Better, bolder, bigger
By Chris Davis, composites manager at HB Fuller Kommerling.
Glass technology is an incredibly exciting place to be now, with the growth of ‘smart facades’ and function glass.
Companies are taking existing safety, solar and thermal performances, incorporating the latest research and development in BIPV (building integrated photovoltaics), switchable technologies, coatings and embedment, and delivering architects and engineers with new and exciting ways to use glass, both on its own and combined with hitherto incompatible and/or new materials.
The new range of liquid, optically clear, adhesive (loca), products hold the key to developing and delivering what is being termed ‘function in glass’, which encapsulates active or dynamic components between the glass to improve wellbeing, with features for optical or thermal enhancement.
Intelligent buildings are becoming a reality and this is leading to increasingly more complex composite and IG specifications. The bedrock for many of these advancements in glazing technology is clever, ‘wet chemistry’ used in bonding insulated and laminated glasses together.
Some pioneering applications are now in the final stages of development, giving architects and designers the impetus to start thinking differently about how the much-flaunted concept of the intelligent building can become the reality by using these ground-breaking approaches. In the meantime, there are several areas where function in glass is becoming far more widely specified and an accepted part of modern day building design.
Safety glass. The use of wet chemistry to bond the glass to together generates a far superior chemical type adhesion, combining strength with a robust post failure performance. This delivers internal and external solutions that meet both aesthetic and legislative requirements for safety, structural, attack resistant and dynamic fenestration applications, eg, balustrades, glass partitions, staircases and other interior structural elements.
Security glass. Specialist loca products add real value in terms of optical quality and production yields. They will compensate for differential thermal movements of asymmetric materials such as glass and polycarbonate, while ultimately providing protection from ballistic and manual attack Successfully bonding polycarbonate into a multi-layered glass specification significantly reduces panel weights and the amount of spall (flakes of material, often glass shards, that are released from the non-impact side following projectile impact or blast). Multi-layer glass-to-glass or glass-to-polycarbonate specifications have already been developed and successfully installed in civil buildings, high security installations, prisons and specialist vehicles, where weight is also a consideration.
Sound reduction. To accomplish this, the resonant surfaces need to be decoupled. This is achieved with the application of soft compliant composites that improve glass-to-glass acoustic insulation and promote the dissipation of sound energy. The exponential growth in road, rail and air travel has fueled the demand for improved acoustic well-being through construction specifications in domestic dwellings, education establishments, healthcare facilities, offices and residential care homes.
Clients and architects are driving the interest and growth in this area, as they recognise that while the natural light is desirable, excessive sound penetrating their buildings is detrimental to delivering quality environments that promote rest, recovery, study, work or enhance general day-to-day living; all now recognised as a core requirement of the design brief.
Structural applications. Glass-to-glass specifications are widely used in the architectural market for glass flooring and on high, visual impact, interior design features. Loca materials exhibit shear, creep and relaxation behaviour that greatly enhances the mechanical performance and service life of the finished laminate, particularly in applications where time and temperature dependency may be more critical.
UV protection. Demand is increasing for the specialist colourless liquid composite, designed for applications where the highest reduction of ultra violet light transmission across the full UV light spectrum is required, without affecting the quality of naturally transmitted light. By using the actual fabric of the building, in the form of specially protected windows to provide UV protection, art galleries, historic houses, museums or even luxury, private residences receive an extra layer of UV protection that can be combined with an improved, inherent safety performance.
Not only do composites offer benefits to the building occupiers, there are also great additional benefits to be gained in the production process in terms of curing speed, improved production capacity, low post cure rejection rates, and the wide range of substrates that can be laminated with a passive curing process. Passive curing is a low energy solution for lamination that strengthens the green credentials of loca processors.
Architects (and, consequently glass and facade engineers) are constantly pushing the boundaries, and laminating glass panels to deliver enhanced performance criteria, and adding features to the interlayer itself help make these specifications possible.
The design flexibility, process and behaviour characteristics, along with the benefits of a passive curing profile, synonymous with wet lamination, are fuelling the growing focus on adding function to glass.
There will always be a role for foils but as our expectations of buildings, their performance and the materials from which they are constructed continue to expand, then the role of the liquid composite is one that is only going to increase.