Advances in life cycle assessment of plastics with mineral fillers in packaging applications

Resumen

Mineral masterbatches, in other words mineral fillers, are concentrates of calcium carbonate or talc in a polymer base. In addition to their optimal cost, their use improves mechanical properties of materials and reduce energy consumption during the processing. Finally, their use may help to reduce the carbon footprint of the final product, since they include (at some percentages) naturally existing minerals (calcium carbonate and talc) instead of virgin petrochemicals. Due to the increasing environmental pollution that the world is recently facing, concerns over using plastic have also increased. Plastic packaging, origin of 30% of the total annual plastic production, is one of the major areas which requires special attention. Therefore, the main focus of this thesis is the environmental assessment of the use of masterbatches, with calcium carbonate and talc, in different plastic packaging applications by using life cycle assessment (LCA) methodology, as being the commonly accepted tool in estimating the potential environmental impacts of products or systems. While doing this, it is also aimed to provide advancements in the LCA methodology of plastic compound materials. In this thesis, through a collaboration with a producer of mineral masterbatches, different studies were performed based on real market cases. The outcomes of this thesis are: i) a deep and extended literature review on environmental impacts of functional fillers (including masterbatches) used in the industry; ii) two LCA case studies (“plastic compound vs eucalyptus wood storage sheets” and “virgin polyethylene (PE) vs eco-designed cosmetic tubes with mineral fillers and recycled content”), in which the use of plastics with mineral fillers is compared to virgin plastic alternatives; iii) introduction of methods, within the inventory phase, to calculate the quality loss (also known as Qs/Qp factors) of compound materials in open-loop and closed-loop recycling; and iv) introduction of a littering indicator, within the impact assessment phase, which estimates the probability of a supermarket bag contributing to the littering problem (in land and marine environments).