Highly efficient production and characterization of CFRP made from recycled carbon fibers

Due to EU guideline 2000/53/EC in 2015 at least 95 wt% of newly produced cars will have to be recycled. Since carbon composites are growing in importance, efficient methods for further processing of recycled chopped carbon fiber materials have to be developed. A method of high interest, the wet-laying process, was investigated at the Institute for Carbon Composites. It is an efficient way to produce paper-like semi-finished products. To do this the dry fiber material and the composites made from this fabric were characterized with respect to the mechanical properties and processing behavior. Results of a comparison between wet-laids produced from virgin fibers and recycled fibers, each combined with cellulose fibers, were examined. Influencing parameters such as carbon fiber weight content in the paper, actual fiber type used or fiber length were identified and quantified based on the strength and stiffness of the dry material and the composite. On this basis the wet-laying process can be adapted to develop a recycled fiber material that can be used in automotive applications.