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THE FRAGMENTED nature of the window manufacturing sector in the UK can mean that innovation takes time to filter through the market , but I think that bonded window technology , widely used in continental Europe , is set for a major expansion in the UK . This potentially has a huge impact on the volume manufacturers , but the smaller fabricator and installer businesses can capitalise on the advantages of the process quickly with readily available solutions .

With this method of manufacture , the insulated glazing panel is securely bonded into the sash with ultra-strong adhesive – a change that immediately improves the performance of the window . The majority of post-installation problems arise due to the failure or inaccurate placing of glazing blocks and these problems are removed immediately .

For the fabricator , application of the bonding adhesive is done using an applicator gun : it ’ s a quick and simple process and the adhesive can be used with most frame materials , so it ’ s a relatively easy switch to make , with training readily available from manufacturers such as ourselves .

For the volume window manufacturers , there is more investment required as switching to a bonded process will involve a change to the entire manufacturing process . However , the advantages , in terms of improved efficiency with a fully automated process and

a reduction in waste , will show a return in the long term .

More important , perhaps is the impact of the technology on the aesthetic design of windows . In the UK , as in much of Europe , PVC dominates the window sector . Marketed as a low-maintenance alternative to wood , the material grew rapidly in popularity when introduced some forty years ago and now accounts for around 60 % of the windows installed into homes .

However , it has some disadvantages in terms of both performance and appearance . Its lack of inherent strength means that the PVC frames generally need reinforcement – often achieved through the use of metal reinforcement bars . This results in the bulky profiles that characterise PVC windows as well as opening the door to issues with thermal bridging .

Bonded windows , on the other hand , do not rely on the strength of the sash to support the glazing – in fact the situation is reversed : the glazing supports the sash which ends up functioning as little more than edge detailing . In the same way that bonded windscreens contribute to the structural integrity of a car , bonded windows will function as a structural element within a building .

The consequence is much greater freedom for designers to increase

the glass to frame ratio , maximising the availability of natural light and allowing for lighter , less obtrusive windows . With the trend towards fully glazed walls in houses and expansive picture windows in contemporary apartments , a technology that allows for greater freedom in the design of these elements is immediately attractive . I think it is the appeal of this design freedom that has led to the rapid rise in uptake of bonded window technology in Europe . Since the first bonded windows were introduced in the 1990s , we have seen the system adopted widely particularly in the Northern European regions of Scandinavia and Germany . The latest available figures suggest that some 28 million bonded windows are installed in Europe each year .

It could be argued that the UK market is sometimes slow to adopt innovation and in this aspect , we are certainly behind the rest of the continent . However , I

do see a distinct change in focus from the systems houses and window designers selling in to this market . It is clear that the emphasis is on reduced profile size and towards lighter , less obtrusive windows and doors that allow for greater flexibility for the building designer .

For this reason , I think that the market is now ready for bonded windows and the rewards could be huge for the first companies to take up the technology . Experts from our European operations are on hand to advise new entrants with the benefit of twenty years ’ experience of bonded window technology behind them .

For independent fabrication and installation companies , the Sikasil AS66 adhesive is supplied in a battery-operated gun that can be used both in production and on site . For the volume window manufacturer Sikasil WT 480 is the adhesive designed for use in fully-automated window manufacturer with the promise of cost reduction and improved window performance .