Japan’s Teijin Limited has developed the country’s first prepreg, or carbon fiber sheet, pre-impregnated with bismaleimide (BMI) matrix resin that offers high resistance to both heat and impact, thereby making it ideally suited to use in aerospace engine components.
|Teijin’s new BMI resin pre-impregnated prepreg achieves a high glass transition temperature (Tg) of 280°C and compression after impact (CAI) of 220 MPa.|
Teijin’s new BMI resin pre-impregnated prepreg achieves a high glass transition temperature (Tg) of 280°C and compression after impact (CAI) of 220 MPa, which is said to be a previously difficult combination realized by Teijin’s proprietary resin-composition formulating technology. The new prepreg also reportedly maintains its coefficient of linear thermal expansion and high dimensional stability at both low and high temperatures. Moreover, by adjusting resin viscosity, Teijin has also improved moldability by adjusting the resin flow through preforms in the mold cavity and reduced curing time with its new prepreg compared to conventional BMI-based prepregs.
Prepregs are generally impregnated with lightweight, high-intensity epoxy resin. Conventional BMI resin-impregnated prepreg is already used for high-temperature applications such as aerospace engine components to prevent degradation and deformation, however, it normally loses its impact resistance when heat resistance is increased. Also, CFRP made of BMI resin tends to peel apart and crack when subjected to strong impacts. In addition, molding BMI resin can be difficult due to its liquidity.
Teijin, having developed technologies to adapt its prepreg for engine components, is now working on other high-heat applications for aerospace. These efforts will be supported with the knowhow and global marketing channels of Renegade Materials Corporation, a provider of highly heat-resistant composites, which Teijin recently decided to acquire.
Teijin will exhibit the new prepreg in the Teijin booth (hall6, G28 & J28) at JEC World 2019, the world’s leading composites exhibition, which will take place from March 12 to 14 in Paris.
Teijin is rapidly expanding its market for next-generation aircraft components by developing midstream-to-downstream lineups and related applications, such as cost-effective carbon fibers with higher-tenacity and higher-tensile modulus and intermediate materials including thermoplastic prepreg. Going forward, Teijin intends to further strengthen its position as a leading solution provider for aircraft applications, targeting annual sales in this field in excess of $900 million by around 2030.
Prepregs, which are intermediate materials for carbon fiber reinforced plastics (CFRPs), are used in fields ranging from aircraft and automobiles to infrastructure and leisure. As such, their prescribed properties must differ widely depending on the application. To address specific needs, technologies for various combinations of carbon fiber and matrix resin and for specific processing needs continue to be developed.