Packaging Glasses from Containers to Encapsulation: Composition, Performance, and Sustainability Pathways

This review synthesizes four decades of scientific and industrial developments in packaging glass, integrating structural, technological, and sustainability perspectives. Glass remains the benchmark material for inert, transparent, and fully recyclable containment, yet its scope has expanded from conventional bottles and vials to advanced functional and electronic encapsulation. Packaging glasses are classified into five main families—soda–lime, borosilicate, aluminosilicate, recycled (cullet-rich), and functional/electronic—and compared across key domains: mechanical, thermal, chemical, optical, barrier, and hermetic. Quantitative tables and normalized diagrams illustrate how compositional and processing trends govern structure, processability, and performance. Advances in forming, surface engineering, and melting practice are analyzed for their contributions to lightweighting, durability, and decarbonization. Sustainability is addressed through cullet utilization, energy demand, life-cycle indicators, and regulatory alignment, defining pathways toward circular and low-carbon production. Overall, packaging glass emerges as a circular, chemically stable, and traceable material system, while advances in high-integrity glass formulations now support hermetic encapsulation for diagnostic, electronic, and energy devices.