"Extensional rheological application technology" is an innovation of energy-saving and high-efficiency extrusion (mixing) system. This project is a key research and development topic of the Ministry of Science and Technology. Dalian Rubber & Plastics Machinery Co., Ltd. (hereinafter referred to as " Daxiangsu ") signed a strategic cooperation agreement with South China University of Technology, and used the company's test center to actively participate in undertaking some project tasks and tests.And obtained the exclusive right to use this technology in products such as "large extrusion granulation unit and internal mixer". After the project achieved phase results, Daxiangsu actively used Daqing Petrochemical's 70,000 tons/year PE continuous mixing and extrusion pelletizing unit for engineering test verification. In order to complete the replacement of the new screw as soon as possible and reduce the impact of the shutdown on the user's production, Daxiangsu dispatched an elite team to complete the screw replacement in only three days, and the unit started smoothly and operated stably.