| Let's start with a question on sport! What is the | | | | Warming are causing a major re-think by leading |
| common denominator between squash, fishing, | | | | specifiers, architects and designers. Initiatives by |
| golf, skiing, tennis, motor racing and pole vaulting? | | | | International Government's to reduce fossil fuel |
| All of these robust activities rely on the best | | | | burning and the generation of greenhouse gases, |
| equipment to achieve maximum performance. | | | | through improved thermal insulation, are also |
| That equipment relies on FRP's to deliver those | | | | making the entire building industry re-evaluate the |
| results. | | | | products being used today in order to improve |
| You might know them better as 'Carbon Fibre', | | | | thermal performance and longevity. Events as |
| 'Graphite', 'Fibreglass', 'GRP' or just 'Composite | | | | recently as the Montreal Conference in December |
| material'. However, it all means effectively the | | | | 2005, to ratify the Kyoto Protocol, at which even |
| same. Fibre reinforced polymers (FRP's) combine | | | | the USA finally agreed to take the reduction of |
| two very strong materials to form an | | | | CO2 emissions as a serious necessity, emphasises |
| astonishingly tough and durable compound that | | | | that only by a common unified effort by |
| combines light weight with outstanding strength | | | | everyone in their own personal sphere of |
| and performance. | | | | influence can we collectively have any effect. |
| Thermosetting resin is a tough and durable | | | | Each of the incumbent window frame materials |
| compound whose chemical curing process cannot | | | | used today, is a growing cause of major concern |
| be reversed by the subsequent application of | | | | for specifiers, from an environmental viewpoint:- |
| heat. Therefore it cannot soften or melt under | | | | * PVCU releases the ozone depleting greenhouse |
| even extreme conditions, unlike thermoplastics | | | | gas, chlorine, during manufacture and the end |
| (e.g. PVCU) whose thermal curing cycle will be | | | | product is a poor thermal insulator due to the |
| reversed upon the application of heat, at any | | | | essential metal reinforcement inside, which acts as |
| stage of its life. This makes thermosets inherently | | | | a cold thermal bridge. |
| stable, dimensionally, in their own right - but with | | | | * Aluminium has a high 'embodied energy' from |
| the binding and strengthening addition of glass or | | | | the original bauxite mining and then the enormous |
| carbon fibres, the overall result is one of | | | | heat of the smelting process essential to its |
| extraordinary durability and performance. | | | | manufacture. The resultant end product is a very |
| Whilst Sports Equipment Manufacturers, as well as | | | | poor insulator since aluminium is, ironically, an |
| the Motor and Aeronautical Industries have been | | | | excellent conductor. |
| quick to appreciate the advantages of this | | | | * Hardwood used is invariably 'Mahogany' which |
| material, the UK Building Industry has not. In fact, | | | | only grows in the World's dwindling Tropical |
| to encourage its greater usage, the Building | | | | rainforests (the lungs of the World) which already |
| Research Establishment (BRE) at Watford, set up | | | | need protection from over zealous deforestation. |
| a specific department (NGCC - Network Group | | | | Once again, the end product does not insulate too |
| for Composites in Construction) in 2001, to | | | | well and also creates the need for regular |
| promote the use of FRP's for all kinds of external | | | | maintenance which itself has environmental |
| applications, whether structural or not. Since then | | | | consequences. |
| there have been numerous projects undertaken | | | | * Softwood does come from a sustainable source |
| which demonstrate the enormous possibilities and | | | | but the maintenance implications are appalling, both |
| benefits. | | | | in terms of financial cost, as well as |
| Examples include:- | | | | environmentally, from countless teams of |
| * The entire roof of the Millennium Dome (one | | | | maintenance engineers driving around to survey, |
| million square feet, one kilometre circumference) | | | | paint and repair windows, in an attempt to stop |
| is fibreglass. The World's largest covered | | | | them from biodegrading prematurely. |
| structure. | | | | It was, of course, to put an end to this continual |
| * The heat resistant nose cone on the NASA | | | | maintenance, in the mid 1980's, that PVC windows |
| Space Shuttle is FRP. | | | | were introduced in the first place! By comparison, |
| * A footbridge over the Barcelona to Madrid high | | | | pultruded fibreglass is nine times stronger than |
| speed rail link has won a prestigious design award | | | | PVCU thus requiring no metal reinforcement, nor |
| and is 100% GRP. | | | | suffering the resultant cold bridging. It is stronger |
| * The entire lorry cab, most motor cycle fairings | | | | than steel and aluminium, weight for weight and |
| and all TVR sports and Formula 1 cars - all have a | | | | bends less easily than either; it is non-toxic in |
| complete 'composite' body shell for strength and | | | | manufacture and inert thereafter; requires zero |
| light weight to give maximum performance - and | | | | maintenance - and insulates especially well, typically |
| no corrosion. | | | | achieving 'U' values of 0.9 - 1.5 W/M2K. Life |
| * Even the new Boeing 787 will use FRP | | | | expectancy is 50 - 75 years. Co-efficient of |
| nano-composites for 94% of fuselage and wings, | | | | expansion is negligible, being similar to glass itself. It |
| according to Russell Maquire, Boeing's Technical | | | | is indestructible by natural forces and cannot |
| Vice President. | | | | biodegrade. Upon disposal it can be ground down |
| So, clearly this is a material with enormous | | | | and used as a filler in concrete, since the glass |
| potential, not to be under-rated! And, of course, | | | | fibres improve the binding capability of the mix. |
| not to be categorised as merely "plastic", which is | | | | Cost: New technology products invariably cost |
| an incorrect broad brush generic. High technology | | | | more in order to help recoup some of the |
| plastic composites like this are at the cutting edge | | | | extensive R&D initial development costs that |
| of modern materials - and significantly out-lasting | | | | created them. However, it is reasonable to |
| and out-performing other traditional materials used | | | | expect that there should also be some practical |
| today in many external building applications. | | | | advantages to offset this higher cost. Fibreglass is |
| Manufacturing processes have also developed in | | | | no exception:- |
| tandem with the material development, to further | | | | * A formal Whole Life Cost study undertaken by |
| exploit their advantages. Whilst flat pressing and | | | | BRE has shown that the longer life expectancy of |
| moulded shapes had become common-place by | | | | Pultruded Fibreglass, over PVCU, makes it better |
| the 70's and 80's, another challenge was being | | | | 'value' over the 30 year period of the study, even |
| addressed, namely, the production of fibreglass in | | | | though the initial capital cost is higher. Additionally, |
| long continuous lineal lengths for various | | | | fibreglass has a further 20 - 45 years of life |
| applications, including window profiles. This required | | | | remaining, whilst the PVC has already had to be |
| multiple strands of glass fibre rovings and | | | | replaced - and may well have to be again during |
| continuous matt to pass through a die together | | | | the life of the fibreglass alternative. |
| with the viscous thermosetting polyester resin. | | | | * Despite the performance, environmental and |
| PVCU window profile is formed by pushing the | | | | thermal advantages of Fibreglass over aluminium, |
| liquid thermoplastic out through a die in a process | | | | it invariably offers an actual reduction in cost over |
| known as 'extrusion'. With fibreglass, however, the | | | | most like for like aluminium window designs, |
| strands can only be pulled through from the other | | | | despite the significantly lower insulation U values |
| side, hence the process is known as 'pultrusion'. | | | | and longer life. |
| The resultant end product has represented the | | | | This concept is no longer embryonic but is |
| latest in plastics technology for external building | | | | commencing in full production on both sides of the |
| components, since the late 1990's in USA and | | | | Atlantic. For example, in USA, fibreglass has |
| Canada - and since the early 2000's in UK. | | | | become the 'window of choice' for the high end |
| Pultrusion Technology Fenestration | | | | residential market and the fastest growing |
| For over 25 years, there has been little change in | | | | material in the Commercial sector. Reflecting this, |
| window frame materials with timber, PVCU and | | | | the two leading timber window manufacturers |
| aluminium dominating all market sectors and | | | | have both invested heavily in this 'new' technology |
| fulfilling most applications, whether for housing or | | | | and built huge 200,000 sq feet production plants |
| commercial projects, refurbishment or new build | | | | dedicated solely to pultruded fibreglass windows. |
| However, Climate Change, environmental | | | | Clearly, this product is here to stay! |
| concerns and the consequences of Global | | | | |