Advances in Structural Separation Technologies for Multilayer Packaging Recycling

ABSTRACT Multilayer materials have become an essential part of modern packaging design. They are engineered to merge different materials into a single, lightweight structure. However, their recycling is challenging because the layers are strongly bonded and chemically heterogeneous. As a result, multilayer packages (MLPs) often bypass recycling streams, causing environmental pollution and resource depletion. A potential long‐term solution is represented by disassembly processes that separate layers and direct them into single‐polymer streams. This review examines studies on separation technologies and categorizes them by their dominant mechanism of action. Delamination techniques chemically remove or deactivate bonding layers, whereas selective dissolution‐precipitation (SDP) uses polymer‐solvent thermodynamic windows to dissolve and recover polymer layers sequentially. For solvent selection, we consolidated Hansen Solubility Parameters to produce polymer solvent compatibility and distance maps for common polymers. Additionally, a detailed comparison is made of recovery outcomes, technology readiness levels, and their impacts on recyclate purity and food‐contact safety. Structural separation offers a feasible approach to reintroducing post‐consumer MLPs into mechanical recycling, provided solvent management, contamination control, and regulatory compliance are properly managed. We recommend prioritized research into closed‐loop solvent management, energy reduction, and scale‐up validation of promising delamination and SDP methods.