TOKYO — Plant-derived cellulose nanofiber is the post-carbon fiber wonder material of the future, and Japanese manufacturers and organizations are working on putting it to practical use.
Known as CNF, the fiber is lighter and stronger than steel and easy to recycle, giving it great potential in various fields, especially in the automotive and housing industries. Automakers see it reducing vehicle weight and improving fuel efficiency, while construction companies hope to use it as insulation in housing.
On May 11, representatives of about 20 organizations, including auto component makers Denso and Toyota Boshoku as well as Kyoto University, gathered at Fuji Speedway near Mount Fuji in Shizuoka Prefecture, west of Tokyo, to participate in a workshop hosted by the Environment Ministry. The event was held to announce the results of CNF research as an automotive material.
Arimitsu Usuki, a research adviser at Toyota Central R&D Labs., a research arm of Toyota Motor group based in Aichi Prefecture in central Japan, said he wants to make a concept car using CNF and put it to practical use by fiscal 2019.
CNF is made by treating pulp chemically and mixing it with resin in a special machine. This breaks the fibers down into much finer specks measuring just a few nanometers in diameter, allowing them to easily penetrate the resin. A nanometer is one-billionth of a meter.
It weighs one-fifth that of steel, but is five times stronger. Usuki aims to use CNF to reduce the body weight of cars and thus carbon dioxide emissions as well.
Auto component makers are already conducting research on applications. Denso wove CNF into the resin of large containers for vehicle air conditioners. Aisin Seiki announced a plan to make air intake components for engines with CNF-based resin, while Toyota Boshoku said it will make the inside of doors with resin made from the fiber.
Yohei Kawada, deputy director of the Environment Ministry’s climate change projects office, said he is pinning hopes on CNF as the key to reducing vehicle weight as technologies for increasing the efficiency of automobile engines are approaching their limits. Japan, which leads the world in the number of CNF patents and theses, holds the high ground in technology and research.
CNF can also be used to make housing materials. Shizuoka University and others are conducting research into making materials with better insulation.
Using CNF to make insulation will contribute to maintaining sufficient strength even with widening gaps between building materials. Shizuoka University will calculate the gaps using computer simulations to verify the efficiency and strength of the insulation. The university plans to partner with construction companies to make the material on a trial basis.
CNF can also be used to make home appliances. Electronics maker Panasonic is conducting research for using the fiber to make refrigerators and washing machines. CNF has better insulation and is easier to recycle than glass fiber.
CNF is made from wood chips. It is still expensive to make, but manufacturing costs will be reduced to 300 yen to 1,000 yen ($2.68 to $8.93) per kilogram in the future. The focus will then be how to maintain stable supply. Nippon Paper Industries and other papermakers have started producing CNF, but usage will vary depending on CNF type. “It is unclear what type of CNF will survive,” Kawada said.