Nano-structure control enhances CFRP potential

Carbon fiber-reinforced grades of thermoplastics such as polypropylene (PP) are nothing new but Japan's Toray Industries, Inc. (Tokyo) reports that it has succeeded in making performance advances that make such CFRP composites a more attractive option in automotive applications.
Specifically, Toray has applied nano-structural control technology to tailor the surface structure of long carbon fibers in order to improve dispersion and adhesion with the resin matrix. The surface structure differs depending on the resin matrix material. One consequence is that lower fiber loadings are necessary. Toray says that a CFRP grade of PP reinforced with 20 wt% of carbon fiber has a specific gravity of one and is more than 20% lighter than the equivalent glass fiber-reinforced PP grade with the same strength. When compared with conventional CFRP PP grades, Toray also reports a 30% improvement  flexural strength.
PP and PPS grades are under development at Toray, with some PP grades already commercially available. PPS grades exhibit a deflection temperature under load of 260°C in addition to inherent chemical resistance and flame retardance.
Target applications for PP grades include semi-structural components in automobiles and appliances. PPS grades, meanwhile, will target application in automotive components. Aerospace applications are also viewed as an outlet for both resin types. Toray also offers Nylon 6 and ABS, as well as Nano-Alloy grades of CFRP that combine two resins as the matrix material. Its latest offerings will be on show at the nano tech International Nanotechnology Exhibition & Conference 2012 at Tokyo Big Sight this February 15-17.-mpweditorial@ubm.com