Low cost pitch-based carbon fiber debuts

The high price of pitch-based carbon fiber normally restricts its use to limited applications such as heat dissipation materials for electronic devices installed in satellites. Now, a Japanese company is targeting wider adoption of such fibers with a new material that costs around half as much to manufacture

Mitsubishi Plastics, Inc. (Tokyo) has debuted Dialead K13C6U: an ultra-high-modulus grade of pitch-based carbon fiber that reportedly excels in heat conductivity and rigidity. Production efficiency has been raised by tripling the number of filaments per fiber bundle to 6,000 (6K) from 2,000 (2K) via optimization of graphitization processes. The significant reduction in production costs is expected to expand sales of the product into a wider range of applications, including components for avionics devices, heat sinks, LEDs, and automobiles.

There are currently two main classifications of carbon fiber; polyacrylonitrile (PAN)-based and pitch-based. Pitch-based carbon fiber exhibits excellent tensile modulus (rigidity) and heat conductivity and on this account, it is possible to manufacture carbon-fiber-reinforced-plastics (CFRP) with near zero coefficient of thermal expansion. However, this high rigidity makes it difficult to handle pitch-based carbon fiber during secondary processing, and the higher price of the product compared to that of metallic materials and PAN-based carbon fiber presented challenges for the carbon fiber manufacturers to expand markets.

Dialead K13C2U is Mitsubishi Plastics' existing high-end product used in space applications that exhibits a tensile modulus of 900 GPa and excellent thermal conductivity of 620 W/mK; levels almost triple that of aluminum. As it is in the highest price category of pitch-based carbon fiber, cost reduction was deemed necessary in order to expand its scope of applications. Responding to this challenge, the Company developed Dialead K13C6U, which retains the same level of modulus and thermal conductivity but is half the cost.

Heat dissipation capacity is an important design factor to realize smaller, lighter and higher function parts and materials for electronics equipment, LED lighting and automobiles. The lightweight pitch-based Dialead K13C6U carbon fiber with excellent heat dissipation performance and rigidity is expected to be adopted as a heat dissipation material in a wider range of applications.