Carbon fiber out of the low-end road to break through

A few days ago, Jiangsu Lianyungang Condor Bicycle Co., Ltd. produced a 6-kilogram carbon fiber bicycle with its own intellectual property rights, and its main raw material carbon fiber was provided by Zhongfu Shenying Carbon Fiber Co., Ltd. This bicycle has passed the European carbon fiber bicycle quality certification, the price is only 1/3 of the imported carbon fiber bike of the same type. The company's annual production of 100,000 carbon fiber bicycles will begin construction within the first phase of the project. Compared with ordinary materials bikes, carbon fiber bicycles are lightweight, durable, and save physical strength. As a bicycle body material, this is just a small example of carbon fiber applications.

Carbon fiber is getting closer and closer to our daily life. This fibrous carbon material is 100 times thinner than hair, and its density is less than 1/4 of steel, but its tensile strength is 7-9 times that of steel. Pull elasticity is also higher than steel, carbon fiber is lighter than aluminum, harder than steel. Due to its light weight, the quality of carbon fiber composites is about 20% of that of steel, and depending on fiber grade and orientation, it can even achieve strength similar to that of steel. In addition, the carbon fiber does not rust, and the use of carbon fiber material can significantly reduce the weight of the product, which can significantly improve the fuel efficiency. The airplanes and automobiles produced by it can save a lot of fuel.

Due to its high strength, high modulus, high temperature resistance, corrosion resistance, electrical conductivity, and thermal conductivity, carbon fiber makes it a new chemical material with both carbon material's strong tensile strength and fiber softness and processability. It is a new generation of reinforcing fibers. At present, carbon fiber is not only widely used in aerospace and military industries, but also has huge application space in the fields of automobile components, wind power blades, nuclear power, oil field drilling, sporting goods, carbon fiber composite core cables, and building reinforcing materials.

Dilemma one:

Production technology lags far behind developed countries

As carbon fiber applications involve the national defense and military industry, carbon fiber technology and production equipment are strictly confidential in all countries. Japan, the United States and other major production companies have long been not only high-performance special raw silk preparation technology is highly confidential, not willing to transfer, nor sell high-performance special original silk products, and the possibility of introduction of complete sets of technology is also very small.

According to He Fu, a researcher at the Shanxi Coal Chemistry Research Institute of the Chinese Academy of Sciences, China's T300 general-level industrialization has made breakthrough progress. 100-ton and 1,000-ton carbon fiber have been put into production; T700 grade is undergoing pilot scale-up, and T800 is being developed in the laboratory. . At present, the product quality of one or two units in China has exceeded the performance index of T300 grade, reached the level of T400, and can be produced in small batches. This is the level of carbon fiber research and development that Toray Corporation of Japan made in the 1980s. Judging from the overall situation, China is currently in the transition period from the T300 general level to the high-performance T700 and T800.

However, due to different application areas, the quality requirements for carbon fiber and its composite materials are also different. In other words, only the general-purpose T300 is far from meeting market demand. Therefore, He Fu believes that high-performance T700, T800, and T1000 carbon fibers must be developed. He cited the use of T800H grades and their composite materials P2302 (T800H/3902-2) as primary structural materials for the manufacture of large aircraft, and T700S grades for the manufacture of carbon fiber composite cored aluminum-stranded cables (ACCC). Therefore, the development of high-performance carbon fiber is a top priority. The leading products in the future should be T700 and T800 grades, and the T700 grade will gradually replace the T300 grade and become a new generation of general-purpose carbon fiber.

Dilemma II:

Small-scale, multiple-repetition research and development

It is not too late for China to start research on carbon fiber. Although some progress has been made, it has been developing slowly over the years. According to Qian Bozhang, the founder of Jinqiu Energy and Chemical Engineering Studio of Shanghai Qingruo Information Technology Co., Ltd., China began the research of PAN-based carbon fiber in the 1960s by the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, and completed the continuous process in the early 1970s. Test equipment. Later, the Shanghai Synthetic Fiber Research Institute, the Shanxi Coal Chemical Institute of the Chinese Academy of Sciences, the Beijing University of Chemical Technology, and the Shandong University of Technology started their research work. They passed the pilot test in the mid-1980s and entered the trial production stage of industrialization. Hundred kilograms to several tons of small test equipment and annual production of tens of tons of pilot plant. However, in general, there is a big gap between the advanced level of technology, production capacity and product quality.

Since the beginning of the 21st century, the domestic carbon fiber industry has developed rapidly. Anhui Huarong Carbon Fiber Co., Ltd. took the lead in introducing a production facility with an annual output of 500 tons of raw silk and 200 tons of PAN-based carbon fiber, which successfully filled the gap in the industrial production of China's carbon fiber and raw silk industries.

Since 2000, China’s carbon fiber technology has diversified and it has abandoned the original nitric acid precursor yarn manufacturing technology. The successful one-step wet spinning technique using dimethyl sulfoxide as a solvent has been successful. At present, a small number of domestic carbon fiber products developed using independent technologies have reached the level of international products of the same type.

According to Qian Bozhang, in recent years, the relevant national ministries and commissions have taken the industrialization process of carbon fiber technology as a strategic task of our country. Subsequently, some companies have joined the ranks of carbon fiber production. At present, China has produced Jilin Shenzhou Carbon Fiber Co., Ltd., Shandong Tiantai New Material Co., Ltd., Zhejiang Jiaxing Zhongbao Carbon Fiber Co., Ltd., Baoding Swan Chemical Fiber Group, Dalian Xingke Carbon Fiber Co., Ltd., and Shanxi Hengtian Textile New Fiber Technology Co., Ltd., etc. Carbon fiber manufacturers of different sizes have a total annual production capacity of 2,310 tons. According to incomplete statistics, there are currently 11 carbon fiber production companies under construction or under construction. The total production capacity is 7,100 tons of raw silk and 1,560 tons of carbon fiber, of which 4 are under construction. The total production capacity is the annual output of raw silk. 1100 tons, 470 tons of carbon fiber.

In contrast, due to the complexity of carbon fiber production technology, there are no more than 12 companies in the world. They are Japan's Toray, Toho and Mitsubishi Rayon, USA's Cytec, Hexcel, Zoltek, Amoco, Germany. SGL, Korea Taiguang Industry Corporation and Taiwan Plastics Corporation of Taiwan. Among the leading manufacturers are Japan's Mitsubishi Rayon, Toho and Toray, and US Cytec, Hexcel and others.

In 2008, China's comprehensive launch of large-scale aircraft major projects and supporting projects included many chemical and new materials projects including carbon fiber. With the increase in demand for carbon fiber products in all areas represented by this project, many carbon fiber Research projects or 1,000-ton industrialization projects have started. However, as China's carbon fiber industry lacks core industrialization technology with independent intellectual property rights, industrial development will not happen overnight, but development opportunities have already arrived.

According to reports, it is more difficult to transfer technology from research and development to industrialization. Therefore, it is still a long process for carbon fiber to be truly domesticated. Due to the market shortage, "carbon fiber fever" has emerged in China in recent years. However, it should be pointed out that although there is a large demand for carbon fiber products in the domestic market, there is a great risk in blind development. The market surplus will become inevitable after the implementation of these 1,000-ton projects.

According to the prediction of related departments, the demand for carbon fiber in the world will increase at an annual rate of approximately 13%. In 2010, the global demand for PAN-based carbon fiber will reach 50,000 tons, and by 2012 it will reach 60,000 tons. It is expected that the demand will reach 2018. Will reach 100,000 tons.

To this end, the seven global carbon fiber manufacturers (Toray, Toho, Mitsubishi Rayon, SGL, Hexcel, Cytec, and Zoltek) have announced plans to expand production by 78% in the next 3-5 years, with a total investment of 879.70 million euros. Experts estimate that in the short-term, carbon fiber will be in short supply, but by 2012, supply may exceed demand.

One way to break through:

Clenched fists to form a resultant force

How to rapidly increase the pace of upgrading of China's carbon fiber industry in the perspective of supply exceeding demand? Qian Bozhang believes that among the many factors constraining the development of carbon fiber in China, the backwardness of the PAN precursor level is a bottleneck restricting the improvement of the production level of carbon fiber, affecting not only the quality of carbon fiber but also its output, production cost, and market competitiveness.

At present, China urgently needs to master the production technology of high-performance PAN-based yarns and seize market opportunities. Under the premise of perfecting carbon fiber production technology, as soon as possible, breakthroughs will be made in the PAN-based raw wire manufacturing process technology, and high-quality upstream product production lines will be developed to ensure stable carbon fiber production and high-quality products, thereby breaking the foreign blockade and monopoly on key technologies.

To this end, major scientific research institutions and enterprises should clench their fists to form a concerted effort to avoid repeated introductions and repeated research, avoid detours and save costs.

Qian Bozhang suggested that the state's support should mainly focus on establishing a systematic research network for interconnection, and at the same time increase investment and taxation, credit, and other policy inclinations to encourage carbon fiber production enterprises, raw material production companies, and powerful investment companies. In particular, the financial strength of pioneering companies is tilting. Although China has a clear plan and objectives for the production of carbon fiber, the phenomenon of repeated introduction and repeated research is still very serious. The state should focus on supporting several successful companies, vigorously coordinate, optimize the layout, integrate resources, and work together to prevent low-level redundant construction and blind development, and achieve the goal of allowing more companies to avoid detours and save costs. Make our country a country that independently controls, owns technology, and achieves industrialized development.

Qian Bozhang also suggested that we should learn from advanced foreign experience, strengthen the close integration of production, education and research, and establish related mechanisms to raise the development of high-performance fiber industry to the national strategic height, so that China's carbon fiber industry can develop rapidly and healthily.

Breaking the road two:

Focus on recycling

In recent years, foreign research on carbon fiber technology development has focused on improving performance and reducing costs. Japan Toray Corporation has decided to phase out T300 carbon fiber based on the advanced composite material market development, focusing on the development of carbon fiber products with a tensile strength of 4,000 to 5,000 MPa and a price comparable to that of T300. At the same time, due to the high cost performance of large tow carbon fiber, Also began to develop large tow carbon fiber, such as the newly developed T6005, T7005, T700G and so on.

In addition, some companies attach importance to the development of environmentally friendly carbon fiber recycling. Japan's Toray, Teijin and Mitsubishi Rayon plan to jointly produce large-scale recycled carbon fiber to promote the recycling of high-strength lightweight materials.

Carbon fiber products are used in special fields and their service life and refresh cycle are strictly required. A large number of discarded carbon fiber products are in urgent need of treatment. According to Japan's Mitsubishi Rayon estimates, the current global carbon fiber scrap is about 10,000 tons, up to 20,000 tons in 2010. With the expansion of carbon fiber production capacity and the increased use of reinforced materials, environmental friendly trends require companies to pay attention to the recycling of carbon fiber. Developed countries have begun this work: a new process developed by TITK Research Institute in Germany can obtain carbon fiber with a length of ≥20mm and a typical length of 30mm to 70mm from waste carbon fiber textiles without using a torn-cut process; the INASMET transport safety agency in Spain adopts it. Chemical and pyrolysis treatment technologies have developed a new approach for the recycling of carbon fiber-epoxy resin composites. The recycled products can be used for general carbon fiber products.

Japan Toray, Teijin and Mitsubishi Rayon established a joint venture in 2009 to recover and recycle used carbon fiber from aircraft and other equipment. The annual output of recycled carbon fiber will increase from the first few hundred tons to the current world's largest production of 1,000 tons.

At present, in the aspect of recycling of carbon fiber, should our country adopt advanced concepts from abroad and incorporate it into the scope of research and development? After all, standing on the shoulders of giants can make us look higher and further.