Glass has always been the only truly practical material to use for windows, as well as architectural additions such as conservatories, earning an iconic place in history and architecture. When toughened glass was first introduced, however, it brought not only a lot of immediate safety advantages but also a host of potential new applications, which more recent technological advances have only served to increase.
In sharp contrast to the large shards formed when breaking an annealed glass panel, toughened glass shatters into small granular fragments, which fall to the ground without causing much harm. This has meant that glass can now safely be used for purposes such as shower screens, sliding bi-fold doors and large expanses of exterior glazing, as well as balustrades and interior partitions.
Toughened glass was rapidly adopted in building design, especially as architects began to favour larger expanses of glass for its aesthetic qualities. However, it was the introduction of toughened laminated glass, a further advance in safety, which allowed us to push the boundaries of design in the building envelope.
In the process of lamination, two layers of glass are sandwiched together using an interlayer, which bonds the layers of glass together. This technique is normally used to combine two sheets of toughened glass, adding strength, safety, and a wide range of functionality. Very quickly, architects saw the potential for introducing greater use of natural light and more open spaces in the indoor environment.
Lamination has brought both increased strength and the ability to increase the size of the glass panel. Glass panels of several metres in height and width, can now be used in constructing both interior and exterior walls. These panels can also be joined unobtrusively, so that large expanses of glass can be made to appear uninterrupted, allowing architects to both imagine and realise increasingly innovative building designs.
Introducing more natural light brings additional benefits , including helping to reduce electricity consumption; and glass needs no redecoration, helping to lower long-term maintenance costs.
By laminating two layers of toughened glass, not only is safety enhanced, security can also be introduced. If a toughened laminated glass panel becomes damaged, it may become bowed or misshapen, but it will usually stay in place until it can be replaced.
Added security is a property that we can now purposefully introduce into glazed panels. By laminating thicker, specially processed security glass panes with advanced interlayers, we can create panels with built-in resistance to intruders, which will deter both vandals and would be thieves. Laminated security glass can now pass the standards for EN356 manual attack resistant glass, making it ideal for use in shop fronts, as well as inside retail outlets, in fixtures such as jewellery counters, or the screens used to protect bank employees.
Thanks to advances in glass processing, we can now help to design crime out of public buildings, deterring the use of firearms and ram-raiding by criminals, by installing ballistic and blast-resistant glass. Processing techniques now allow us to produce toughened laminated glass which passes the tests for ISO 16933:2007, which governs the standards for blast-resistant glass. This helps to make public buildings, in particular, more resistant to terrorist attacks, without having to compromise on design qualities. This type of blast-resistant glass is now increasingly specified for use in airports and rail stations.
To add still further protection, we can also add an LCD switchable interlayer to combine the properties of security and privacy in a single glass product. By using multiple interlayers, we can produce glass that is not only secure, but also opaque on demand. When a small electrical current is passed through the privacy interlayer, it becomes optically clear, allowing those inside and outside the property to see through it. By turning off the current, however, we make the glass completely opaque, obscuring the view of any prospective intruder’s target.
Thanks to the advances in interlayer technology, we can now produce tailor-made glass to suit almost any project. We are not restricted to adding one or other characteristic; using interlayer technology, we can now combine a whole range of functions in a single product. All this technology also comes with expert advice, so it is always worth discovering whether the specification of the right glass product can answer a whole range of construction challenges.