of fiber, enhance the chemical activity of fiber surface, so that the subsequent substation and carbon fiber can be closely combined, the quality of the binding interface directly affects the performance of carbon fiber composite materials. Carbon fiber pulp treatment, in the production process due to mechanical friction, carbon fiber surface easy hair, or the appearance of single wire break phenomenon, which will affect the strength of carbon fiber. In addition, the appearance of wool also affects the binding of carbon fiber to the substation. Therefore, on the surface of carbon fiber will be coated with another layer of organic protection layer, reduce the phenomenon of carbon fiber hair break. To obtain carbon fiber processing into carbon fiber composite materials, such as the carbon fiber mentioned above will not directly enter the field of application, but the use of resin, metal, ceramics and other materials as a substation and its composite, the formation of strength, mod and other comprehensive indicators qualified structural materials, that is, carbon fiber composite materials. According to
China Coatings Onlineexperts
, the most widely used and most widely used resin-based composite materials (CFRP), people are also constantly exploring carbon fiber processing into CFRP methods, such as resin transfer molding (RTM), injection molding, tensile molding, etc. , not much to introduce here. Carbon fiber market is huge, mainly optimistic about the "air and land wind", the global carbon fiber production capacity continues to improve, with carbon fiber in large aircraft, wind power, automotive industry and other fields of expanding demand, the world's major carbon fiber production enterprises have expanded the scale of production. Global carbon fiber production capacity was approximately 12.9 million tons in 2014, an increase of 11% over 2013. At a growth rate of 10%, the global carbon fiber production capacity reached 141,900 tons in 2015.
, Japan's Tori Corporation, as a leader in the carbon fiber industry, is expected to have a production capacity of 21.1 thousand tons, accounting for 13.6% of global production capacity. Domestic carbon fiber production enterprises in fuse Eagle, Jiangsu Hengseng production capacity is about 4000 tons. Even from a capacity perspective, there is still a big gap between Chinese companies and Japan and the U.S. Japanese and U.S. companies have an absolute advantage in market share, from the market share point of view, the global carbon fiber market demand in 2014 53.5 thousand tons, accounting for about 41% of the total capacity. Carbon fiber demand is forecast to grow by about 10%, reaching 59,000 tonnes in 2015. At present, the vast majority of the market share by the United States and Japanese companies divided. In the small silk beam market, three Japanese companies, Tori, Dongbang and Mitsubishi, accounted for 54% of the market, followed by Hexcel in the United States, Taiwan Ando Plastics and so on. In the big silk beam market, Hexcel of the United States and SGL of the United States accounted for 73% of the global share, the dominant position. Domestic carbon fiber has been completed from nothing to have, rapid development. With the increasing support of national policies and the increasing market demand, China's carbon fiber technology and industrialization level has improved significantly. Breakthroughs from nothing have been achieved in the past 20 years. At present, the domestic large and small carbon fiber production enterprises nearly 40, the total production capacity of domestic carbon fiber reached 15,000 tons. Among them, T300-grade carbon fiber performance has reached the international level, has entered the stage of industrialization development, T700-class carbon fiber has been built a thousand tons of production line, products into the application assessment stage, low-cost dry-spray textile T700-class carbon fiber has achieved large-scale production, T800-grade carbon fiber ton line built and achieved mass production. However, the preparation technology of high-grade carbon fiber with high mold and high strength still has a big gap with the international carbon fiber enterprises.
strong support for the policy, carbon fiber is popular. The Government of Japan has vigorously promoted the sustainable development of the Carbon Fiber Industry Alliance. China's carbon fiber development is not too late, but unfortunately, from the mid-1970s after nearly 40 years of development, China's carbon fiber industry is still unable to compete with Japanese companies in the market. One reason is Japan's strong policy support. The Japanese government attaches great importance to the research and development of high-performance PAN-based carbon fiber-related technologies and gives strong human and financial support, including basic policies such as the Basic Plan for Energy, the Outline of Economic Growth Strategy and the Kyoto Protocol and the Energy Saving Technology Research and Development Program. The second is the establishment of industrial alliances. Japan's leading position in the field of carbon fiber is closely related to the Japan Carbon Fiber Industry Alliance. Japan earlier formed an industry alliance, the alliance members cover the entire carbon fiber industry chain, forming a common advantage within the alliance, speed up the development of carbon fiber technology, for the development and commercialization of technology to provide a better environment. Domestic carbon fiber national key support, will accelerate development. From the beginning of the 12th Five-Year Plan, the country has made the development of new materials such as carbon fiber a strategic development of the country. With the support of national policies and local governments, many carbon fiber projects have landed. Recently, the "13th Five-Year Plan" is about to be launched, carbon fiber materials are highly likely to be included. During the 13th Five-Year Plan period, the independent innovation ability of enterprises, high-performance carbon fiber production equipment and preparation process is still the direction of national key support, but also the direction of domestic carbon fiber enterprises need to focus on the key. Carbon fiber application prospects: the most optimistic about the "air and land wind." In the 1960s and 1970s, carbon fiber came out of the lab and had a small number of applications in military fields such as rockets and spacecraft, when it was expensive to prepare and there was little downstream demand, much like the current graphene industry. With the deepening of research and the reduction of preparation costs, carbon fiber is gradually applied to sports equipment and other fields.
the end of the 20th century, carbon fiber began to be used in aircraft and automobile manufacturing on a large scale, greatly promoting the maturity and development of the carbon fiber industry. Today, global carbon fiber production exceeds 50,000 tons, with an average cost of less than $5 per pound. Global sales of carbon fiber will grow from $1.6 billion in 2011 to $4.5 billion in 2020, and carbon fiber composites will grow from $16.1 billion in 2011 to $48.7 billion in 2020, according to AJR Consultants. Carbon fiber and composite materials first entered the civilian field is sports and leisure supplies. The main applications are bicycles, fishing rods, golf clubs and tennis rackets and other sporting goods. According to research, the global sports and leisure market demand for carbon fiber accounted for 16% of the total demand, but this part of the demand is close to saturation. This proportion is expected to fall to 5 per cent by 2020. Aerospace's already industrial applications will account for more than 95% of the demand. Among the industrial demand, it is expected that the automotive and fan blades will grow significantly, driving the development of the global carbon fiber industry. High-performance carbon fiber gradually entered the field of civil aviation, with the rising international oil prices, as well as aircraft flight time and reliability of higher requirements, carbon fiber gradually into the field of aircraft structural materials, challenging the unified position of aluminum alloy. It is reported that for every kilogram of weight lost in commercial aircraft, they can save $3,000 a year in fuel. Long-range rockets and spacecraft can save $10,000 in fuel for every kilogram they lose. Statistics show that the current use of carbon fiber composite materials in small commercial aircraft and helicopters has been 70 to 80%, in military aircraft accounted for 30 to 40%, in large passenger aircraft accounted for 10 to 50%. According to 2014 CCeV statistics, the aerospace market requires 29% of the carbon fiber, but the total market amount is 48%, indicating that the sector is mostly high-value carbon fiber.
airbus's A380