Sustainability in the manufacturing of composite materials: A literature review and directions for future research

Composite materials showed great potential in replacing metal components in several applications allowing adequate component strength with reduced weight. From a sustainability point of view, a significant number of studies demonstrated that a component made of composite materials is one of the best responses to the recent global legislation for the reduction of energy consumption and CO2 emissions. The sustainability of the production of composite components should be assessed by structured approaches that consider the whole life cycle of the component from the raw material production, the manufacturing process and post processes to the end-of-life (EoL). The purpose of this paper is to present the state-of-the-art life cycle inventory (LCI) data available in the literature for a composite product. Works evaluating the embodied energy of the most common fibres and polymeric matrixes are collected. Each manufacturing technique is reviewed regarding energy efficiency by considering the specific energy consumption (SEC). Among the potentialities which characterise the EoL of a composite product, a focus is given to the recycling techniques. Future research challenges are proposed and discussed. The outcomes revealed a considerable dispersion in embodied energies and SEC values for both the reviewed materials and technologies. The SEC is the only descriptor for process efficiency. However, there is a lack of investigation into the relationship between the process parameters, processed materials, component size and energy consumption. In particular, for additive manufacturing processes, no data were found. In addition, the literature on using natural fibres as a sustainable alternative and recycling methods and their impact is extremely limited.