Views: 9 Author: Site Editor Publish Time: 2023-06-08 Origin: Site
Foaming can make materials lightweight and endow them with various powerful functions, such as insulation, buffering and energy absorption, sound absorption and noise reduction, adsorption and filtration, and low dielectric insulation. Not only that, plastic foam can also play a more important role in areas such as carbon reduction, environmental protection, new energy, recycling, and sustainable development.
Recently, the "2022 Plastic Innovative Material Application and Processing Technology Summit Forum" was grandly held in Shanghai. Professor He Yadong, Chief Engineer of Nanjing Chuangbo and Ph.D. supervisor of Beijing University of Chemical Technology, delivered a wonderful speech at the conference on the preparation technology of PET lightweight structural core materials and their applications in wind power and other fields.
“Green” PET Supercritical Fluid Reactive Extrusion Foaming Technology
Foaming is the most important way to achieve lightweight polymer materials. Foaming materials play an important role in fields such as national dual carbon strategy, new energy, aerospace, 5G, and packaging, shoe materials, and automobiles in people's daily lives.
He Yadong stated that currently, high-performance foam materials and their preparation technologies are monopolized by developed countries. Through the continuous efforts of domestic enterprises and the close integration of raw materials, processes, and equipment, China has successfully developed the integrated process technology of PET supercritical fluid reaction extrusion foaming, which has significant advantages and reaches the international leading level.
He introduced that the non-drying PET reactive extrusion foaming integrated molding unit is based on the process technology of twin screw to single screw double stage continuous extrusion foaming integration. Especially, the continuous extrusion foaming PET dry free technology does not require pre-crystallization drying of raw materials, which can significantly improve equipment production efficiency, reduce energy consumption and equipment investment.
In addition, the supercritical carbon dioxide composite foaming system can also achieve a completely non combustible foaming agent system, greatly improving process safety, significantly reducing cell size, improving cell uniformity, and ultimately improving the comprehensive mechanical properties of PET foaming materials. These two major technical features are not possessed by foreign technology.
The integrated technology of PET non drying reaction chain expansion supercritical fluid foaming is still a safe and green process technology. By using this technology, not only conventional bottle grade PET resin can be used as the foaming matrix resin, but also recycled PET bottle sheet material can be used as the main resin, and corner waste can be fully recycled and treated. Therefore, it has advantages such as energy conservation, efficiency, safety, environmental protection, and high cost-effectiveness, achieving stable and continuous extrusion production of high foaming rate PET boards and sheets.
PET Lightweight Structural Core Material Helps China's Wind Turbine Blades Take Off
With the implementation of China's dual carbon strategy, wind energy, as a green energy source, has rapidly developed. Blade is a key component in the wind power system, and China's wind power blade production capacity accounts for more than half of the world. In the application of wind turbine blades, structural core materials are the key materials for wind turbine blades, accounting for over 25% of the blade cost. The stable supply and self-sufficiency of lightweight structural core materials are crucial for the sustained, healthy and rapid development of China's new energy industry.
“PET is a thermoplastic material with the characteristics of recyclability and reusability, making it the most promising lightweight structural core material among blades. All PET core blades are an important development trend in wind power technology.”
For example, he said, "Last year Shanghai Electric launched the S89 blade, which was the longest onshore blade in the world, marking the official entry of a new era for landing wind turbines. Except for retaining 1 cubic meter of light wood in the blade, the high-strength core material is made of PET foam material.
Mr. He Yadong further shared that the TMT185 blade independently developed by Zhuzhou Times was taken offline in Ordos in March this year, with a blade length of 91 meters, which is currently the longest onshore wind turbine blade that has been taken offline in China. The structural core material in TMT185 blades has been batch switched from PVC cross-linked foam to PET foam material. The domestically produced PET lightweight structural core material has been used in bulk for the first time in onshore wind power blades over 90 meters, marking a comprehensive performance catch up of China domestically produced PET foam materials.
Shanghai Electric independently developed the 100 meter wind turbine blade S112, which passed the static load test according to the EC61400-23 standard. The test data is highly consistent with the conceptual design, verifying the high reliability of this ultra 100 meter carbon fiber blade design. The structural core material in S112 blades has also been switched from PVC cross-linked foam to PET foam material in bulk. Currently, YD100 products using critical fluid foam integration technology are being used.
He stated that China domestically produced PET foam core material has been used for the first time on blades above 100 meters and passed static load testing, marking a technological breakthrough in the design and application of lightweight structural core materials.