Most structural aerospace parts are manufactured using carbon fibre textiles pre-impregnated with a thermoset or curing polymer matrix. These “prepregs” are typically cured in large-scale autoclaves, a process that represents a daunting cost and environmental impact. Cutting of prepreg plies prior to layup generates large quantities of uncured prepreg offcuts which are nearly pristine when compared to other forms of composite waste. Offcuts are routinely sent to the landfill or pyrolyzed ignoring the value of the uncured resin, producing a recycled fibre with reduced strength and bonding properties, and requiring the introduction of a new resin and sizing for re-manufacturing.

In this work, we have developed a novel recycling framework for transforming aerospace offcuts into a strand-based compression moulding compound with mechanical properties similar to commercially-available SMC and BMC materials. This is achieved by altering the offcut's flow-compaction and curing behaviours through targeted modification of the resin's state of polymerization. 

Primary Publications

• A novel recycling framework for transforming uncured aerospace prepreg offcuts into a strand-based compression moulding compound with adjustable flow-compaction and curing behaviours 

Adam W. Smith, Pascal Hubert, Composites Part A, 2023 (Under Review)

• Uncured prepreg recycling methodology 

Adam Smith, Pascal Hubert, US20220305696A1, US Patent, 2022 

• Development of a Recycled Compression Moulding Compound

Adam W. Smith, McGill University, 2021

Primary Publications

• Geometric characterization and sieving of unidirectional carbon-fibre/PEEK prepreg trim waste

A.W. Smith, A. Legait, L. Plouzeau, J.P. Canart, I. Tabiai, M. Dubé, CANCOM12, 2022, Frederiction, Canada

Manufacturing of thermoplastic composites generates large volumes of high-value waste each year. This waste comes in many forms and with many different resin and fibre types. In this work, we aim to find different recycling methods that can be used create recycled compounds for injection moulding, compression moulding and stamp-forming. We hope to demontrate the feasibility of waste stream mixing so as to create a more stable recycling loop. 

Description coming soon.