Flexible plastic packaging is still one of the most difficult streams to recycle due to the presence of multilayers. With multilayers being very functional during their use phase, the delamination of  multilayer structures is promising because it enables the recovery of the constituent polymer layers without any degradation and/or dissolution, thus creating economic and environmental benefits. However, there is hardly any data available on the optimization of the delamination process for multilayer flexible plastic filmds (MFPFs), as well as the potential scale-up in terms of economic and environmental factors. Therefore, this study investigates the effect of experimental parameters such as temperature, solid/liquid (S/L) ratio, particle size, and stirring rate on the delamination rate of various MFPFs. Among these parameters, the combination of temperature and S/L ratio has the most pronounced effect on increasing the delamination rate. On the other hand, particle size does not have a significant influence on the delamination rate. Under optimal delamination conditions, more than 90% delamination is achieved in 60 min, particularly for PET-based MFPF. Simulations of the delamination process in Aspen Plus® reveal that the composition of MFPF has a significant effect on the energy consumption during the delamination process. The slower delamination kinetics of MFPFs can be compensated for through process optimization, but this typically results in higher energy requirements. The life cycle assessment (LCA) confirms that high energy consumption results in high CO2 emissions; thus, design for MFPFs, together with process optimization, are key aspects of obtaining a competitive delamination process with economic and environmental benefits.

The full article can be found at https://www.sciencedirect.com/science/article/pii/S0921344922001045.