Influence of edge finishing on the resistance to thermal stresses of float glass

Vincenzo M. Sglavo, DIMTI - University of Trento and Christine Müller & Francesca Righetti, Glas Müller Vetri Spa

Thermal stresses can arise in float glass architectural applications due to differential exposition to sun radiation or interior heating. The intensity of thermal stress depends on the temperature distribution within the sheet and is related to the difference between cold and warm areas, the former being usually localized in the fixing and fastening devices that shield the glass from sun or interior heating or dissipate heat more easily acting as thermal bridges. Several factors can influence the thermal stress like sun radiation intensity, colour, thickness and thermal properties of the glass, insulating properties of the glazing, presence of low-E coatings, thermal bridges, etc.. The possibility that the glass sheet subjected to thermal stresses fails depends practically only on the conditions of the edges and in particular on the presence of flaws. These are created upon cutting and processing (e.g. during handling, coating, fixing, gluing, etc.) the sheets and specific procedures are often used to reduce the defects on the edges by removing layers of material chemically or mechanically. In the present work the influence of different edge finishing on glass resistance is analyzed. Glass plates are subjected to identical industrial cutting procedure. The edges are then machined by different procedures to reduce the intensity of the defects. Successively, the samples are subjected to mechanical tests. The results are used to correlate by statistical methods the edge finishing procedures to possible thermal stresses, which arise in typical architectural applications.

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The Authors

Prof. Vincenzo M. Sglavo Prof. Univeristy of Trento - Dpt. Materials Engineering Professor of Glass Science and technology and Ceramic Science and technology (Faculty of Engineering, University of Trento, 1995 to date) Research topics: fatigue phenomena in glasses and ceramics, m... Read more