The street-facing faade of a newly-built office building belonging to Bouygues Imobiliria in Lisbon, Portugal, is formed by laminated glass panels made with strong and stiff DuPont SentryGlas interlay…
The street-facing faade of a newly-built office building belonging to Bouygues Imobiliria in Lisbon, Portugal, is formed by laminated glass panels made with strong and stiff DuPont SentryGlas interlayer. The ability of SentryGlas to create highly-resilient laminates with excellent post-breakage performance has allowed the faade engineering specialist Facal, of Santo Tirso (Portugal), to create a comparatively thinner, lighter glazing that is able to cost-effectively meet building and safety requirements and requires comparatively small point fixtures to hold the panels securely in place. Facal, a company recognized nationally and internationally for its pursuit of technical innovation in faade engineering, developed and installed the laminated glass faade for the Explorer building at the Parque das Naes in Lisbon. Measuring 20 meters high and 10 meters wide, the faade consists of approximately 40 laminated glass panels produced by the glazing specialists Vicer of Maia, Portugal. According to initial calculations, a laminate construction using a standard polyvinyl butyral (PVB) interlayer would require the two glass sheets to be each 12mm thick in order to provide the required long-term resistance to the specified wind loads. Moreover, it would require a comparatively expensive supporting framework with very large fixtures would be required to withstand the weight of the panes and the additional wind forces. However, because SentryGlas interlayers are five times stronger and approximately 100 times stiffer than PVB, a thinner glass construction can be used to achieve the same load-bearing capacity of the PVB alternative. For Facal this meant that, by using a laminate construction consisting of 10mm strengthened glass + 1.52mm SentryGlas + 8mm tempered glass, they were able to reduce the thickness and the weight of the panels by 25%. This in turn meant that the point fixing system developed by Facal to hold the panels securely in place could be made smaller, and therefore less obtrusive, than those required for the equivalent glass laminated glass panels made with a PVB interlayer. These combined benefits also result in a more cost-effective glazing solution with regard to the faade“s production and installation. Te post-breakage behaviour of laminated safety glass made with SentryGlas was a further critical safety factor in the selection of the DuPont interlayer for the Portuguese faade, as a spokesperson at Facal explains: Our primary concern was that of providing increased safety and ongoing protection in case of glass breakage and fallout. This is of particular significance in Lisbon, a city susceptible to seismic movements. With some of the glass panels as high as 20 meters above street level, it is essential that the integrity of the glass faade is retained and there is no risk of fragments of glass falling on to passers-by. Thanks to its excellent post-breakage performance, and the fact that the glass fragments remain adhered to the interlayer, this is assured with SentryGlas. Further benefits of SentryGlas interlayer include its high, crystal-clear transparency, its virtually universal resistance to yellowing and excellent edge stability. DuPont Glass Laminating Solutions provides materials, services and innovations to makers and specifiers of laminated glass. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food; building and construction; communications; and transportation. The DuPont Oval, DuPont and SentryGlas are registered trademarks or trademarks of E. I. du Pont de Nemours and Company or its affiliates.