Putting issues to bed - recycling mattresses

Materials World magazine
,
2 Oct 2011
mattresses

In chastening times, why make mattresses redundant when they can be put to work in cement kilns and plant membranes? At the recent Materials KTN Mattress Whitewater event in Grantham, UK, delegates explored innovative methods to keep mattresses out of landfill. Eoin Redahan reports

Every hour a double decker bus zooms by. It is crammed to the seams:

‘Are all the usual punters aboard? Fibres?’ ‘Yes.’ ‘Bed bugs?’ ‘Yes.’ ‘Pocket springs?’ ‘Yes.’ ‘Hog rings?’ ‘Yes.’ ‘Organic cotton cover?’ ‘Yes.’ ‘Several nights’ urine?’ ‘Present.’

Once these buses reach the nearest rubbish dump, the driver unburdens its contents and hurries back for the next load. According to Dr Alison Prendiville, of the University of Arts, London, about seven million mattresses go to UK landfill each year – or, a double decker bus-load every 45 minutes.

This number of mattresses going to landfill makes unsettling reading, whether they are conveyed by double decker bus or Olympic-sized swimming pool. She added that there could be 215,000 tonnes of mattresses in UK landfill by 2016. With this in mind, a group including manufacturers, retailers, landfill operators and recyclers met in Grantham to address the problem.

Seamless transitions

‘One of the things we’ve lost today is that things are more disposable,’ lamented Prendiville. In bygone beds, sea grass, straw and feathers comprised mattresses that were built to last. Stephen Ward of bed manufacturers Hypnos Ltd, based in Princes Risborough, UK, echoed Prendiville’s sentiments, ‘Wool or hair can last 100 years or more, if treated properly,’ he added.

Nowadays, ephemeral £50 mattresses are used and abused by students. As delegates spoke, these beds were busy accommodating maggots and mould in rubbish dumps across Britain. However, with the growing scarcity of raw materials, rising landfill tax and stringent Government recycling targets, bindle-shouldered maggots are increasingly looking for new homes.

Some organisations have taken a retrospective look, whereas others have adopted newer methods to streamline operations.

TWI Ltd/Silentnight Bed in Barnoldswick, UK, peered into the depths of its own process to improve operations. Project Leader Joanna Lewis explained that £100,000 of textile waste was generated from textile off-cuts alone, which the company has attempted to alleviate using a novel ultrasonic welding technique. ‘We use an off-cut piece as the backing to create a new border. This method creates a stitch-like impression. Once placed in the mattress, you can’t see the joins,’ Lewis claims, adding that the stitch-like effect produces improved end-of-life disassembly.

At Hypnos, they are recycling mattresses as a fuel source. After the steel and wood have been separated, everything else is used to create pellets for cement kilns. Ward explains, ‘Foam is a great material, but its end-of-life [use] isn’t great’. While many organisations look to reincarnate materials for a second life as a mattress, the reality of a sodden, soiled mattress often militates against this approach. ‘There’s not a lot that can be done to it from a health and safety point of view,’ one delegate noted. ‘Sometimes, all you can do is make pellets out of them.’

JBS Waste Management Ltd in Telford, UK, applies its recycled fibre in underlay for foam products, and is looking to reprocess the mattress fibre into PET bottles and polyester-based products. Using a mixture of bespoke equipment and a manual sorting process, it claims to have deviated 327,000 mattresses from landfill last year at a 100% recycling rate. Each material goes into an individual stream, and is sold accordingly, for example, the tensile steel used in mattress corners can fetch about £250-260 per tonne. However, while Operations Director John Neill ascertained that only about 200 mattresses had to be returned last year, it would be naïve to think it is always a smooth process.

‘The biggest problem is that no mattress is the same,’ he says. ‘You can spend more time recalibrating your machines than on recycling the mattress.’

In a similar vein, the London Borough of Lewisham has experienced considerable success in sidestepping landfill with a free mattress-recycling scheme. Waiving the collection fee (about £8.50 in other boroughs), they collect around 400 mattresses every week. The foam is used for insulation, metal is reprocessed and the felt, polyester and cotton are used in textile applications. However, processing can be laborious and time consuming. Strategic Waste & Environment Manager Sam Kirk said the process often involves ‘men with knives slashing the mattress into different bits’.

Rip service

The difficulty of disassembly and the diversity of mattress type were exemplified when delegates split into three groups to take mattresses apart.

With Stanley knives, clippers and scissors, they scythed through mattress layers in a trial of disassembly that elucidated the problems besetting recyclers. For 25 minutes, Neill tussled with a row of pocket springs from a king-size John Lewis mattress (which contains 600 pocket springs) as others ripped stitching and extracted each of the 100 diminutive hog rings. ‘One full size king-size mattress takes four to five hours to complete, if you’re lucky.’

However, while disassembly is timeconsuming, the replaceability of pocket springs is preferable to many manufacturers. ‘With spring beds, if one of these things gets damaged, you can pretty much write off the whole thing,’ Neill claimed.

Disassembly also revealed a few superfluous design elements that are arguably consumer driven, such as air vent holes and excessive foam depth. While the efficiency of air vent holes can be negligible and added foam depth is not said to add comfort, manufacturers are often at the behest of customer perceptions. One delegate cited the example of a mattress’ naked appearance in affecting customer choice: ‘Manufacturers spend millions and millions to sell a mattress that looks good, and then it will be covered. It’s crazy, but it’s what sells.’

Springing forth

Tweaking customer perception was prominent among delegates’ concerns in the day’s final brain picking session. Delegates were asked how a redundant material could be recycled towards a second life as a mattress and how mattress materials might be used for alternative applications.

In the former, a slew of suggestions were mooted, including creating a replaceable, cleanable cover and using materials with antimicrobial properties (such as bamboo) to help protect against bed bugs. Delegates also suggested incorporating an up-front charge for disposal, adopting an almost legotype composition for improved disassembly, and even a rent-for-life scheme, whereby manufacturers would refurbish mattresses every few years.

An alternative approach to material selection was investigated. Engineering new steels for springs to promote longer life, using alternative spring shapes for economical material usage, and examining alternative spring materials such as water, air and gel were also suggested.

In relation to alternative material use, it was suggested that foam could be used as acoustic insulation and that a modification of the fibre’s chemical properties could enable re-use instead of shredding the material. More audacious uses were also suggested as tired minds became more elastic. Delegates suggested using mattress spring beds for concrete reinforcement and habitats for marine life, as wadding for growing plants and in sports protection equipment.

One delegate even toyed with the idea of applying mattress springs in festive baubles.

After all, a mattress is not just for landfill. It can be for Christmas, too. 

Further information

www.materialsktn.net