Circular materials for sustainable carbon fibre composites

Important results from the project

The project aims to find a way to reuse the epoxy pre-impregnated carbon fibres (CF prepreg) cut-offs. Today, 20 to 30 % of all prepreg material is discarded as arbitrarily shaped cut-offs and cannot, due to its shape, easily be reused for composite manufacturing. The proposed recycling method involves transforming the arbitrarily shaped cut-offs into uniform rectangles, dispersing them over a mould, and finally consolidating and curing them into a composite plate using vacuum and heat. Such plates are expected to have good mechanical properties and numerous potential applications.

Expected long term effects

The goal of the project is achieved as a number of composite plates are manufactured using the proposed method. The manufactured plates appear to be of good quality, without any visible dry spots and are expected to have good mechanical properties. This result supports the proposed recycling process and, as a consequence, can lead to a reduction in the amount of CF prepreg waste. A potential use of the recycled composite plates as the skin in a sandwich structure is investigated and two sandwich plates is manufactured for this purpose.

Approach and implementation

Different kinds of CF prepreg material from SAAB and Aston Harald are cut into uniform rectangles using a handheld cutting machine from Aplicator Systems. Various parameters, which influence the cutting performance are identified and adjusted. Using the proposed recycling method, new composite plates are manufactured. Thereafter, sandwich plates are manufactured with the mould side of the composite plates facing outwards for aesthetic purposes.