On June 21, the 2019 China Chemical Fiber Science and Technology Conference was co-sponsored by the Ministry of Environment and Textile Engineering of the Chinese Academy of Engineering, the China Chemical Fiber Industry Association and the China Textile Engineering Society, supported by the Quanzhou Municipal Government, the Chemical Fiber Professional Committee of the China Textile Engineering Society, the relevant professional committee of the China Chemical Fiber Association and its branch. Quanzhou, Fujian Province. With the theme of "Science and Technology Drive, Fusion Development, Sharing the Future", the conference is committed to disseminating the latest technological achievements and cutting-edge technologies in the upstream and downstream of the chemical fibre industry chain, stimulating the innovative vitality of chemical fibre science and technology talents, promoting the high-quality development of the chemical fibre industry and accelerating the process of building a strong textile country. From government agencies, industry associations, experts, scholars, research backbone, enterprise representatives and colleagues concerned about textile and chemical fibers and related fields, a total of 500 people participated in the forum.
At 9 a.m., as the most cutting-edge part of the conference, the High-level Forum on Advanced Composites and Lightweight Materials Applications took the lead.
▲ Jiang Shicheng, Academician of the Chinese Academy of Engineering
In his speech, Jiang Shicheng, academician of the Chinese Academy of Engineering, pointed out that fibre materials have become one of the fastest and most active fields of science and technology in the world. Scientific and technological innovation in the field of advanced fibre materials is promoting the subversive development of the fibre industry and promoting the establishment of a new generation of fibre industry system. In 2018, China's chemical fibre output reached 50 million tons, accounting for more than 70% of the world's total chemical fibre output, and the position of the chemical fibre industry as a powerful country has initially emerged. Among them, great progress has been made in the research and development of new fiber materials, especially high-tech fibers, and the gap between them and the advanced level of developed countries has been narrowed considerably.
In recent years, through a series of industrial development plans, China has further defined the objectives and tasks of the development of key basic materials industry, providing direction for the continuous promotion of the upgrading of product structure, industrial structure and technological structure of the chemical fiber industry, in order to achieve the scientific development and high-quality development of the chemical fiber industry. In terms of high performance fiber materials, we focus on the development of high performance carbon fibers, para-aramid fibers, ultra-high molecular weight polyethylene fibers, polyimide fibers, silicon carbide fibers and other products. At the same time, we should integrate the superior resources of the new material industry, encourage upstream and downstream enterprises to jointly tackle key problems, and concentrate on breaking through the industrial application of core technologies.
▲ Lv Gang, Vice Mayor of Quanzhou People's Government
Lv Gang, deputy mayor of the Quanzhou Municipal People's government, said in his speech that in recent years, Quanzhou has actively promoted the "China made 2025" pilot demonstration city, the National Independent Innovation Demonstration Zone, and the national innovative city construction, and actively promoted the work of "numerical control generation" and "Internet +", so as to promote the transformation of the textile and chemical fiber industry. Upgrade, formulate the implementation of textile shoes and clothing industry transformation and upgrading roadmap, aiming at the established objectives and tasks, make up for shortcomings, make up for shortcomings, strengthen, and precisely promote the healthy development of the whole industry. In 2018, there were 1179 textile and apparel enterprises, 616 enterprises with annual output value exceeding 100 million yuan, accounting for 91.7% of the total planned output value. The added value of the planned enterprises was 75.932 billion yuan, an increase of 10.6%, accounting for half of the textile and apparel industry in the province. It is an important production base and export base of textile and apparel in China.
How can carbon fibers help lightweight vehicles?
▲Xu Jifeng, Deputy Designer of Beijing Civil Aircraft Technology Research Center of China Commercial Airlines
Composite materials have high specific strength, specific stiffness, strong designability, and can increase fuel efficiency by 20%. Fatigue resistance and corrosion resistance can improve structural efficiency. They have been widely used in civil aircraft. Their application demand in the main structure of civil aircraft leads the trend of research and development of aviation composite materials, and can improve aircraft fuel efficiency. Safety, economy, comfort and environmental protection make the research of composite materials and other new materials more and more important.
However, the anisotropy and brittleness of composite structures make them significantly different from conventional metal materials in load deformation, damage mechanism and failure mode. Xu Jifeng, Deputy designer of Beijing Civil Aircraft Technology Research Center of China Commercial Airlines, said that the anisotropic mechanical properties of the composite itself made the design and analysis difficult. Compared with traditional metal structures, the application of composite materials in aircraft poses new technical challenges and brings a series of key technologies to be broken through, such as connection analysis, stability, damage tolerance, crashworthiness, large openings, lightning protection, fire and fire resistance, anti-deicing, interlayer analysis, etc.
Therefore, he believes that the future aircraft design will adopt breakthrough fuselage and propulsion technology to reduce aerodynamic drag and save fuel; pay attention to improving quiet, environmental protection and comfort; fly at supersonic and supersonic speeds, the high temperature effect of the structure is obvious. This requires integrated structural design based on advanced materials, such as functional composites, which require lighter, more durable and more high temperature resistance. With the improvement of computer performance, comprehensive optimization of overall, aerodynamic, structural and material in the same framework will be achieved.
▲Ding Sansansan, Deputy Engineer of China National Railway Qingdao Sifang Locomotive and Rolling Stock Co., Ltd.
At present, high-speed rail is facing two major difficulties, one is to ensure safety, which is to solve the impact, improve fatigue and corrosion resistance. Second, to improve efficiency, the same car pulls more passengers and makes the car lighter, which requires a lightweight solution.
Ding Sansan, Deputy Engineer of China Railway Qingdao Sifang Locomotive and Rolling Stock Co., Ltd., pointed out that the future development of railway vehicles is to pursue high speed, high efficiency, green and intelligent, and to develop high-speed maglev with speed of 600 km/h, 400 km/h, upper and double-deck EMUs, all of which need lighter and stronger materials. In a word, the comprehensive solution with lightweight as the core is the foundation of future technology. We should focus on solving the contradiction with strength, stiffness, fatigue, corrosion, noise and fire protection, and seek balance-structure optimization, material optimization and integrated optimization. At the same time, efficiency should be mentioned to cope with the increasing prominence of traditional structures and materials. Bottleneck, materials need to be lightweight, impact reduction, load lifting, high weather resistance, high reliability, high availability, long life, less maintenance. This will provide a rare opportunity for the application and promotion of CFRP technology.
Based on this, he suggested that the industry authorities should strengthen the promotion and coordination of CFRP composite industry, promote the relevant enterprises and institutions in an orderly manner, improve their survival and development capabilities, actively strive for the national project of high-speed railway CFRP application technology, and strive for the early establishment of relevant standard research, vehicle development and demonstration projects. He believes that CFRP composite can solve many technical problems faced by high-speed trains with its advantages of lightweight, high strength, corrosion resistance and high temperature resistance. After long-term scientific exploration, it will overcome various technical and economic difficulties and be widely used.
Compared with traditional body materials, carbon fiber reinforced composites have excellent mechanical properties, flexible structure design and good corrosion resistance. They are widely used in automotive field, such as body, chassis, interior, exterior and power system. At present, the main application models of carbon fiber are BMW I3/I8, Mercedes-Benz SLK200 carbon fiber Limited edition, General Corvette, Ford GT2016, Audi Q6e-TRON and so on.
Xiong Fei, general manager of Suzhou Huate Carbon Fiber Co., Ltd., believes that the application of carbon fibre products in automobiles has six advantages: first, lightweight body, low carbon fibre density, 50% weight loss compared with low carbon steel, 30% weight loss compared with magnesium/aluminium alloy structure; second, high integration, free modeling, strong design, streamlined and curved surface. The cost is low, which can reduce the types of parts and the investment of tools; the third is to overturn the production process, replace stamping and welding with die pressing and bonding technology, and save the investment of production line and die and fixture; the fourth is the good reliability of automobiles, high fatigue strength of carbon fibers (up to 70% - 80% of the design load), which can greatly improve the reliability of automobiles; the fifth is automobiles. Good comfort and higher vibration damping can significantly improve the overall noise reduction effect and comfort of the vehicle. Sixth, the vehicle has high safety, the center of gravity of the vehicle decreases after weight reduction, and the operation stability is improved. The energy absorption capacity of the collision is 6-7 times that of steel and 3-4 times that of aluminium.
Based on this, he introduced in detail the selection of carbon fiber materials, product design and process technology, including material selection, process manufacturing, post-processing costs and so on. It is worth mentioning that structural optimization of carbon fiber materials and products can be carried out from four aspects: size optimization, shape optimization, topology optimization and morphology optimization.
▲Chen Pingsheng, Executive Chairman of International Automotive Lightweight Green Technology Alliance
Facing increasingly severe fuel consumption regulations, automobile companies around the world are taking active measures to promote energy saving and emission reduction of automobile products. Taking fuel-fired automobiles as an example, by lightening the weight of the whole vehicle, the fuel consumption can be reduced by 6%-8%, the emission can be reduced by 10%, the braking distance can be reduced by 5%, the acceleration time can be reduced by 8%, and the acceleration time can be reduced by 8%. The tire life is increased by 7%, the fatigue life is significantly improved, and the safety performance of the whole vehicle can be improved.
The global automobile lightweight market will reach 717.2 billion in 2018, and the global automobile lightweight market is expected to reach 124.16 billion by 2020. Over the next three years, China's automotive lightweight market will reach 500 billion yuan, of which 35 billion are new energy vehicles. Then, what is the way to realize the lightweight technology of new energy vehicles? Chen Pingsheng, executive director of the International Alliance of Automobile Lightweight and Green Science and Technology, believes that it is necessary to integrate safer, more energy-saving, more environmentally friendly and intelligent manufacturing modularization, through optimization of component structure design and CAE simulation analysis, high-strength lightweight materials and advanced manufacturing technology. The technology is applied quantitatively to realize the lightweight of mass-produced vehicles. In addition, he also introduced several application cases of advanced composites in new energy mass production vehicles, and pointed out that low-cost carbon fiber composites will be ushered in the field of automotive structural parts industrialization through the establishment of carbon fiber composites technology safety evaluation system, common technology platform and product line cooperative innovation development mechanism. Broad market development prospects.
What are the applications of carbon fibers in energy, manufacturing and other fields?
Blade is the key component of fan, which involves structure, pneumatics, technology and other fields. The length of the blade is proportional to the power of the fan. The longer the power is, the longer the blade is. As the existing materials can not meet the needs of high-power wind power generation devices, the performance of glass fiber composites has reached the limit. Therefore, it is imperative to use carbon fiber composites with better performance in the development of larger power wind power generation devices and longer rotor blades. When the blades exceed a certain size, carbon fiber blades are cheaper than glass fiber blades, because the material consumption, labor force, transportation and installation costs are reduced.
Based on this, Yan Bing, Technical Director of Jiangsu Aosheng Composite Materials Co., Ltd., made a detailed comparison of several carbon fiber wind power applications, including large gram weight prepreg, carbon fiber fabrics, reinforced carbon panels and so on. At the same time, several examples of carbon fiber wind power applications at home and abroad were listed. Considering the whole life cycle of wind turbines, carbon fibers will have a wider application prospects, he said. However, we still need to correctly look at the problems existing in the application of carbon fiber materials. Future research will focus on large tow carbon fiber, technological innovation, thermoplastic carbon fiber composite blades, carbon fiber composite recycling and so on.
Carbon fiber wound cylinders are mainly used in aerospace high-pressure cylinders, respirator cylinders, automotive cylinders, transportation cylinders, etc. They have already been commercialized applications, such as hydrogen storage cylinders for 2008 Olympic Games, hydrogen storage cylinders for 2010 Shanghai World Expo and the only domestic passenger of Shanghai Rongwei 950 70MPa in 2016. Vehicle applications, etc.
Jiang will introduce the key technologies and application advantages of 70MPa type III hydrogen storage cylinder and 70MPa type IV hydrogen storage cylinder, and analyze the status quo of composite cylinder health monitoring technology at home and abroad. In the aspect of safety evaluation and monitoring of working condition, micro-nano sensor is used to monitor the state of composite pressure vessel in self-tightening, water pressure, impact, blasting test and working process, and the stress-strain state of COPV liner and carbon fiber composite layer is expected to be obtained. In the aspect of life-cycle health monitoring, micro-nano sensor is used to monitor the stress-strain state of composite pressure vessel. The stress-strain state of the composite pressure vessel in its life cycle is expected to realize the health state determination of the composite pressure vessel.
▲Yu Muhuo, Deputy Director of State Key Laboratory of Fiber Material Modification, Donghua University
China's manufacturing industry has a huge potential market, which is expected to lead the development of lightweight composite industry. Yu Muhuo, deputy director of the State Key Laboratory of Fiber Material Modification, Donghua University, believes that the application of lightweight composite materials in manufacturing industry and the development of its key technologies have the following main trends: first, the global capacity of carbon fibers and aramid fibers is constantly expanding and the cost is constantly decreasing; second, the manufacturing technology of carbon fibers and aramid fibers is constantly improving and the cost is not high. Third, the performance of carbon fibers and aramid fibers has been continuously improved; fourth, the rapid development of composite material automation production technology; fifth, various industries have begun to try to use composite materials. In China, wind power, large passenger aircraft, high-speed rail vehicles (hydrogen cylinders, battery boxes, transmission axles, hub, leaf springs), construction, ocean, chemical and other industries have been in progress. Sixthly, for target parts and components, research and development of low-cost technology system for the whole industry chain will give great opportunities to leading enterprises in the market segmentation.
The key technology of large-scale application of composite materials in manufacturing industry is low cost. Focusing on the realization of low cost, he introduced in detail the R&D direction and achievements of his R&D team, including the research of integrated structure of CFRP chassis battery box, industrialized production and application of thermoplastic composite preprepreg, design of CFRP battery box structure (low cost + automatic mass production + lightweight), electricity. Research and development of special prepreg for tank (room temperature storage + rapid curing + flame retardant) and CFRP high-speed railway bogie, etc.
What is the future development trend of carbon fibers?
Song Dewu, chairman of Jilin Chemical Fiber Group, introduced in detail how to control the production process of carbon fiber precursor from the aspects of polymerization and raw liquor, spinning, oxidation, carbonization and sizing. In particular, he stressed that in the production process, high purity, densification, fine crystallization, homogenization and other aspects should be guaranteed to ensure the performance of the fiber. The reason is that high-quality precursor is the primary condition for the preparation of high-performance carbon fibers. Minimizing impurity defects can improve strength. Homogenization of precursor, preoxidized fibers and carbon fibers can basically uniform the radial distribution of fibers'structure and properties, without obvious skin-core structure, shorten preoxidation time, improve efficiency and reduce the formation of carbon fibers. Ben.
For the future development trend of carbon fibers, he believes that enterprises in the industrial chain division of labor will be more meticulous, large tows will become more prominent, fine denier, differentiation is the direction, precursor production is more and more attention. Based on this, he put forward the following suggestions for the future development of carbon fibers: first, to support continuous production and large-scale carbon fibers manufacturers, only industrialization and scale can promote quality progress and cost reduction; second, market-oriented and differentiated, highlighting their respective characteristics need to differentiate, to achieve efficient application and reduction. Fifthly, carbon fibre and composite materials are a complex science, depending on industry foundation and market development, to find and do the right thing for people. Sixthly, the operation of carbon fibre industry needs to pay attention to safety and environment. Protect.
▲Duan Xiaoping, President of China Chemical Fiber Industry Association
At the main forum in the afternoon, Duan Xiaoping, Vice President of China Textile Industry Federation and President of China Chemical Fiber Industry Association, made the keynote report. He analyzed the importance, necessity and urgency of sustainable development from the definition and connotation of sustainable development, the background of resources and environment faced by the industry, and the technical system supporting sustainable development. He also discussed several aspects related to sustainable development-innovation, intelligent manufacturing, plastic particles and solutions, materials science. Technology and green development, talent and R&D and on-site guests exchanged.
In addition, the conference issued the "Three-year Plan of Action for Green Fiber Certification (2020-2022)", and also held the award ceremony of "China Chemical Fiber Industry Association Hengyi Foundation" Excellent Papers and "China Chemical Fiber Industry Association Sanhuading Excellent Fund" Excellent Engineers and Excellent Technical Workers.
In the academic exchange link, the winners/representatives of the award of "Excellent Academic Papers of China Chemical Fiber Industry Association Hengyi Foundation" in 2019--Zhou Youwan, a professor of Southwest Jiaotong University, Wang Dong, a professor of Wuhan Textile University, and Hao Minerong, a professor of Donghua University, and Li Xianhua, a senior engineer of Baling Petrochemical Co., Ltd. made a special topic. Presentation.
Source of article content reprinted: Sinochem New Network