Combination of Carbon Fiber Sheet Molding Compound and Pre-Impregnated, Tailored Carbon Fiber Reinforcements

The current use of fuel efficient and environmentally friendly aircraft is only possible by the development of innovative lightweight constructions and the use of lightweight materials, such as carbon fiber reinforced plastics. With the rising demand on fiber reinforced components in the aerospace industry new production processes have been built up. However, current production technologies for composites cause higher costs and obtain longer process cycle times in comparison to the manufacturing processes of metals. Moreover raw materials, such as carbon fibers and resin, and semi-finished products are very expensive. In contrast to this and compared with other manufacturing technologies for fiber reinforced plastics Sheet Molding Compound compression processes are characterized by cost efficiency, high productivity, the option of full automation and the possibility for the realization of complex shapes and integrated functions. However there are also some disadvantages like a low level of stiffness and strength in comparison to continuous fiber reinforced plastics. The reasons for these facts are the short fibre length, a lower fibre-volume fraction and an isotropic fibre distribution. Consequently, the combination of sheet moulding compound and pre-impregnated, tailored carbon fibre reinforcements in an one-shot compression moulding and curing process merges the advantages of both groups of composite materials. Therefore the creation of load-bearing, complex, functional and autoclave-quality parts without an autoclave can be realised. In this chapter, this innovative technology and its potentials are presented. This paper will also deal with the resulting material characteristics.

Keywords: Aircraft, CFRP, Hybrid, Light weight, SMC.