The latest glass laminates
By Chris Davis, composites manager at Kommerling UK.
It is now accepted by architects that access to natural light is beneficial to the final users of the space – be that a young family, care home residents or office staff in the latest central London international HQ building.
Skylines across the globe reflect this quite literally with a dazzling array of expansive glass facades that shimmer in spring sunshine and allow the atriums and offices within to come alive.
While it is hard to fault this approach, using glass on such a vast scale does have some problems. These include increased UV light levels, an increased risk of damage to people and property in the case of an explosion, and the ever-present sound of the city penetrating the interiors. Overcoming these possible barriers to the use of glass is driving the development of liquid composites.
Architects and specifiers are now demanding glass that has a multi-layered capability. This means that the finished facade should not only meet the requisite mechanical properties, providing integral strength for the overall structure, but will also combine that with the need for sound insulation, heat efficiency and fire resistance for example.
The challenge of applying these laminates is that their application must not be detrimental to the clarity of the finished glass; if the interior light quality is impaired then any benefit from the laminate will be negated.
Liquid composite laminating materials meet many of these challenges, and are also proving their worth in the bonding of mixed substrates such as non-asymmetrical materials, materials with different stresses, uneven surfaces and non-glass. Adding additional layers to existing intumescing products requires a ‘passive curing’ laminating process with low temperatures and pressures that will not affect the clarity of the glass or add any additional weight to the finished unit.
One area of progress is in acoustic protection. Specialist buildings such as care homes, healthcare facilities and educational establishments recognise that excessive sounds penetrating their buildings could be detrimental to recovery or study. Their patients or staff need protection from the noise of the outside world. Current debate about Heathrow’s third terminal the associated threat of noise pollution, is a very real example of how the awareness of noise and its possible negative affects is reaching a wider audience.
Developments in sealant technology mean that insulated glass (IG) units can now be constructed using a compliant composite on one or both leaves designed to improve insulation performance. Differing glass thicknesses resonate at different frequencies, therefore a sensitive choice of substrate thicknesses in conventional IG design can avoid the harmonies that in effect amplify rather than reduce the passage of sound.
Additionally, incorporating glass substrates laminated together with specialist acoustic inter-layers helps decouple the resonant surfaces, thus promoting the dissipation of sound energy. It effectively helps absorb some of the energy transmissions related to noise attenuation.
Glasscraft is one company that has recognised the opportunity for supplying acoustic glass units and has made significant investments in its manufacturing capabilities to meet this growing demand.
Earlier this year it installed a new production line at its Wakefield site, capable of producing up to 1,200 units a day. Bob Norris, MD, said: “The last year has seen an increase in enquiries from people wanting to increase the acoustic resilience of their buildings, be it new build or refurbishment. Using Kommerling’s Kodiphone laminate we have developed a range of units that meet the highest standards in terms of structural capability, but have the added benefit of sound dampening without any detriment to the actual clarity of the glass.”
So, while glass will always be chosen primarily for its aesthetic value there is no doubt that with the advancement in laminating techniques the enhancements that it can bring to quality of life for residents will keep it at the top of the architect’s list for the foreseeable future.