Quantifying environmental benefits of monomaterial transition in flexible packaging applications

The increasing use of plastic packaging has raised environmental concerns for their disposal. A barrier to recyclability is the popularity of multilayer solutions, consisting of different polymer films, with high-performance barrier, but with almost no material separability. Since circular economy calls for the design for recycling, a strategy is the reduction of structural complexity, favouring single-material configurations that can be processed in mechanical recycling streams. In this context, this work aims at quantifying the environmental benefits potentially associated to the substitution of multi-material food packaging with recyclable ones. Three types of products have been selected as case studies: coffee (1 kg), dried fruit (200 g), cheese (200 g). Through Life Cycle Assessments (LCA), their conventional packaging configuration composed of polyethene terephthalate (PET), polyethylene (PE), aluminium, in complex multilayers, were compared with alternatives based primarily on polypropylene (PP) or polyethylene derivatives. Primary data on packaging composition, production process, transports, auxiliary materials were collected, supplemented by secondary data from Ecoinvent database. Attention was paid to end of lives, modelled using national consortium reports and RecyClass European tool. Results shows that material choice and production influence packaging environmental impacts, with monomaterials generally performing better in gas emissions and eutrophication, while in resource- and water-related impacts show no clear advantage. End-of-life management is crucial, as proper recycling of monomaterials can significantly enhance sustainability, highlighting the need for consumer awareness and careful evaluation of trade-offs by manufactures. Since results depend on context and material, requiring case-by-case evaluation, future research need to expand products coverage.