Toho Tenax Co. Ltd, the core company of Teijin Group’s carbon fiber and composites business, has developed new technologies for efficient microwave carbonization and plasma surface treatment of carbon fiber reinforced plastics (CFRP).
Using the world’s first application of microwave energy carbonization under atmospheric pressure, Toho Tenax has achieved a tensile modulus of 240GPa or greater and rupture elongation of 1.5% or greater, both equivalent to levels found in industrial products.
The advanced carbonizing process was developed by examining the fiber- structure formation process when carbonizing a bundle of between 12,000 and 24,000 pieces of flame-resistant oxidized PAN fibers, and then developing an appropriate microwave processing method to carbonize this fibrous material.
Using direct heating with microwave energy, fibrous material is carbonized continuously without having to maintain a high-temperature oven, thereby saving time and energy, explained the company.
Toho Tenax has also succeeded in developing a carbon fiber ultra-fast plasma surface treatment technology using dry process. As said, the simplified process reduces energy consumption by 50% for the whole process, compared to the conventional carbon fiber production process. In addition, the ultra-fast treatment improves the adhesiveness of carbon fiber and matrix resin.
Toho Tenax’s research and development programs were implemented by Japan’s New Energy and Industrial Technology Development Organization (NEDO). NEDO began promoting the research and development of innovative materials and technologies in 2014.