The architectural trend towards transparent structures has resulted in a notable increase in the utilisation of glass in construction. In order to address the inherent brittleness of glass, laminated safety glass (LSG) is employed to meet the requisite safety standards regarding breakage, post-breakage, and residual strength. LSG is composed of at least two glass panes laminated into a monolithic composite with a polymer interlayer. This interlayer binds any glass fragments in the event of breakage and provides residual strength to the glazing. The bond between the glass panes and interlayer is crucial regarding the safety of the laminated glass.
An increasing number of cases are reporting delamination effects between interlayers and glass panes. The most common damage patterns observed include discolouration, the formation of bubbles between panes or within the interlayer, and the formation of air channels, either described as snowflake-like constellations or similar channels originating from the edge, a process often referred to as viscous fingering.
In the production process, clamps are often employed to apply pressure to the edges of the laminate in order to ensure optimal edge bonding. However, this can result in the generation of stresses within the LSG, particularly within the interlayer.
In an initial study, researchers have analysed the influence of different clamp types, load levels and temperatures on the edge of LSG specimen, monitoring the thickness before, during and after the exposure. These insights represent an important step towards understanding the internal stresses caused by forces applied on the LSG element during the lamination process.
The future objective is to ascertain whether these stresses, when subjected to environmental influences, may potentially contribute to delamination in installed glass elements. The findings of this research project are anticipated to provide insights into optimising lamination processes for enhanced durability and safety in architectural applications.