BreakThrough Interview

Epoxy-Removed Recycled Carbon Fibers Will Drive Global Environmental Improvement & Contribute to Local IndustrySankentech Co.,Ltd


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President Kaneaki Ikenoshita of Sanken Tech Corporation


  • Contribute to worldwide environmental improvement by recycling resources
  • Explore the potential of recycled carbon fibers through advanced technology and bold vision
  • Joint R&D with Mizunami City Ceramic Industrial Technical Laboratory

Sanken Tech Corporation invents and manufactures construction materials. The company philosophy is “Aim for a recycling society & contribute to worldwide environmental improvement through recycled resources.” With advanced technology and bold vision, Sanken Tech is exploring the potential of recycled carbon fibers.

Recycled Carbon Fibers: The Result of Decades of Experience in the Construction Industry

President Kaneaki Ikenoshita is currently 79 years old. Decades of work in the construction industry gave him the experience and knowledge which led him to make recycled carbon fibers by recycling carbon fiber reinforced plastic (CFRP).
Ikenoshita began serious development of recycled carbon fibers after accepting a contract to build a plant. In a worst-case scenario, there was a risk that a fire in the plant would create enough heat that the insulation inside the fire doors would constrict and peel away, allowing the fire to spread. The client requested the development of a non-constricting material to prevent such a disaster.

Removing Epoxy to Reuse Carbon Fibers

Development of a non-constricting material reminded Ikenoshita of an earlier idea to produce construction materials using recycled carbon fibers by processing CFRP. His wider desire was to promote “global environmental improvement” and “contribute to local industry.”

Aichi prefecture is home to thriving automobile and airplane manufacturing factories. Each manufacturing process requires a number of different materials, but CFRP is especially important for airplane parts. Due to high costs require for recycling CFRP to extract carbon fibers, the CFRP recycling process is a nuisance to most companies. The majority of materials are dumped into land reclamation work instead.

Scraps of CFRP were taken from the production floor. Ikenoshita and engineers worked together on an innovative technique that successfully removed the epoxy and extracted reusable carbon fibers. Those extracted fibers were easily remolded into other items like carbon fiber tiles and sheeting.
The removed epoxy evaporates away during the manufacturing process, which reduces the amount of epoxy waste.

Epoxy is removed from treated CFRP scraps, and the fibers are processed into new items like carbon fiber insulation tiles and carbon fiber sheeting.

In addition, joint research with the Mizunami City Ceramic Industrial Technical Laboratory (Gifu prefecture) is using Mino-yaki techniques to make a prototype composite material that blends recycled carbon fibers into ceramic ware. This project created DANT carbon fiber insulation tiles, which have the following properties:
・Excellent heat resistance (non-constricting, protection up to 1200ーC)
・Light weight (floats on water, specific gravity 0.42)
・Easily processed (can be cut with a saw or blade, simple construction)
・Environmentally friendly (reuses production scrap material)

High Expectations: Certified by the Minister of Land, Infrastructure, Transport and Tourism

DANT carbon fiber insulation tiles were certified by the Minister of Land, Infrastructure, Transport and Tourism in January, 2018. In addition to providing non-constricting fire doors for plants that risk fire door material constriction and peeling, expectations are high for application in a variety of situations:
・Fire safety in restaurants through heat insulation and heat resistance to prevent fires caused by conduction overheating.
・Low energy operation and improved work environment through better heat resistance in industrial furnaces.

Target industries that resemble these examples include a diverse range of businesses from construction companies and construction material sales to manufacturers and the food industry.

Sound Equipment Innovation: Applying the Articulation Properties of Carbon Fiber

Even more recently, recycled carbon fiber is being used for audiophile accessories like room tuning panels. The audio and soundproofing design maker KOTOBUKI (Nagoya City) asked Sanken Tech for help improving the performance of its room tuning panels by using recycled carbon fiber. Using the articulation-boosting effect of carbon fiber, Kotobuki developed its Onkaisoku Gokuretsu (Rapid Sound Extreme) room tuning panels. Designed to articulate low frequencies under 80Hz, these cutting-edge room tuning panels focus the low range to reproduce a tight sound.

Onkaisoku Gokuretsu room tuning panels are made using recycled carbon fiber.
Sanken Tech made a huge leap through its first experience working on product development for regular consumer market items like Onkaisoku Gokuretsu.

Expanding Potential to Antique Houses & High Speed Expressways

Carbon fiber sheeting made with recycled fibers is also being applied in a project to restore antique houses. These sheets are applied inside the walls and floors to maintain comfortable temperatures without changing the appearance of traditional houses, which are notorious for poor insulation. Prevention of CO2 emissions means that this usage meets two goals at once.

Lately, a major glass manufacturer has also been talking with Sanken Tech about using carbon fibers for soundproofing along highways.
If this leads to a large order, then huge amounts of CFRP will be spared from disposal. Expectations are high for how recycling resources will contribute to global environmental improvement.

Recycled Carbon Fibers & New Plastic Composite Materials

Ikenoshita explains, “development work never really ends.”
Currently, he is working on a project to manufacture a new type of plastic composite material that blends carbon fibers with polypropylene (PP). Demo trials are already happening to test this plastic for industrial uses like construction materials, with possible expansion to consumer goods. Results are showing improved material strength. Development through industry-academia collaboration with Gifu University is also under consideration.
Sanken Tech believes that there are still better, bigger secret possibilities for both plastic composite materials and recycled carbon fibers. The future will surely bring more growth and innovations in carbon fiber technology.

Interview Date: December 19, 2018

company information

With its unique technology, our company extracts only carbon fiber from the scraps produced at the time of manufacturing CFRP used for aircraft parts and other materials, and turns them into ceramic composites. We apply the same technology to reuse graphite waste. We are making eco-friendly and recyclable products to create a recycling-oriented society.

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