Carbon Fiber That Breaks Through The "King Of New Materials"

 China has realized the localization of carbon fiber of multiple series and levels, solved the problem of independent guarantee of high-performance carbon fiber, and became the third country to master high-performance carbon fiber technology after Japan and the United States

 Domestic carbon fiber breaks through the triple blockade of foreign technology, equipment and products, and achieves the goal of growing out of nothing and getting rid of being under the control of others. We can see the long-term accumulation of China's scientific research strength and industrial strength, as well as the strong advantages of the national system

 Since 2021, carbon fiber enterprises have enjoyed booming business and rising profits, and have been favored by capital and financing. However, in the eyes of many insiders, the carbon fiber industry still has the hidden danger of disordered basic research and industrial development

As a "material man" who has fought with carbon fiber for 36 years, Xu Lianghua is pleased that "carbon fiber has been initially removed from the new material list of" choke "

The professor from the School of Materials Science and Engineering of Beijing University of Chemical Technology and the director of the National Carbon Fiber Engineering Technology Research Center told Outlook Newsweek that China has realized the localization of carbon fiber in multiple series and levels, solved the problem of independent guarantee of high-performance carbon fiber, and became the third country after Japan and the United States to master high-performance carbon fiber technology.

Known as the "king of new materials", carbon fiber is an indispensable strategic new material for national economy and national defense construction. Especially for the manufacturing industry, it is not only a large amount of advanced basic materials that need to be solved, but also a key strategic material that restricts development. The upstream and downstream industrial chains are extremely important for restructuring China's new material industry system.

We can see the long-term accumulation of China's scientific research strength and industrial strength, as well as the strong advantages of the national system, by breaking through the triple blockade of foreign technology, equipment and products and achieving the goal of growing out of nothing and getting rid of being under the control of others.

The story of carbon fiber striving for self-improvement is particularly interesting today when the country emphasizes industrial safety, autonomy and controllability. According to the survey results of the Ministry of Industry and Information Technology on more than 130 key basic materials of more than 30 large enterprises in China in 2018, 32% of key materials are still blank and 52% rely on imports.

How can we keep the banner of technology first flying high with the prosperity of carbon fiber obtained by breaking through iron shoes? How can China's new materials represented by carbon fiber build a better industrial innovation ecology to ensure future industrial security and international competitive advantage?

In the production workshop of Guoxing Carbon Fiber Company of Jilin Chemical Fiber Group, workers tidy up the carbon fiber precursor (photographed on October 31, 2022). Photographed by Yan Linyun

　　 Crossing the "natural cutting" of carbon fiber

In many people's impression, carbon fiber is a kind of material on the "altar" with magical performance and high price.

This kind of fiber material with more than 92% carbon content, which combines the strong tensile strength of carbon materials and the soft processability of textile fiber materials, is made by carbonizing organic fibers such as polyacrylonitrile fiber, viscose fiber, asphalt fiber, etc. at high temperature.

Carbon fiber is as thin as hair and as light as a feather. Its diameter is about 5~7 microns, and a dozen or so hairs together can be as thick as one hair; And the density is only 1/5 of steel, 2/5 of titanium, and 3/5 of aluminum, with lightweight characteristics.

Thin and lightweight carbon fiber, at the same time, as strong as steel. A bunch of standard 12K (1K means that a bunch of carbon fibers contains 1000 precursors) polyacrylonitrile based carbon fibers can withstand about 130 kg. Especially in the oxygen free high temperature of 3000 ℃, other fibers have already turned to ashes, but carbon fibers are safe.

The excellent mechanical properties of carbon fiber, coupled with the ability of corrosion resistance, oxidation resistance, rust resistance and many other materials that are beyond the reach of other materials, are mostly added to resin, metal, ceramics, concrete and other materials as reinforcement materials to form composite materials. It is a worthy new generation of reinforcement fiber king.

The first marketable application of carbon fiber in China was the carbon fiber reinforced resin fishing rod, which was listed in 1972. Since then, the application of carbon fiber has expanded to high-end industrial manufacturing and cutting-edge scientific and technological fields. At present, it has played a major role in aerospace, wind turbine blades, fuel cells, sports and leisure and other broad fields.

According to the size of fiber tow, carbon fiber can be divided into small tow (≤ 24K) and large tow (>24K). Small tow production process is difficult to control and expensive, and is usually used in the fields of national defense, military industry, aerospace. Large tow has low production cost and high cost performance, and is mainly used in industrial and civil fields such as clean energy and construction engineering.

According to Zhu Bo, director of the Institute of Polymer Materials of Shandong University and a senior expert in carbon fiber, Carbon fiber is a kind of material with "talent": "Everyone says that the 21st century is the era of carbon, and carbon fiber is its first responsibility. In a sense, carbon fiber will be one of the important supporting materials for the fourth industrial revolution. In the coming era of interstellar navigation, clean energy and artificial intelligence, carbon fiber and carbon fiber composites will play an increasingly important role."

The development and preparation of carbon fiber with thin appearance and wide use is extremely difficult.

According to Zhu Bo, carbon fiber equipment technology integrates materials science, chemistry, textile science, mechanical automation and other disciplines and is highly interdisciplinary. It is an extremely complex system engineering. From the quality of raw and auxiliary materials to each process of precursor and carbonization, there are a lot of "choke" technologies such as basic research, process and equipment. Take preparation as an example, its process includes hundreds of subdivisions, involving more than 2000 control parameters. Parameter changes at each control point may cause a chain reaction, leading to product quality fluctuations, or even failure.

The quality of precursor determines the performance of carbon fiber. Zhu Bo said that the performance of carbon fiber depends heavily on the microstructure and atomic sequence regularity of the precursor. If there are defects in the molecular structure and aggregation structure of the precursor, the quality and performance of the carbon fiber will be greatly affected.

More strictly, to ensure the stability of precursor performance, it is necessary to ensure the quality of each strand. "Take a bunch of standard 12K carbon fiber as an example, its 12000 wires must be of reliable quality. Only by constantly exploring and testing can we find a relatively scientific and reasonable process combination. Without hard work, we can not make high-performance carbon fiber." Zhu Bo said.

The difficult preparation process makes carbon fiber a "natural barrier" in front of materials scholars. Japan and the United States, which monopolize relevant technologies, have implemented strict patent protection and comprehensive technical blockade on carbon fiber. "Notification of price rise and reward supply" was the reflection of the international carbon fiber market at that time.

China has changed the global carbon fiber pattern under the three blockades of Japan and the United States on carbon fiber technology, equipment and products - in 2005, The CCF-1 grade (equivalent to T300 grade carbon fiber in Toray, Japan, T refers to high-strength carbon fiber, and the higher the figure below means the better the strength) carbon fiber developed by Guangwei Composite Materials (Weihai Guangwei Composite Materials Co., Ltd., a subsidiary of Guangwei Group, hereinafter referred to as Guangwei) has passed the special acceptance of carbon fiber in the National 863 Plan, marking that China has found a successful technical route, It owns its own industrialized carbon fiber for the first time.

Since then, the localization of carbon fiber has made rapid progress and large-scale construction, seeking a "small to large" leap after "from scratch". According to the 2021 Global Carbon Fiber Composite Market Report released by Guangzhou Saiao, the domestic carbon fiber operational capacity in 2021 will be 63400 tons, accounting for 30.5% of the global total capacity of 207600 tons. At the same time, China surpassed the United States for the first time to become the world's largest carbon fiber producer.

China has become the third pole of the global carbon fiber map.

　　 Scientific research to break through key laboratory technologies

Prior to this, the research on carbon fiber in China was unknown and experienced a long period of wandering.

Xu Lianghua came into contact with carbon fiber at the low point of domestic carbon fiber research. "It was 1986, more than ten years since China started the development of PAN based carbon fiber."

PAN based carbon fiber, also called polyacrylonitrile carbon fiber, is the main variety of carbon fiber, and its output accounts for more than 90% of the total carbon fiber.

In Xu Lianghua's view, the development of PAN based carbon fiber in China is basically synchronized with that abroad. It should be said that the gap between the start and the foundation is not thin, but until 2000, the preparation technology of PAN based carbon fiber in China was still persistent, and even the gap with foreign countries is still widening. "However, the market demand for carbon fiber is very urgent, and it is in an awkward situation that it cannot be supplied even though it wants to be used."

Xu Lianghua believes that there are many factors behind the long-term wandering, such as less investment in science and technology, barriers to fragmentation, and insufficient technology accumulation. But the most critical is that the material industry lacks the power to understand carbon fiber from cognition to scientific research, and fails to find the mainstream technology of localization. "At the root, there is a lack of basic research."

Xu Lianghua explained that there was little basic research on carbon fiber in China in the last century. "It is needless to say that enterprises, universities and research institutes also spend most of their energy on solving the engineering problems of enterprises, and pay little attention to the core basic research. It was not until the mid-1990s that people found that there was a problem with simply immersing themselves in technology research and development that they began to return to basic research and go to the foundation."

Taking the preparation of PAN based carbon fiber from precursor as an example, according to Xu Lianghua, at that time, China already had the preparation technology of dimethyl sulfoxide method, but did not play a role in the preparation of carbon fiber in the structural field. "This shows that we have not thoroughly understood the technology. In the end, we have not enough effort, accumulation and skill in basic research."

Xu Lianghua led the team to focus on basic research. "We have done basic research for about two or three years. We regard carbon fiber as a polymer material, return to basic scientific problems, follow the objective laws of polymer materials, and simplify complex problems. Since then, we have found the right direction and developed rapidly," said Xu Lianghua.

In 2000, Xu Lianghua's team successfully broke through the mainstream technology of PAN based carbon fiber precursor technology in China - the new process of dimethyl sulfoxide method. "Although the technology we broke through in the laboratory is a bit rough, it has laid a technical foundation for solving the 'availability' problem of domestic high-performance carbon fibers for structural materials."

　　 Mechanism helps to walk out of the engineering "valley of death"

The engineering research of carbon fiber is put on the agenda after the basic research has reached the dark time.

In the scientific research and innovation chain, there is a crucial engineering link between the laboratory and industrialization of scientific and technological achievements, and efforts are made to solve the problems of obtaining test products through the laboratory process and whether mass production can be achieved.

Among them, the pilot scale test known as "Valley of Death" is the key link of engineering. "There is a saying in the industry that if one problem is solved in the scientific research stage, 10 problems will be solved in the pilot test stage, and 100 problems will be solved in the industrialization stage," said Zhu Bo.

He explained that in scientific research, if a technical problem or theoretical derivation is solved, it can be said to be a breakthrough or even a major breakthrough. In the pilot test, there are many trivial technical problems that need to be solved one by one, and a little carelessness may lead to halfway. "In this link, scientists are often unable to move forward, and entrepreneurs are often unable to move backward. This stage is very difficult and difficult. It often needs the help of national policies and funds. National platform support is crucial."

The difficult path for carbon fiber to get through engineering is closely related to the support of the national "863 Program".

In 2001, Shi Changxu, then an 83 year old strategic scientist and academician of the Chinese Academy of Sciences and the Chinese Academy of Sciences, told the CPC Central Committee to promote the listing of this project as a national "863" project and lead the development of carbon fiber.

In 2002, the national "863 Plan" carbon fiber project was officially launched, with 100 million yuan of research and development funds invested. Since then, NSFC has also provided financial support for carbon fiber. "China's carbon fiber key technology breakthrough has gained momentum from this," said Xu Lianghua.

At that time, Xu Lianghua was also the deputy leader of the special expert group on carbon fiber key technologies set up by the Ministry of Science and Technology. According to him, during the "Tenth Five Year Plan" period, under the leadership of the national "863 Plan" carbon fiber project, China has formed three relatively concentrated research and development bases, namely Beijing University of Chemical Technology, Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences (hereinafter referred to as Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences), and Shandong University, and established several high-level research and development platforms for carbon fiber and composite materials. "The research and development of carbon fiber began to be carried out as a technology system of great synergy, breaking their respective battle situations."

Xu Lianghua was particularly impressed by the changes in the mechanism.

Xu Lianghua said that since the engineering of the first high-performance carbon fiber in 2005, the then Commission of Science, Technology and Industry for National Defense (now the State Administration of Science, Technology and Industry for National Defense) used the one-stop project management process from technology driven to demand driven for the first time.

In the past, material researchers did their research mostly from the research itself. They could finish their work if they could publish articles and patents, and then they could be awarded professional titles, awards and "hats", regardless of scale and engineering, which users care about. Demand traction is different. R&D personnel need to examine the preparation of carbon fiber from the perspective of application, and research and use it.

"This has profoundly changed the thinking and concept of the R&D personnel. Because the development and production of carbon fiber is ultimately for the application of a certain field, and no research into the use is tantamount to white research. When the concept changes, the idea changes greatly. This model is of great significance for demonstration, and since then the key materials in China have also used this model." Xu Lianghua said.

The "863 Plan" carbon fiber project abandoned the views of state-owned and private sectors, and let the evaluation ranking leader undertake the project in a fair competition way, which is a pioneering approach.

Guangwei, a well-known private enterprise in the carbon fiber field, came to the fore.

Lu Zhaojun, chairman of Guangwei Composites, told reporters that Guangwei was a fishing rod manufacturer located in Weihai, Shandong Province. Thanks to the blind sampling method advocated by Shi Changxu, it joined the "national team" of carbon fiber.

Lu Zhaojun said that blind sampling test was a kind of evaluation method that was widely used later. It consisted of a special sampling expert group who went to the site for sampling, and then numbered the samples uniformly and sent them to the designated third-party testing unit for testing. The testing unit did not know the source of the samples. "It is with this new evaluation mode that Guangwei, relying on its excellent product performance, has been ranked in the" 863 Plan "carbon fiber project in the leading evaluation ranking."

Under the national one game project management strategy, we participated in the close cooperation between institutes and enterprises, and successively broke through the PAN based carbon fiber ton test line and 100 ton pilot line.

"This declares that China has broken through the domestic T300 carbon fiber core technology, and China has become one of the few countries in the world that master the key technology of high-performance carbon fiber engineering," Lu Zhaojun said.

China finally has the qualification to be discussed on carbon fiber.

　　 Enterprises strive to break through the dilemma of industrialization

One after another, it is the key battle of improving the output and quality of domestic carbon fiber - industrialization.

Lu Zhaojun said that if the T300 carbon fiber produced in 2005 was compared to a car, it would be Xiali at most, which could drive but could not compare with BMW. What's more, there are many cars from Xiali to BMW, including Volkswagen, and there are also many models of high-performance carbon fiber. "It's not easy to make better products. Every upgrade of high-performance carbon fiber products involves the breakthrough of key technologies and key equipment."

Taking the QZ5526 of Guangwei benchmarking Toray T800 carbon fiber as an example, its preparation difficulty is a big step higher than that of GQ3522. "Without mentioning the process technology, Guangwei invested hundreds of millions of yuan in the research and development of the carbonization furnace necessary for the preparation of QZ5526, which lasted for three years." Lu Zhaojun introduced.

More important than technical pressure is financial pressure.

Talking about "burning money", Lu Zhaojun has lingering fears: "Every day when a thousand ton production line starts, millions of dollars will be lost. Without any effect, money will be wasted. Tens of millions of equipment will be useless if they say they can't use it, and they can only sell scrap iron. Even Chen Guangwei, the founder of Guangwei, once said that what tests the entrepreneur's nerves most is not how much money he has invested at once, but when he has invested huge amounts of money continuously, he has not seen the output, But still continue to burn money every day. "

The huge capital investment and long return cycle have nearly broken the capital chain of Guangwei. "By 2012, the bank had refused to lend money to Guangwei. In order to research and develop high-performance carbon fiber, Guangwei not only spent years of accumulation, but also mortgaged all the plants, equipment and even orders for fishing gear production before financing." Lu Zhaojun said.

Guangwei's carbon fiber research and development process is not an isolated case. Famous entrepreneurs in the carbon fiber field, such as Zhang Guoliang of Zhongfu Shenying and Qian Yunbao of Hengbao, have suffered a lot from tackling carbon fiber problems, and some of them have almost exhausted their family assets.

Fortunately, through the hard work of domestic industrial forces, China has finally built an industrial base for the industrial application of carbon fiber, formed a number of enterprises that can survive and develop in the market, and to a considerable extent, has achieved comprehensive and systematic localization, most of the technology has entered a higher level of independent research and development and positive design.

The price of international carbon fiber has collapsed: from 2009 to 2014, the price of T700, an industrial carbon fiber, dropped to 1/3 of the original price, and the price of high-performance carbon fiber dropped to 1/10 of the previous price.

China FAW Group Co., Ltd. and China Aerospace Science and Technology Group Co., Ltd. jointly developed a domestic snowmobile with high-strength carbon fiber body. The picture shows FAW R&D domestic snowmobile workshop (taken on January 20, 2022) Zhang Jian

　　 Study the double hidden worries of speed reduction and industrial disorder

Since 2021, carbon fiber enterprises have enjoyed booming business and rising profits, as well as capital and financing.

However, in the eyes of many insiders, the carbon fiber industry still has the hidden danger of disordered basic research and industrial development.

China has become the world's largest carbon fiber production country, but in the high-performance carbon fiber market, Japan accounts for nearly 50% of the world's output. In terms of product quality, China has been able to produce T700, T800, T1000 and other high-performance products, but commercial mass production is not much.

This means that China's carbon fiber has no problems in industrialization and scale, but there is still a gap between China and international industry giants in terms of cost and quality stability. It is urgent to continue to make efforts in technology, capital, and talent to achieve stable quality and cost reduction.

Xu Lianghua said: "The cost of domestic carbon fiber is relatively high. The high cost is not only an economic problem, but also an in-depth lack of technological development. For example, the production capacity has not been released, the equipment technology is not up to standard, the proportion of sizing agent is high, and the fiber qualification rate is low. High quality and low cost can be achieved through reasonable technical means. We propose to strive to achieve the price of carbon fiber by 2030 10 US dollars/kg. To achieve this goal, we still need to do a lot of technical work. "

In recent years, the "good time" of carbon fiber is making some enterprises slow down their efforts in the past. "Many enterprises are still using the preparation methods of more than 10 years ago, and their willingness and awareness of technology upgrading are not strong. It can even be said that when the carbon fiber business was not so good a few years ago, enterprises were still more or less able to concentrate on research. The past two years have been easier, but technology research and development has stopped." Xu Lianghua said.

What worries Xu Lianghua even more is that "even now, our basic research strength of carbon fiber cannot catch up with the international technology leading enterprises, and even the strength to engage in complete key technology research is still shrinking."

Zhu Bo also felt that there were fewer experts in the same industry in recent years. In his view, the space for carbon fiber technology progress is still very large, far from the "ceiling". "On the one hand, carbon fiber requires a lot of money. On the other hand, the right people and teams should be selected. In particular, the accumulation and potential, team structure and talent echelon should be considered for rolling and phased assessment."

The disordered development of carbon fiber industry has also attracted the attention of experts interviewed.

Zhang Shouchun, a researcher of Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences and head of the carbon fiber team, told reporters that under the current heat, carbon fiber has seen some low-level repeated construction, which is not conducive to the improvement of the overall level of the industry. "Domestic carbon fiber enterprises still have shortcomings in core technology, product advantages, industrial chain layout, intellectual property protection, etc. In the future, facing full market competition, especially in the case of competition with world-class carbon fiber enterprises, there may be insufficient comprehensive strength and competitiveness."

Lu Zhaojun said that after 2010, local governments were very enthusiastic about carbon fiber, and private enterprises were also very popular. Domestic carbon fiber production lines were built in a large scale. At most, there were more than 40 carbon fiber enterprises nationwide. Now the number of enterprises is greatly reduced, but it is still crowded. "Carbon fiber is a strategic new material, which needs national strategic layout."

Xu Lianghua believes that China's carbon fiber industry does not have enough competitiveness. "The application fields of carbon fiber and its composites are all established in western countries, and China has no original innovative application fields. Only when we develop a symbolic carbon fiber application market that is not available in foreign countries, can the industry be truly competitive."

In this sense, several interviewed experts suggested that they should solve the forward-looking systematic problems in a down-to-earth manner, "practitioners should ask themselves, once imported carbon fiber can enter unimpeded, will the existing customers of the enterprise lose their customers? Can our technology still occupy a place? Is the safety of the industrial chain in their own hands?"

(Note: This article only represents the author's own opinion, and has nothing to do with this website)

(Article | Zhang Ranran, reporter of Outlook Newsweek)

(Source: China Chemical Fiber Industry Association)