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What is said to be the world’s first use of carbon fiber reinforced thermoplastic (CFRTP) for structural parts in a high-volume production vehicle is being used in the optional CarbonPro pickup box for General Motors’s GMC Sierra Denali 1500 and GMC Sierra AT4 1500. Jointly developed by Tokyo-based Teijin LTD (U.S. office in Greenwood, S.C.) and Detroit-based GM at Teijin’s technical center in Auburn Hills, Mich., the Sereebo CFRT high-volume composites manufacturing process is specifically being used for the  pickup box’s inner headboard, side and floor panels. Compared to steel, CarbonPro is 40% lighter, offers 10 times greater impact resistance, is more corrosion-resistant, and is even more readily recyclable.

As reported previously by our sister publication Composites World (CW), Sereebo is designed specifically to meet the needs of the automotive industry to fabricate carbon fiber composite parts and structures at high volumes with short cycle times. The process combines a nylon 6 resin matrix with a mat of chopped carbon fibers (length ~20 mm), which are preheated and then molded/formed in a standard compression molding machine in cycle times of 60-80 seconds. Teijin has not revealed the form the nylon 6 takes, except that it is integrated in the carbon fiber mat. In addition, the carbon fiber is sized for the nylon 6 resin. The Sereebo process is capable of producing parts with relatively deep draws and large curvatures, with no wrinkling. In addition, changes in mat thickness allow for tailored fiber reinforcement to meet specific mechanical load requirements. Also, the way the fiber is oriented in the mat, isotropic properties can be moderately controlled.