Evergreen's magic touch makes carpets 'immortal'

AlliedSignal and DSM have started work on a new joint venture project to turn nylon-6 carpet fibres back into their raw material, caprolactam. The joint venture, called Evergreen, will handle 200 million lb/yr of old carpets once it starts up late next year.

'We can make a nylon carpet live forever,' enthuses Evergreen general manager Dave Mezzanote. 'We can take a carpet, throw it into our recycling process, recover the base chemical and make a brand new car part. And if we didn't tell you, you'd never know it was a recycled product because it has the same aesthetics and performance of nylon made from scratch.'

According to AlliedSignal, the two firms' research departments have discovered a 'magic formula' to convert nylon 6 to caprolactam; although DSM's senior process engineer on the project, John Stonehouse, vouchsafed to PE that the 'magic' is, in fact, simply relatively high-pressure steam. 'It's really just the reverse of the polymerisation process; there isn't even a catalyst,' he admitted.

The most difficult part of the process is actually the collection of the old carpets, says Stonehouse. 'We're certainly not driving trucks down the streets picking up stuff as it's thrown out,' he says. Instead, AlliedSignal has forged a series of links with the US's largest carpet retailers, who send on the old carpets that their fitters collect to Evergreen. 'We're concentrating on the major metropolitan areas,' says Stonehouse.

The plant, sited in Augusta, Georgia, will produce around 100 millionlb/yr of high-quality caprolactam. According to DSM Chemicals, North America, president Bill Price, it will use some 4900 billion BTU less energy than a conventional caprolactam plant. 'That's enough to heat 100000 medium-sized homes for a year.'