Carbon fibre reinforced plastics

 

Key data

Level: RWTH

Partners: 3

Duration: 10.2013 - 03.2014

 

The production of primary carbon fibre is an energy-intensive process at approximately 700 MJ/kg C-fibres. Therefore, the recovery of end-of-life fibres from carbon fibre reinforced plastics (CFRP) and conversion into a new CFRP-product offers great energy-saving potential. Furthermore, the effects of the environmental footprint can be reduced significantly.

The overall project objective is to recycle and recover secondary fibres from complex CFRP-components, which can then be processed to CFRP-fleece components.

As a first step, even fibre lengths need to be achieved through adjusted comminution of CFRP-components at the Department of Processing and Recycling. This is important for subsequent pyrolysis. After suitable comminution the fibre material possesses optimal properties and the pyrolysis process can operate at an optimal level.

Following comminution, the CFRP-material is thermo-pyrolytically treated in the technical lab of the Unit of Technology of Fuels. The main goal is to separate its different components as much as possible. Besides determining optimal process parameters, generated products are analyzed and the energy-efficiency (LCA) of the process is evaluated.

  Photo of carbon fibre with 10cm scale Copyright: Department of Processing and Recycling

At the Institut für Textiltechnik (department of textile technology), recycled carbon fibers are assessed with regard to their suitability for a composite-manufacturing. A quasi-isotropic C-fleece is remanufactured from secondary C-fibers by means of an aerodynamic fleece-production process. In the following, secondary CFRP samples are produced from quasi-isotropic C-fleece material and analyzed with regard to their mechanical properties and compared to known values of primary CFRP samples.

Based on gathered characteristic values, the influence of the recycling process on the mechanical properties of C-fibers and CFRP test can be determined.

Acknowledgement

The project is being supported by the Exploratory Research Space @ RWTH Aachen within the frame of the federal and state excellence initiative.