I. Overview of High-Performance Fibers

High-performance fibers refer to chemical fibers with special physical and chemical structures, properties, and uses, or possessing special functions. Generally, they have extremely high tensile strength and Young’s modulus, and at the same time, they also have other characteristics such as high temperature resistance, radiation resistance, flame resistance, high pressure resistance, acid resistance, alkali resistance, and resistance to oxidant corrosion. They are widely used in fields like aerospace, national defense and military industries, transportation, industrial engineering, geotechnical construction, and even biomedical and electronic industries.

The early definition of high-performance fibers was based on mechanical properties, often referring to fibers with a breaking strength exceeding 15 cN/dtex, such as carbon fibers, para-aramid fibers, and ultra-high molecular weight polyethylene fibers. However, this definition has certain limitations in actual production and application. In a broad sense, fibers with properties like high temperature resistance, radiation resistance, and corrosion resistance are also called high-performance fibers, such as meta-aramid fibers, polytetrafluoroethylene fibers, and polyphenylene sulfide fibers. The main features of these products lie in aspects like heat resistance and flame retardancy.

High-performance fibers can be classified according to the attributes of materials. It includes metal fibers, inorganic fibers, and organic fibers. Metal fibers have relatively small scales in the family of high-performance fibers due to their high density and low specific strength. The main characteristics of inorganic fibers are high-temperature resistance, corrosion resistance, and excellent mechanical properties. They are widely used in fields such as aerospace and weaponry, including carbon fibers, silicon carbide fibers, boron nitride fibers, silicon-boron-nitrogen fibers, alumina fibers, basalt fibers, and glass fibers. There are many varieties of organic high-performance fibers. According to the characteristics of macromolecular chains, they can be divided into flexible-chain fibers and rigid-chain fibers. The typical representatives of flexible-chain organic fibers are ultra-high molecular weight polyethylene fibers and high-strength polyvinyl alcohol fibers. Their macromolecular main chains are composed of —CH2—, and the high orientation of molecular chains significantly improves the mechanical properties of the fibers. Rigid-chain fibers include aromatic polyamide fibers (i.e., aramid fibers), polyarylate fibers, polyimide fibers, poly(p-phenylene benzoxazole) fibers (PBO), and polybenzimidazole fibers. Among them, the latter three fibers are also called aromatic heterocyclic fibers. In addition, organic high-performance fibers can also be classified according to their typical characteristics, such as high-strength and high-modulus fibers (such as para-aramid fibers, high-strength polyimide fibers, PBO fibers, ultra-high molecular weight polyethylene fibers, etc.), high-temperature-resistant fibers (meta-aramid fibers, polybenzimidazole fibers, polyetherimide fibers, etc.).

High-performance fibers have special properties that ordinary fibers do not possess and are mainly applied in various fields of the military and high-tech industries. Most high-performance specialty fibers are made by wet spinning. Some fiber preparation processes are rather difficult. For example, first, fibers with linear or low molecular weights are spun using traditional spinning techniques, and then processes such as cyclization, cross-linking, metal chelation, high-temperature heat treatment, surface physical and chemical treatment, or plasma treatment are carried out respectively to obtain the finished fibers. There are also those that need to adopt new spinning processes such as emulsion spinning, reaction spinning, liquid crystal spinning, dry-jet wet spinning, phase separation spinning, high-voltage electrospinning, high-speed airflow melt injection, and special composite spinning techniques. Some also utilize existing synthetic fibers to obtain various ion exchange groups through functional group reactions or transform them into fibers.

High-performance fibers can be classified by performance into corrosion-resistant fibers, high-temperature-resistant fibers, flame-resistant fibers, high-strength and high-modulus fibers, functional fibers, and elastomeric fibers. ①Corrosion-resistant fibers: namely fluorine-containing fibers, including polytetrafluoroethylene fibers (Teflon TFE), tetrafluoroethylene-hexafluoropropylene copolymer fibers (Teflon FEP), polyvinylidene chloride fibers (Kynar), ethylene-chlorotrifluoroethylene copolymer fibers (Halar), etc. ②High-temperature-resistant fibers: including poly(m-phenylene isophthalamide) fibers (Nomex), polyimide fibers (Αримид ∏Μ), polyphenylsulfonamide fibers (СульФон – Τ), polyamide-imide fibers (Kermel), polybenzimidazole fibers (PBI), etc. ③Flame-resistant fibers: including phenolic fibers (Kynol), aromatic polyamide fibers with surface chemical treatment, metal chelated fibers, polyacrylonitrile pre-oxidized fibers (Pyromex), etc. ④High-strength and high-modulus fibers: including poly(p-phenylene terephthalamide) fibers (Kevlar), aromatic polyamide copolymer fibers (HM – 50), heterocyclic polyamide fibers (Βниивлон СΒΜ), carbon fibers (Carbonfiber : Torayca), graphite fibers (M40), silicon carbide fibers, etc. ⑤Functional fibers: including hollow fiber semi-permeable membranes (B – 9, B – 10, PRISM, etc.), activated carbon fibers (KF, etc.), ultra-fine fiber felts (Ф∏∏15, etc.), oil-absorbing fiber felts (Tafnel, etc.), optical fibers (Crofon, Eska, etc.), conductive fibers (Antron Ⅲ), etc. ⑥Elastomeric fibers: including polyester and polyether polyurethane fibers (Spandex), polyacrylate fibers (Anidex), polybutylene terephthalate fibers (Fibre – L), etc.

II. Current Domestic Development Status of China’s High-Performance Fiber Industry

1. Carbon Fibers
   China has a history of over 60 years in the research and development of polyacrylonitrile-based carbon fibers. Currently, China is still in the stage of expanding the application of the first-generation advanced composites with T300 and T700 as the main reinforcing materials, and the engineering application of T800-level carbon fibers is still in the research and development stage. Domestic carbon fiber precursor filaments have formed three production process systems, namely dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), and sodium thiocyanate (NaSCN). Although continuous breakthroughs have been made in core technologies, there is still a gap compared with Toray of Japan. There are many carbon fiber production enterprises in China, such as Zhongfu Shenying, Weihai Guangwei Group, Hengshen Co., Ltd., Jilin Jinggong, Shanghai Petrochemical, and AVIC Zhongjian Technology Co., Ltd. However, there are differences in product performance and production stability compared with international leading enterprises, and high-precision metering pumps, corrosion-resistant spinnerets, and ultra-high-temperature graphitization furnaces still rely on imports.
2. Aramid Fibers
   (1) Para-aramid Fibers
   China’s annual consumption of para-aramid fibers is around 1.1kt, and about 80% of the products still need to be imported. With the rapid development of transportation, optical fiber communication and other fields, the demand for para-aramid fibers will be even stronger. It is estimated that the domestic demand for para-aramid fibers will reach 30kt in 2025. The main early para-aramid fiber production enterprises in China include Chengrand Research Institute of Chemical Industry, SINOARA, Suzhou Zhaoda, Yantai Tayho and Yizheng Chemical Fiber. In recent years, Sinochem International has started to invest in para-aramid fiber production. With the technical support of Donghua University, it has relocated the para-aramid fiber production line of Suzhou Zhaoda to Yangzhou and jointly established Sinochem High-Performance Fiber Materials Co., Ltd. Yantai Tayho New Materials Co., Ltd. has also been continuously expanding its para-aramid fiber production lines, while acquiring Minshida and raising funds to build an industrialization project for high-performance aramid paper-based materials with an annual output of 3kt.

(2) Meta-aramid Fibers
The industrial concentration of China’s meta-aramid fibers has increased. Currently, the main production enterprises are Yantai Tayho New Materials Co., Ltd. and Supermax New Materials Co., Ltd. The downstream market of meta-aramid fibers is generally sluggish, and the prices of raw materials have risen, resulting in greater business pressure for enterprises. In this market environment, some companies have shut down their meta-aramid fiber production lines. At present, domestic meta-aramid fiber manufacturers have cooperated with the military to produce combat uniforms, providing a huge market space for meta-aramid fibers. Driven by market demand, Tayho New Materials has announced the addition of a 4kt/a meta-aramid fiber production line, which was put into production in August 2021, and the company’s meta-aramid fiber production capacity has reached the ten-thousand-ton level.

(3) Aramid III
The production line of China’s Aramid III was first built by Chengrand Research Institute of Chemical Industry. At present, the performance of domestic Aramid III ranks first among domestic mass-produced organic fibers, reaching the level of mass-produced products in Russia, and has been mass-produced stably and used in the military field. Besides Chengrand Research Institute of Chemical Industry, Guangdong Caiyan Co., Ltd., Sichuan Huiteng Technology Co., Ltd., and the 46th Institute of the Sixth Academy of China Aerospace Science and Industry Corporation have also successively carried out research and development work on heterocyclic aramid fibers.

3. UHMWPE Fibers
   With the development of applications, the demand for UHMWPE fibers in China has been steadily increasing, and the fiber production capacity has been gradually expanding. Currently, there are more than 20 UHMWPE fiber production enterprises in China, and the number of enterprises with a production capacity of over 1,000 tons is gradually increasing. The international market competitiveness of domestic UHMWPE fibers and products has been continuously enhanced, and the foreign trade export volume has gradually increased from 50% to over 70%.
4. PPS Fibers
   The main polyphenylene sulfide resin production enterprises in China include Zhejiang NHU Co., Ltd., Chongqing Jushi, Inner Mongolia Panxun, and Zhuhai Changxian. At present, the scale of China’s PPS resin industry is gradually expanding, but there are still problems such as a relatively low production technology level and a small number of product categories. In terms of the fiber industry, the production capacity of high-end fiber-grade chips is insufficient, and the market application fields are narrow.
5. PBO Fibers
   China started relatively late in the research on PBO fibers. After two or three decades of development, domestic universities and research institutes have made certain progress in the synthesis and spinning of PBO polymers. In terms of the industrialization of PBO fibers, China has also made important progress in recent years, and several PBO fiber production enterprises have been put into production one after another.
6. Silicon Carbide Fibers
   To break the blockade of developed countries, the National University of Defense Technology took the lead in carrying out research on the preparation of continuous SiC fibers in China and independently developed and established the first domestic production test line for continuous SiC fibers, obtaining products and technologies with independent intellectual property rights in aspects such as precursor synthesis, spinning, non-melting, and sintering. The performance of the prepared KD-type first-generation and second-generation continuous SiC fibers is in the leading position in China and at an advanced international level, and they have been used by multiple research units and application departments in China’s aerospace and other fields. They have successively won the first prize of the Military Science and Technology Progress Award (in 2014), the first prize of the Hunan Provincial Technological Invention Award (in 2014), and the second prize of the National Science and Technology Progress Award (in 2015). For the research and development of the third-generation SiC fibers, through hydrodecarbonization pre-sintering, the near-stoichiometric KD-S-type third-generation continuous SiC fibers were prepared, and their performance is equivalent to that of Japan’s Hi-Nicalon S fibers using the same hydrodecarbonization process. In 2016, the high-temperature sintering densification technology of SiC fibers was conquered, and for the first time in China, high-crystalline near-stoichiometric continuous SiC fibers, namely KD-SA-type third-generation SiC fibers, were successfully prepared. The composition, structure, high-temperature resistance, and creep resistance of these fibers are equivalent to those of the third-generation SiC fibers Tyranno SA abroad. At present, these fibers have been produced in small batches and provided for application departments, filling the domestic gap and making China the third country in the world capable of preparing high-crystalline near-stoichiometric continuous SiC fibers. Xiamen University has been engaged in the research on the preparation of continuous SiC fibers since 2002. It obtained the second-generation continuous SiC fibers with low oxygen content by electron beam irradiation cross-linking method and prepared the third-generation continuous SiC fibers similar to Japan’s Hi-Nicalon S fibers by electron beam irradiation followed by hydrodecarbonization method. The composition, structure, and performance of the fibers are equivalent to those of the corresponding second-generation and third-generation continuous SiC fibers in Japan. Since 2015, the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, has carried out research on the development of the third-generation SiC fibers similar to Japan’s Hi-Nicalon S fibers for the application needs of the nuclear industry. In addition, the Institute of Process Engineering, Chinese Academy of Sciences, has carried out research on zirconium-containing composite SiC fibers, and Central South University has carried out research on beryllium-containing SiC fibers. In terms of industrialization, in 2005, Suzhou Saifei Group Co., Ltd. docked with the National University of Defense Technology for the transformation of scientific and technological achievements and realized the industrialization of continuous SiC fibers in China for the first time in 2010. In 2016, Ningbo Zhongxing New Materials Co., Ltd. signed a cooperation agreement with the National University of Defense Technology to carry out the industrialization of the second-generation continuous SiC fibers. At present, a production line with an annual production capacity of 40t for polycarbosilane precursors and a production line with an annual production capacity of 10t for the second-generation continuous SiC fibers (Shincolon-Ⅱ) have been built. In 2019, the company signed a cooperation agreement with the Institute of Process Engineering, Chinese Academy of Sciences, to transform the second-generation continuous composite SiC fibers (Sericafila Z) and the third-generation continuous composite SiC fibers (Sericafila ZB). Fujian Liya New Materials Co., Ltd. has built production lines for the industrialization of the second-generation and third-generation SiC fibers with an annual production capacity of 10t since its establishment in 2015 in cooperation with Xiamen University. In 2018, the Silicon Carbide Fiber Division of Hunan Boxiang New Materials Co., Ltd. (now Hunan Zerui New Materials Co., Ltd.) built a production line with an annual production capacity of 10t for beryllium-containing silicon carbide fibers through the transformation of scientific and technological achievements of Central South University.
7. Basalt Fibers
   In 2002, the Ministry of Science and Technology included “basalt continuous fibers and their composites” in the “863 Program”, strengthening the development and promotion of the gas-electric hybrid melting and all-electric furnace production technologies with independent intellectual property rights, which enabled the rapid development of basalt fibers in China. However, currently, China’s basalt fibers generally follow a low-end route, mainly focusing on short-cut basalt fibers as reinforcing materials for concrete. In 2006, the first basalt fiber production line in China was developed by Shanghai Ejin Basalt Fiber Co., Ltd. Currently, there are more than ten enterprises engaged in the production of basalt fibers in China, with a total production capacity of over 100kt. Many enterprises have ten-thousand-ton production lines, including Jilin Tongxin, Henan Dengfeng Power Plant Group, Sichuan Fiberglass Group, Sichuan Qianyi, and Guizhou Shixin. However, the actual output of most enterprises is only several hundred to several thousand tons. The actual total output of China’s basalt fibers is 20 – 30kt, with specifications mostly between 10 – 20μm, and the price per ton is between 12,000 – 20,000 yuan. They are mainly used in cement concrete, asphalt concrete, vehicle transportation, high-temperature filter bags, and thermal insulation felts. At present, domestic basalt fiber production enterprises are still in the stage of low-price homogeneous competition, and further exploration is needed on how to improve the performance of basalt fibers. The drawing technology for large tows with 1200 holes or more is still unstable, and technical problems need to be overcome from multiple aspects such as raw materials, melting, and fiber-forming processes. Only by solving the drawing technology for large tows can the quality stability of basalt fibers be improved, the characteristics of high strength and high modulus of basalt fibers be truly exerted, the application range be broadened, and the bottleneck in the development of basalt fibers be broken through.

III. Current Problems of China’s High-Performance Fibers

1. There is still a generation gap in high-end fibers
   There is still a gap between China and developed countries in high-end fibers, and the ability to independently guarantee supply urgently needs to be strengthened. For example, the production technologies of high-strength and high-modulus, ultra-high-modulus carbon fibers, differentiated para-aramid fibers (ultra-high-strength type, ultra-high-modulus type, medium-modulus type, high-bonding type, anti-fatigue type, etc.), high-strength and non-creep UHMWPE fibers, and high-performance heterocyclic Aramid III have not been broken through, and the ability to independently guarantee supply is not available. In the field of high-performance inorganic fibers, there are also problems such as a lack of high-end products and poor quality consistency. Taking carbon fibers as an example, foreign aerospace fields have already applied second-generation advanced composites with T800-level carbon fibers as the main reinforcing materials on a large scale, while China is generally still in the stage of expanding the application of the first-generation advanced composites and verifying the second-generation advanced composites.
2. Industrial technology maturity is not enough China’s high-performance fiber industry has not yet fully mastered large-scale complete sets of production technology. At the present stage of domestic carbon fiber production is still 12K and the following small tow products, large tow, low-cost carbon fiber industrial production technology has not yet made a comprehensive breakthrough, while foreign countries have begun to large-tow low-cost and small-tow high-quality production technology fusion, and continue to improve product quality and reduce production costs. Aramid (para-aramid, meso-aramid, heterocyclic aramid Ⅲ) in the product performance and stability, production efficiency, industrial scale, application areas, etc. There are still gaps. UHMWPE fiber single line capacity is low, high investment costs, low production efficiency, high energy consumption, large-scale low-cost production is still difficult to achieve. PPS fibers and polyaramid fibers lack of kiloton industrialization of complete sets of technology and equipment. At the same time, the industrialization of complete sets of equipment design and manufacturing capacity is insufficient, the lack of design / simulation engineers, design / simulation software relies on imports, basic industrial technology (such as machining), precision equipment (such as metering pumps, spinnerets), the quality of raw materials for the equipment (such as high-strength steel, corrosion-resistant steel materials, etc.) and foreign countries there is a significant gap, resulting in the lack of independent equipment in the accuracy, efficiency and service life, the domestic. Poor operational stability of equipment, high failure rate, restricting the stability of China’s high-performance fiber product performance and enhancement as well as production cost control.
3. Insufficient investment in basic research China’s high-performance fibers to product development, focusing on solving the country’s major needs and applications of urgent needs. Universities and research institutes are usually based on model products, and the deep relationship between composition – structure – technology – performance of high-performance fiber materials has not yet been fully grasped, and the necessary basic scientific mechanisms and theories have not yet been revealed, resulting in a lack of theoretical support for new applications, and a lack of independent innovation capability. For example, China’s carbon fiber industrialized products are only a few grades, while Toray Japan has nearly 20 product models.
4. a sound industrial system has not yet formed China’s high-performance fiber industry system is not complete, the key equipment and supporting materials, important raw materials, product standards and testing and evaluation of weak links. In the aerospace, defense and military applications in the field of the overall scale is relatively small, it is difficult to drive the development and improvement of the whole industrial chain of high-performance fibers and composites, in the automotive, pressure vessels, rail transportation and other industrial areas represented by the large-scale application has not yet been achieved. Under the stimulation of multiple factors such as national policy support and investment impulse in high-tech field, there still exists low-level repetition and investment chaos detached from industrial reality, and the level of the project is uneven, which not only causes a large amount of national and social resources to be occupied and wasted, but also is not conducive to the competitiveness of the industry and the formation of a sustainable industrial ecology.

IV, the future development of China’s high-performance fibers

1. Strengthen the top-level design The current international environment is changing rapidly, should be led by the relevant state ministries and industry associations to plan the development of China’s high-performance fiber industry new path. This will help to protect the industry’s sound development, to prevent homogeneous production capacity from growing too fast, to avoid repeating the same old path of conventional fiber development, thus affecting the industry’s sustainable development in the future. At the same time, should support scientific and technological research and development and demonstration applications, adhere to the long-term investment, encourage iterative and stable development, promote the development of innovative products and large-scale application, high-performance fiber materials to drive industrial upgrading by technological progress.
2. Strengthen R&D innovation China should increase independent innovation efforts to build an enterprise-oriented, market-oriented, industry-university-research combination of technological innovation system. Focus on collaborative innovation, increase efforts to solve common problems restricting the high-quality development of the industry, focusing on short-board problems, strengthen the research and development of high-quality raw materials and auxiliary materials, key equipment and components, and enhance the independent and controllable capability of the industrial chain supply chain. Comprehensively grasp the deep relationship between high-performance fiber composition – structure – process – performance law, and enhance the ability of independent innovation. For example, referring to the case in “Yantai through the eyes of the media | Taihe New Material: taking the road of independent innovation to make China’s high-performance fibers on the world stage”, Taihe New Material adheres to the science and technology to develop enterprises, and has fully mastered the industrialization technology of the three high-performance products of meta-aramid, para-aramid, and aramid paper, and has become the only high-tech enterprise in China to realize the full series of aramid general products, It has become the only high-tech enterprise in China that realizes the full series and large-scale production of aramid general products.
3. Expanding production scale and developing low-cost process technology China in the focus on product performance and research and development of high value-added products at the same time, we should pay attention to the development of a variety of molding process technology, to further reduce costs and strengthen the ability to revenue. Production cost determines the market capacity and application, accelerate the development of low-cost technology is conducive to expanding the scope of application. Expanding the scale of production and improve the production capacity of a single line can further improve production efficiency and reduce production costs, thereby enhancing the market competitiveness of products. As mentioned in “China’s high-performance fibers and their composites development strategy research” released by the Chinese Academy of Engineering, high-performance fibers and their composites are the front-runner to lead the change of new materials technology and industry, widely used in many important fields, and they should adhere to the development idea of “product autonomy, technological autonomy, and system autonomy” to clearly define the development goals It should adhere to the development idea of “product autonomy, technology autonomy and system autonomy”, define the development objectives and key tasks, and promote industrial development in three aspects, namely, enhancing the design and application capability of composite materials, solving the problem of industrialized complete sets of equipment and building joint innovation platform.
4. Aiming at the market demand, increase the application technology development Drive the “upstream” through the “downstream” to form a series of products with independent intellectual property rights. Strengthen the communication and cooperation with supporting industries, from the design end of the finished product is actively integrated into the R & D work of downstream customers, efficiently maximize the excellent performance of high-performance fibers in the application scenarios, and truly realize the performance and downstream applications of the precise match. For example, Wu Jifa, a deputy to the National People’s Congress, suggested promoting the high-quality development of domestic high-performance fiber materials, further promoting upstream and downstream cooperation, guiding relevant enterprises to establish strategic partnerships, increasing the proportion of domestic high-performance fiber applications year by year to promote the application of domestic high-performance fibers in the high-end field of large-scale applications, the use of finance, insurance and other means to guide the formation of a support for the use of domestic high-performance fiber materials, the application of the market system.
5. Establish monitoring system to grasp the industry dynamics Sound high-performance fiber industry statistics, focus on industry data research, strengthen industry management and guidance. Planning and development, develop and improve industry access conditions, release product guidance catalog, to avoid blind development and low-level duplication of construction. Encourage the promotion of synergistic linkage and in-depth communication among manufacturers to guide the benign development of the high-performance fiber industry. For example, Shandong Tai’an’s high-performance fibers and composite materials industry chain special class by playing “take the lead” combination of punches, carry out “accurate service enterprise enterprise to help promote the development of the results” activities, custom “industry mapping and action plan”, build “I do practical things for enterprises” service development cloud platform, the establishment of the ‘collection + processing + closing’ problem disposal process and other measures, give full play to the industrial chain service guarantee, platform carrier and development leading role in promoting high-quality development of industries.
6. Strengthen the construction of standards to promote participation in international competition Focus on the construction of national standards and industry standards for high-performance fibers, including carbon fibers, aramid fibers, polyimide fibers, polyarylate fibers, polyphenylene sulfide fibers, UHMWPE fibers, etc., and their various types of downstream products of the method standard as well as the product standard, in order to regulate the domestic products of high-performance fibers, and to promote the products to enter the international market and participate in international competition.