"High-performance fiber low-cost manufacturing technology" theme salon held in Beijing

The development of high-performance fibers represented by carbon fiber is a manifestation of a country's comprehensive strength. In the top ten areas identified by “ Made in China 2025”, seven areas are closely related to high-performance fibers. Recently, the theme salon of “High-performance fiber low-cost manufacturing technology” sponsored by the Beijing Branch of the International Association of Advanced Materials and Manufacturing Engineering (SAMPE) was successfully held at Beijing University of Chemical Technology. The purpose of this activity is to share the experience and insights of low-cost manufacturing of high-performance fibers through the communication, production, learning, research and use of various units in the high-performance fiber industry chain, and promote technological upgrading and innovation in the industry.

This issue of the salon focused on the "low cost, stable preparation" and "industrial application" of carbon fiber. Professor Liu Jie, Director of the Carbon Fiber Engineering and Technology Research Office of Beijing University of Chemical Technology and Executive Director of SAMPE Beijing Branch, attended the event. Associate Professor Wang Xiaoxu from the School of Materials Science and Engineering, Beijing University of Chemical Technology, Chen Youzhen, Researcher of Ningbo Institute of Materials, Chinese Academy of Sciences, Zhongfu Shenying Carbon Fiber Co., Ltd. Yang Rui engineer, senior engineer of the lightweight technology department of BAIC New Technology Research Institute, Shang Hongbo, senior engineer, Wei Guojun, deputy general manager of Jinggong Technology Co., Ltd., shared the topic, carbon fiber manufacturing enterprises, research institutes and high-performance fiber application units Thirty representatives attended the salon discussion.

Associate Professor Wang Xiaoxu introduced the research progress of high performance and low cost carbon fiber preparation by National Carbon Fiber Engineering Technology Center of Beijing University of Chemical Technology: 1. From the perspective of constructing a new technology theory system, the spinning by radical polymerization initiated by irradiation is explained. The pre-oxidation process uses microwave rapid carbonization and plasma surface treatment to complete the high-speed carbon fiber rapid and low-cost preparation. 2. By irradiating the existing large tow carbon fiber precursor for 30 seconds, the exothermic peak is greatly advanced and smoothed, thereby shortening the preoxidation time. 3. The nano-scale carbon fiber precursor is obtained by the method of electrospinning, the probability of defects of the single fiber is reduced, and the strength of the carbon fiber is further improved. 4. Reduce the cost of carbon fiber processing and manufacturing through 3D printing manufacturing technology. 5. Improve the comprehensive strength, modulus and fatigue resistance of carbon fiber by nano-modified high-performance fiber composites .

From the perspective of molecular structure design, the researcher Chen Youzhen explained the difference in PAN thermal performance caused by the use of functional initiators to regulate the end group structure to improve the free radical polymerization reactivity ratio: 1. It can improve the degree of cyclization of PAN homopolymer and make the polymerization product The thermal stabilization performance tends to be uniform. 2, the use of the appropriate PAN molecular weight, to help balance the final carbon fiber performance and thermal stability behavior consistency. 3. PAN modified by end groups is expected to obtain a more uniform structure during rapid pre-oxidation.

Yang Rui, engineer of Zhongfu Shenying Carbon Fiber Co., Ltd. introduced the current carbon fiber production capacity and output of Zhongfu Shenying Company: now has 4 polymerization lines, 6 raw silk lines and 10 carbonization lines. The current production capacity of raw silk is 13,000 tons/year, and the carbon fiber production capacity is 6,000 tons/year. The annual production capacity of the existing production line is about 3,000 tons. It is pointed out that the current cost of PAN-based raw silk accounts for about 70% of the cost of carbon fiber, and the cost of manufacturing carbon fiber can be effectively controlled by reducing the manufacturing cost of raw silk. It also introduces the current cost reduction measures adopted by Shenying Company: 1. By reducing the manufacturing cost by producing large tow carbon fiber, Shenying has completed the 24K carbon fiber trial production this year. 2. The line speed of dry-jet wet spinning raw silk is increased to 400m/min, which is more than 4 times that of wet spinning (Dongli's dry-jet wet spinning line speed reaches 700m/min). 3. Using rapid pre-oxidation technology, the pre-oxidation time is shortened to 34 minutes.

Wei Guojun, deputy general manager of Jinggong Technology Co., Ltd. introduced the progress of low cost from the perspective of carbon fiber manufacturing equipment: 1. Improve the localization rate of equipment manufacturing and reduce the investment in fixed assets. 2. Improve the wire speed of the production line and extend the single production operation cycle. (Design production line has a single operation cycle of 45 days and wire speed of 12-15m/min.) 3. Improve the energy consumption of carbon fiber production by increasing the width of the roller and preheating recovery technology.

Shang Hongbo, senior engineer of Lightweight Technology Department of BAIC New Technology Research Institute introduced the technical development background of automobile lightweighting and the application status of carbon fiber reinforced composite materials in the automotive industry. It is pointed out that: 1. The high price restricts the development of carbon fiber in the automotive industry, and it is urgent to develop low-cost carbon fiber reinforced composite material production technology. 2. Carbon fiber composites need to develop rapid prototyping automation manufacturing technology to adapt to the production cycle of the automotive industry. 3. Need to solve the problem of maintenance and recycling of carbon fiber reinforced composite materials.

After the topic sharing, the participants had a heated discussion on the preparation of non-PAN-based raw silk, the application direction of pitch-based carbon fiber, and the manufacture of standardized products of carbon fiber reinforced composite materials. Professor Liu Jie pointed out in the activity summary that different products have Different performance requirements and positioning. Carbon fiber is used as a reinforcement material in composite materials. It is necessary to select suitable materials according to the industry characteristics and performance requirements of the products, and further reduce the manufacturing cost of the composite products through optimized design and automated processing. The development of modern science is largely due to the innovation of interdisciplinary research. The domestic carbon fiber industry has been in the status of tracking international advanced technology for the past 40 years. With the advancement and innovation of science and technology, it is hoped that the domestic carbon fiber industry will have the opportunity to catch up with the international advanced level. .

After the discussion, the participants visited the National Carbon Fiber Engineering Technology Research Center of Beijing University of Chemical Technology. Through the exchange and sharing of this salon, it is understood that the current domestic carbon fiber manufacturing technology still has a certain gap from the international advanced level in terms of quality stability, spinning speed and capacity production. With the gradual deepening of domestic understanding of carbon fiber basic research and application, domestic carbon fiber manufacturing enterprises, carbon fiber equipment manufacturing enterprises and research units have realized that it is necessary to improve the industrial application of carbon fiber through the low cost of carbon fiber, and to innovate in the theoretical system of carbon fiber preparation. There has been some progress in manufacturing. The low cost of carbon fiber is a relative concept. It needs to be positioned according to the product. Combined with structural design and low-cost manufacturing technology, the corresponding materials are applied to the suitable products to achieve the appropriate cost performance.