Mitsubishi Rayon Co. Ltd., successfully developed a high performance intermediate modulus (IM) carbon fiber, Pyrofil MR70, which largely exceeds the performance of conventional IM carbon fibers.

Weight saving materials are in high demand for aircrafts, cars, and high-end products for sports and leisure. To save the weight, it is indispensable not only to improve the material strength but also to improve the material rigidity (modulus of elasticity), which allows making structures lighter and thinner. However, it was a very difficult issue to improve both the strength and modulus of carbon fiber at the same time, according to Mitsubishi Rayon Co.

New product MR70 is an innovative IM carbon fiber which has strength of about 7GPa (1000ksi) and modulus of about 325GPa (47msi) and exceeds MR60H, a conventional IM fiber of Mitsubishi Rayon, by approximately 20 percent on strength and by approximately 10 percent on modulus.

This high performance was achieved by having been able to realize the precise control of the carbon fiber microstructure and the exclusion of the defects by revisiting thoroughly from the manufacturing process of the precursor, which is the raw material fiber of the carbon fiber, through the all manufacturing processes of the carbon fiber.

Mitsubishi Rayon has already started production in a domestic plant and sent sample shipments to users for aerospace and sports-leisure applications.