| A common flexible packaging laminate is comprised of five constructs in sequence: printing layer, adhesive, barrier layer, adhesive, and sealing layer. Aluminum foil and metallized polymer films are commonly used gas barrier layers in flexible packaging, but their true environmental impacts are not well-represented. This study investigated the potential environmental impacts of three widely-used, five layer laminates, namely polyethylene terephthalate/aluminum foil/linear low density polyethylene, polyethylene terephthalate/metallized polypropylene/linear low density polyethylene, and polyethylene terephthalate/metallized polyethylene terephthalate/linear low density polyethylene in which the barrier layers are aluminum foil, metallized oriented polypropylene, and metallized polyethylene terephthalate. This study, with the use of SimaPro 8, was conducted to assess the total environmental impact, global warming potential, and embodied energy of these packaging alternatives across the life cycle. Compared to the aluminum foil laminate, the metallized polymer laminates offer reduced environmental impacts, though not as substantial as often cited. The results show that the MOPP laminate offers a 43% lower total impact and the MPET laminate offers a 40% lower total impact. Global warming potential is reduced by around 50% for both metallized polymer laminates, and a non-renewable embodied energy is 25-26% lower compared to the aluminum foil laminate. |
