On the morning of August 9th, the technology achievement appraisal meeting of the "5000 ton DMSO dry spray wet spinning high-performance PAN based raw silk complete set of equipment and process" project jointly developed by Jinggong Technology and the industry university research team was successfully held in Shaoxing, Zhejiang.

The appraisal committee is composed of two academicians and five authoritative experts in the industry: Feng Zhihai, an academician of the CAE Member and a researcher of the China Academy of Launch Vehicle Technology, serves as the chairman, Zhu Meifang, an academician of the CAS Member and director of the National Key Laboratory of Advanced Fiber Materials, Professor Xu Lianghua of the Beijing University of Chemical Technology, Professor Ao Yuhui of the Modern Textile Technology Innovation Center, Professor Sheng Yunqing of Zhejiang Mechanical and Electrical Design and Research Institute Co., Ltd., Professor Chen Guojin of Hangzhou University of Electronic Science and Technology, and Hu Hongbo, a professor level senior engineer of Zhejiang Fangzheng Light Textile Machinery Testing Center Co., Ltd., all serve as expert members. The meeting was chaired by the Zhejiang Machinery Industry Federation, with Vice President and Secretary General Zhao Qun and Minister of Technology Development Zhu Lvyuan attending online. Sun Guojun, Chairman of Jinggong Technology, Li Aijun, President, and the core project team attended the meeting.

PAN based precursor is the core of carbon fiber performance formation, and its quality directly determines the stability of subsequent pre oxidation and carbonization processes, as well as profoundly affecting the mechanical properties of carbon fiber products. From the essence of the industry, the competition for high-performance carbon fibers is essentially a competition for the stable preparation ability of high-end PAN based precursor fibers. For a long time, the complete set of equipment and processes for the preparation of raw silk has been a key bottleneck for China's carbon fiber industry chain to break through, which further restricts the independent supply and industrial security in the high-end field.

Aiming at the pain points of this industry, Jinggong Technology, together with Zhejiang Huachuang Carbon Fiber Technology Co., Ltd. (the operating unit of the Provincial Manufacturing Innovation Center), Donghua University, and Zhejiang University of Technology, has spent two years focusing on breakthroughs and successfully developed a complete set of equipment and process technology system for 5000 ton DMSO dry spray wet spinning high-performance PAN based raw silk, promoting the independent and controllable core technology of the entire process of high-end PAN based raw silk preparation.

At the meeting, the appraisal committee listened carefully to the project report, carefully reviewed the complete set of technical documents including the project technical summary, novelty search report, inspection and testing report, production condition report, user application report, etc., and conducted on-site defense and in-depth questioning. After thorough discussion and evaluation, the appraisal committee unanimously agrees that:The research and development of the project product is successful, and the overall technology of the equipment is at the international advanced level. Among them, the DMSO recovery steam consumption and the temperature uniformity inside the polymerization kettle have reached the international leading level, and we agree to pass the appraisal.

The project integrates multiple hardcore innovations:

1、 Developed a 60m ³ large capacity high uniformity polymerization reactor and a complete set of precise temperature control technology.By adopting a special mixing and scraper collaborative strengthening structure, the axial circulation, near wall renewal, and bottom sweeping capabilities of the high viscosity system are enhanced. A jacket hot water coil cold water collaborative heat exchange system and multi-point temperature feedback control method are constructed, which solves the engineering amplification problems such as heat transfer lag and insufficient local mixing in the high viscosity polymer system, and achieves effective loading conditionsThe temperature uniformity inside the kettle reaches ± 0.4 ℃.

2、 Developed multi-stage symmetrical pressure distribution technology for main pipe branch pipe spinning positionUnder the conditions of 60 ℃ and approximately 1.6 MPa, the pressure deviation at the end of the high viscosity PAN solution reaches ± 1%, and the pressure fluctuation at the outlet of the spinneret reaches 1 ‰; Construct a stable control system for low-temperature coagulation bath, with a temperature of 5 ℃± 0.2 ℃ and a liquid level of 3 mm ± 0.1 mm. Develop a multi-channel curved steam stretching device to achieve a high-temperature steam stretching ratio of over 3.5 times; The process speed reaches 280 m/min,Raw silk production capacity reaches 5000 tons/year.

3、 Developed DMSO solvent separation, classification processing, and refined reuse technologyAchieve a DMSO recovery rate of no less than 99.5%DMSO recovery steam consumption not exceeding 2.2 t/tThe purity of DMSO recovered reached 99.88%, and the residual solvent content in the recovered wastewater was less than 100ppm.

4、 Constructed MOM intelligent production management system and central control visualization platformThe large-scale production process of raw silk has been visualized, with traceable quality, manageable equipment, and controllable energy consumption.

Since its establishment in the carbon fiber industry in 2013, Jinggong Technology has always adhered to the guidance of national strategic needs, focused on independent innovation of key core technologies, and continuously broken through the core links of the industry chain. The "5000 ton DMSO dry spray wet spinning high-performance PAN based precursor equipment and process" has passed the scientific and technological achievement appraisal, which is not only another important milestone for the company to adhere to scientific and technological innovation and climb the technological peak in the field of carbon fiber, but also marks a significant breakthrough in the key equipment and core processes for the large-scale preparation of high-performance PAN based precursor in China, and a leapfrog improvement in the domestic independent guarantee capability of key links.

In the future, Jinggong Technology will continue to anchor in the core field of carbon fiber, continuously iterate full chain equipment and process technology, empower strategic industries such as aerospace and new energy to improve and upgrade, and demonstrate greater precision in the process of independent, controllable, and high-quality development of China's carbon fiber industry.