Building a sustainable future with waste plastic

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Recycling our plastic containers and bottles has become second nature, but recycling capability restrictions mean we still throw away huge quantities of soft plastics such as bread bags, crisp packets and fruit and vegetable wrappers. Unable to be recycled using kerbside infrastructure, these plastics are put in our general waste bins and inevitably end up in landfill sites, where they often get blown off site and pollute our environment. A constructive, large-scale solution to the proliferation of soft plastics is needed.

Stronger together

Dr Dipa Roy, Reader in Composite Materials and Processing, leads thermoplastic composites research at the University of Edinburgh. Dr Roy has identified the potential for these waste soft plastics, which are very low value and mechanically low performing, to be made into value-added products when combined with another waste product: glass fibres. Together with Sean Smith, Professor of Future Construction and Director of the Centre for Future Infrastructure, Professor Dilum Fernando, Chair of Structural Engineering, and Professor Conchúr Ó Brádaigh, Chair of Materials Engineering, Dr Roy is utilising waste soft plastics and waste glass fibres to create composites that can be both rigid and flexible, a range of thicknesses, and that can be easily moulded into various shapes and sizes. The properties of these composites offer huge potential for their application across the construction industry, which the research team and their industrial partners are exploring in order to identify the most appropriate route to market.

The research team, which also includes PhD student Kit O’Rourke and Dr Danijela Stankovic Davidson, Post-Doctoral Researcher, has completed a feasibility study funded by the EPSRC Future Composites Manufacturing Research Hub, and a follow-on EPSRC IAA project to develop value-added composites from mixed waste plastics and waste glass fibres was also successful. Multinational glass fibre manufacturer Johns Manville and Irish polymer engineering company Paltech were already working with the team, but the IAA project allowed the researchers to develop a relationship with UK composite manufacturer Capvond, rounding out a complimentary rather than competing team of industrial partners who are able to provide technical advice and in-kind contributions. In recognition of the work they are doing to transform waste materials into innovative and versatile new products, the University team were recently selected from a global pool of nominees as finalists for the Institute of Materials, Minerals and Mining’s Sustainable Future Awards in the Circular Economy category.

Towards a sustainable future

The academic and industrial partners are committed to finding not only a viable solution to the problem of waste soft plastics, but to the construction sector’s considerable waste problem. The construction industry accounts for an incredible 36% of worldwide energy usage, and 40% of CO2 emissions, and there is growing pressure on construction firms to reduce their environmental impact. Replacing virgin materials with waste product composites will not only contribute to a reduction in land, water and air pollution, it will also bring companies in line with sustainable construction goals and the UK Government’s Construction 2025 strategy.

Technologies that can increase the potential of recycling and reuse of plastics are a crucial milestone in the journey towards net zero. Currently undergoing testing, the composites developed by Dr Roy and her team are poised to provide a green alternative to existing virgin products, which will prevent vast quantities of waste soft plastics and glass from going to landfill and help embed sustainable practices in the construction sector – as well as other industrial sectors - both home and abroad.