Circular IGUs–coating of reclaimed float glass

Abstract Advancing circular economy practices in the construction sector require the development of reuse and remanufacturing pathways for high-quality building materials such as architectural glass. This study investigates the technical feasibility of remanufacturing float glass reclaimed from insulating glass units (IGUs) through the application of functional coatings. Uncoated double IGUs were dismantled, and the reclaimed glass panes were reprocessed and coated with solar control layers using industrial-scale magnetron sputtering at a production site in Germany. The coated samples underwent various testing methods as part of the plant production control, assessing their optical, mechanical, and spectral properties in comparison with reference coatings applied to new float glass. The results demonstrate that reclaimed float glass can be successfully reintroduced into industrial coating lines, achieving comparable performance to conventional substrates. The paper presents experimental results and outlines the critical processing steps and conditions required for successful coating application. Furthermore, it discusses the technical challenges associated with remanufacturing at scale and provides a baseline for future studies aiming to define a set of criteria for successfully coating reclaimed glass substrates. The findings confirm the technical viability of this approach and highlight its potential to significantly reduce raw material demand, energy use, and embodied carbon in future closed-loop glass production systems.