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Known as the \"black gold,\" carbon fiber possesses properties such as high temperature resistance, friction resistance, heat conductivity, and corrosion resistance. It is widely used in industries such as industrial equipment and rail transportation, and it also represents a new generation of high-performance materials for manufacturing advanced equipment in defense, military, and aerospace fields. In the carbon fiber manufacturing process, although used in small quantities, the precursor fiber sizing agent and the carbon fiber sizing agent are essential key additives. However, these two types of high-end specialty chemicals have long been monopolized by a few foreign companies. Overcoming the technical challenges related to the production of high-strength and high-modulus carbon fiber precursor coatings as well as carbon fiber sizing agents, thereby enabling the use of domestically produced materials for carbon fibers, is of great significance for improving the level of autonomy and control over the entire carbon fiber industry chain in China. In the recently released list of “units selected for innovation tasks related to key products in the fine chemicals industry” by the Ministry of Industry and Information Technology, both the sizing agent for high-strength, high-modulus carbon fiber precursors and the sizing agent for carbon fiber composites—developed by Yulin Hengshen New Materials Co., Ltd. (hereinafter referred to as Yulin Hengshen)—made it onto the list. High-end general-purpose additives to be produced domestically. In terms of raw material sources and production processes, carbon fibers mainly include three types: polyacrylonitrile-based carbon fibers, viscose-based carbon fibers, and pitch-based carbon fibers. Among them, polyacrylonitrile-based carbon fibers dominate; they are made from acrylonitrile as the main raw material through polymerization, spinning, and carbonization. During the production process, the oiling agent for the precursor fibers serves primarily to form a uniform protective film on their surface; it provides lubrication and wear resistance, anti-static properties, bundling effects, high-temperature resistance and anti-adhesion characteristics, as well as protection for the fibers. It also directly influences the spinning stability and the ultimate strength of the carbon fibers. Similarly, carbon fiber sizing agents are specialized additives applied to the surface of finished carbon fibers, intended to improve the interface of composite materials, protect the carbon fibers, and facilitate subsequent composite manufacturing. “Although these two additives are not primary raw materials and their content in carbon fibers is minimal, they are both crucial for protecting the precursor fibers and ensuring product quality control. ”Yin Weitao, deputy general manager of Yulin Hengshen, said. In the field of coatings for high-strength, high-modulus carbon fiber filaments and sizing agents for composite materials, China lacks mature, high-end products of a general-purpose nature. Carbon fiber manufacturers face issues such as high costs, limited supply, and risks of supply disruptions; furthermore, frequent changes in these coatings lead to fluctuations in the performance of carbon fiber products and increased production costs. In this project, Yulin Hengshen, Jiangsu Hengshen Co., Ltd., and Shandong Nuoweya New Materials Co., Ltd. will work together to develop high-strength, high-modulus carbon fiber precursor coatings as well as sizing agents for carbon fiber composites that possess high process adaptability and versatile performance. These products are designed to meet the diverse and stringent molding requirements of various industries such as aerospace, new energy, and wind power, thereby filling the gap in this field in China. The three parties work together to overcome challenges. For this project, Yulin Hengshen serves as the leading entity, with Jiangsu Hengshen Co., Ltd. and Shandong Nuoweya New Materials Co., Ltd. acting as co-applicants. Jiangsu Hengshen Co., Ltd., which is part of the Shaanxi Coal and Chemical Industry Group, is one of the leading enterprises in China to have established a complete carbon fiber production chain. As a wholly-owned subsidiary of Jiangsu Hengshen, Yulin Hengshen is planning to build a high-performance carbon fiber production facility with an annual capacity of 20,000 tons in Yulin, Shaanxi. The first phase of this project, which involves a production line with an annual capacity of 5,000 tons, is set to enter the trial production stage by the end of 2025. Shandong Nuoya New Materials Co., Ltd. is mainly engaged in the research and development and production of carbon fiber additives. Three companies have joined forces to tackle these challenges by leveraging innovation platforms such as Jiangsu Hengshen’s Postdoctoral Research Station and Jiangsu Province’s Enterprise Technology Centers. Yin Weitao explained that the challenges associated with the oiling agents for high-strength, high-modulus carbon fiber filaments lie mainly in the storage stability of the emulsions, their high-temperature resistance, residual carbon content, and compatibility with manufacturing processes. The main challenges in carbon fiber composite sizing agents lie in high-temperature resistance, the development of high-performance bundling agents, and achieving a balance between bundling and unwinding. New products with optimized formulations are on the horizon. The oiling agent for high-strength, high-modulus carbon fiber filaments to be developed under this project will use modified silicone oil as the main polymer component, in order to address issues such as gelation, demulsification, and stratification that can occur when silicone oil is emulsified. Appropriate lubricants are developed for different process conditions such as wet spinning and dry spray-wet spinning, to ensure a stable oiling process for carbon fiber precursor filaments, preventing sticking to the rolls and any dispersion of oil. The carbon fiber prepared using this oil agent has high strength and low ash content; it is compatible with various resin systems, offers a wide range of application possibilities, and exhibits good processability. Regarding sizing agents for carbon fiber composites, the new products are compatible with resin systems such as epoxy, bismaleimide, vinyl, and thermoplastic types. They possess excellent versatility, wear resistance, bundling ability, and yarn spreading properties, meeting the application requirements in fields such as aerospace, wind power generation, and new energy vehicles. At the same time, this project will replace the existing main polymers and additives in sizing agents, establish a new testing system, and redesign the evaluation approach. Yin Weitao said that the three parties have jointly established a technical research team, and the research work is set to begin. The focus will be on researching and testing the formulas for oils and sizing agents, with completion of this research expected by the second half of 2028. By then, the project team will introduce 2 to 3 high-performance precursor oiling agents and sizing agents designed for various carbon fiber production processes, and will move from technical validation to industrial-scale production and mass sales, thereby contributing to the development of high-quality carbon fiber materials in China.