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How Is Carbon Fiber Made, and How Did It Begin with Bamboo?

Category: Technology

Fishing rods and bicycle frames often use black rods that are strong and light. When you hold them, they feel surprisingly light yet do not break easily. This material is called "carbon fiber." The history of this fiber actually involves a lightbulb and bamboo.

1. Why carbon fiber is lighter and stronger than iron

Carbon fiber is, as its name suggests, a thin thread made of connected particles of "carbon." These threads are bundled together and hardened for use [1]. A piece of carbon fiber the same size as a piece of iron weighs only about one-fourth as much. Despite being so light, its strength to withstand pulling forces is much greater than that of iron [1].

2. How Edison's lightbulb used bamboo from Kyoto

Around 1880, the inventor Thomas Edison was trying to create a lightbulb that would glow for a long time. He tested many materials, including wood, thread, and even hair, but it was not easy to find a good one [2]. The material he finally settled on was a filament made by charring bamboo (carbonizing it). Specifically, bamboo from Yawata in Kyoto, Japan, lasted the longest. This bamboo filament is said to have glowed for about 1,000 hours [2].

3. How a Japanese researcher created modern carbon fiber in 1959

The person who developed the basis for the carbon fiber used in around the world was also Japanese. In 1959, Shindo Akio, who was at a research institute in Osaka, discovered that charring a certain fiber produced strong carbon fiber [3]. After patenting this method, Shindo taught the technology to many companies. This sharing of knowledge is one reason why Japan still leads the world in carbon fiber production [3]. By spreading the technology across the industry rather than letting one company keep it secret, this approach was later named the "Shindo Model" by the Ministry of Economy, Trade and Industry. It is considered a good example of how public research institutions should operate.

4. How white acrylic threads are baked to turn black

Carbon fiber is not black from the start. First, white acrylic threads are prepared. These are slowly baked in air at temperatures of about 200°C to 300°C (392°F to 572°F) [4]. Next, they are baked in a place without air at much higher temperatures, exceeding 1,000°C (1,832°F). As this happens, everything in the thread except carbon escapes, resulting in a black fiber with carbon remaining [4].

5. Why Japanese companies still lead in carbon fiber production

Large Japanese companies still produce much of the world's carbon fiber. In particular, Toray is one of the world’s leading carbon fiber producers [5]. Toray’s carbon fiber is used in the Boeing 787 airplane, made by the American aircraft manufacturer Boeing. By making the body of the plane lighter, the passenger jet can use less fuel [5].

6. How carbon fiber is used, from fishing rods to rockets

Carbon fiber is used in many tools, taking advantage of its light and strong features. You can find it in fishing rods, bicycle frames, and golf clubs. It is also used in airplanes and artificial satellites that fly in space [6].

7. How to spot carbon fiber rods in things around your home

If you have a fishing rod, a bicycle, or a tennis or badminton racket at home, look for black, shiny rod-like parts. When you hold them, you might be surprised by how light they feel.

Sources

  1. Wikipedia "Carbon fiber", Kotobank "Carbon fiber" https://ja.wikipedia.org/wiki/%E7%82%AD%E7%B4%A0%E7%B9%8A%E7%B6%AD https://kotobank.jp/word/%E7%82%AD%E7%B4%A0%E7%B9%8A%E7%B6%AD-95241 (Carbon fiber is defined as a fiber with over 90% carbon by mass; it is about 1/4 the weight of iron but has much higher strength.)
  2. MLIT Multilingual Database, Yawata City "Edison Memorial Monument" https://www.mlit.go.jp/tagengo-db/R2-01481.html https://www.city.yawata.kyoto.jp/yawata-story/introduction/introduction008.html (Edison tested thousands of materials for lightbulbs and found bamboo from Yawata, Kyoto, worked best, glowing for about 1,000 hours.)
  3. Wikipedia "Akio Shindo", Postwar Innovation 100 Selection, AIST https://ja.wikipedia.org/wiki/%E9%80%B2%E8%97%A4%E6%98%AD%E7%94%B7 https://koueki.jiii.or.jp/innovation100/innovation_detail.php?eid=00053&test=open https://www.aist.go.jp/aist_j/news/announce/au20161101.html (Akio Shindo invented the method in 1959 and shared the technology with many companies, known as the "Shindo Model.")
  4. Carbon Fiber Association, Wikipedia "Carbon fiber" https://www.carbonfiber.gr.jp/material/manufacture/ https://ja.wikipedia.org/wiki/%E7%82%AD%E7%B4%A0%E7%B9%8A%E7%B6%AD (White acrylic threads are heated at 200-300°C in air, then over 1,000°C without air to remove non-carbon elements.)
  5. Toyo Keizai Online, ITmedia, AIST https://toyokeizai.net/articles/-/4391?page=4 https://www.itmedia.co.jp/makoto/articles/0902/16/news015.html https://www.aist.go.jp/aist_j/news/announce/au20161101.html (Toray holds a top global share; their fiber is used in the Boeing 787 to reduce weight and fuel consumption.)
  6. Wikipedia "Carbon fiber" https://ja.wikipedia.org/wiki/%E7%82%AD%E7%B4%A0%E7%B9%8A%E7%B6%AD (Carbon fiber is used in aircraft, satellites, cars, and sports equipment like fishing rods and rackets.)