The chronic shortage of soft coated glass before Christmas prompted the question – What are the relative merits of hard and soft coated glasses as a solution to Document L? David Offland, Joint Managing Director of Float Glass Industries, explains.
In order to identity what is the best product for any given company it is important to consider what that company’s customers want or need. The WER’s main benefit is an opportunity to differentiate ones offering from another as any thermal benefit does not really translate into significant financial savings.
Pilkington has a number of advantages over the pack. K is the market leader and is the most competitively priced product available. There are no capacity issues and when KOW is combined with Optiwhite, customers will get the clearest windows without the darker tinges associated (allegedly) with other Low E glass. No special edge deletion or toughening equipment is required and the glass is very durable. Additionally Optiwhite is a cost effective alternative to warm edge bar and there is a strong market benefit to selling ‘Energikare’ units.
Planibel A from AGC has been the talk of the industry as it is a hard coat which performs as well as a soft coat and better than K in terms of window energy ratings. On the downside the product has been accused of being ‘too dark’ but on the upside does not require any special equipment to process and toughens quicker than any other coated glass due to its special polished coating which can be toughened coated side down.
Planitherm Total Plus has been the runaway success story over the last year or so. This product has the best performance as far as WER’s go and is very durable for a soft coat. It does, however, require edge deletion and is slower to toughen that the hard coats. The product does have a shelf life and is susceptible to surface damage more than the hard coats.
Planitherm Total Plus is the only soft coat to be manufactured in the UK and has achieved record sales whilst still charging a premium price. St Gobain claims the product still represents value for money as it does not need to be combined with Low Iron Glass to achieve a C or better. It remains to be seen how much of an own goal St Gobain have scored with their production problems and inability to supply key clients in the last quarter of the 2010. Clients may choose a lower spec, more reliable product going forward.
There is also an argument that Planitherm Total Plus is over spec’d and is not required just to achieve a WER pass.
Arguably Guardian could be the biggest beneficiary of St Gobain’s production problems. Climaguard A is a cost effective soft coat which performs slightly worse than Total Plus. Unfortunately Guardian has no coater in the UK and therefore the UK operation is at the mercy of its Luxembourg Plant. Guardian UK could not benefit from St Gobain’s inability to supply in the last quarter of 2010 and was restricted to a paltry 50 loads a month from the continent.
There is no doubt that Guardian will improve its Climaguard A so that it will perform as well as St Gobain’s Total Plus given time. Climaguard A is also competitively priced and will be a real player when Guardian decide to put a coater down in the UK. Disadvantages are that the product requires edge deletion, has a shelf life and is slower to toughen than the hard coats and especially Planibel A.
The question is will the market sacrifice a small amount of performance for reliability, processability and price? Only time will tell. In the meantime, all these products are available in stock and toughened form from Float Glass Industries on stock or toughened form.