Introduction
The commercial carpeting market is the scene for some of the fiercest competition in the construction products industry. In the search for an edge, the more agile manufacturers are reacting to prompts by specifiers and government agencies to produce carpet tiles that significantly reduce their environmental impact.
There are two main concerns – one is the potentially toxic emissions to air during the installed life of a tile, and the other is the quantity of used carpet treated as waste.
Toxins such as styrene, formaldehyde and xylene can be harmful at low levels, but improved detection technology, more stringent performance standards and new materials bring the prospect of a healthier working environment.
The amount of carpet waste we bury is staggering – it’s estimated that about 165,000 tonnes are sent to landfill in the UK annually, and worse still, much of it has not reached anywhere near the end of its working life.
The obvious solution is to re-use when possible – suitable tiles are collected from site, graded and sold back into the market. Sadly, progress in this sector has been disappointing - whilst feasible, in practice and without critical mass, choice is restricted and recovered quantities unpredictable. For refurbishment to work in the future, manufacturers need to become re-engaged and to commit greater resources.
In contrast, the recycling of carpet materials has been the subject of substantial capital investment. Ideally, at the end of its working life the tile can be returned to the manufacturer where its components can be disassembled and returned to the production stream to form new carpet – this ‘cradle to cradle’ concept is the most virtuous form of recycling.
Specification issues
Allegedly, flooring products account for around 40% of a building’s environmental impact and soft flooring will be changed between 6 and 12 times during the 60 years of a building’s life. Whatever the source of these figures, they are a useful prompt to consider the importance of specifying products such as carpeting with an eye to minimising environmental impact.
Perhaps the most important consideration is to reduce the frequency of carpet changes. Carpets are changed for two main reasons – fashion and wear. Not a lot can be done about fashion, though clearly linking carpets with the design ethos of ‘de jour’ is inviting instant obsolescence; but plenty can be done about wear. By specifying carpets that have durable qualities through their construction, their protection from soiling and their suitability to undergo cleaning regimes, the designer can go a long way in achieving the low impact goal.
Carpet tile construction varies greatly in materials and sustainability. Because of the high performance expectations, commercial wearing layers have traditionally been made using nylon, and only lately have alternatives begun to emerge. Though the most obvious, the wearing layer is usually surpassed by the backing layer in terms of environmental impact. Some manufacturers continue to use the earliest type bitumen formulas for backing materials, but most will use PVC which was developed to replace it – providing reduced weight, improved stability and ease of laying. PVC itself is becoming eclipsed by some manufacturers eager to reduce PVC’s impact – replacing it with arguably superior materials include PET and polyolefins.
Apart from selecting a durable carpet composed of materials with minimal environmental impact, the third most important aspect is considering what happens when the carpet reaches the end of its working life. The specifier should consider to what extent the carpet can be recycled. Some manufacturers build in a recycling programme (cradle to cradle), but most currently don’t.
Carpet tile construction
Commercial carpet tile construction generally comprise of a pile fibre wearing layer, usually nylon. The majority of carpets involve yarn pile tufted into the primary backing, typically a non-woven polyester material which is in turn bonded to a secondary backing. The secondary backing, particularly in carpet tiles, provides rigidity and dimensional stability.
Image courtesy of Desso Carpets
Construction materials: the wearing layer: pile fibres
Commercial carpet tile construction generally comprise of a pile fibre wearing layer, usually nylon. The majority of carpets involve yarn pile tufted into the primary backing, typically a non-woven polyester material which is in turn bonded to a secondary backing. The secondary backing, particularly in carpet tiles, provides rigidity and dimensional stability.
Nylon
Nylon accounts for around two-thirds of the fibre used in carpets - mainly because of its durability, making it ideal for areas of high traffic. Nylon fibre is produced in two forms: Nylon 6 is the cheaper of the two, but can now match its rival’s performance. The big advantage of Nylon 6 is that it is much easier to recycle; Nylon 6.6 has a higher performance rating than Nylon 6 but it may not be enough to make a difference in selection.It is worth noting that although all nylon is easy to dye, the preferred process in terms of longevity of colouring is ‘solution dyeing’ (see ‘dyeing’ below)
