Improving mattress recycling

A bit of a thought dump on how to improve mattress recycling based on some things that I've seen in Google+ and Youtube. Most have been shared by +Gary Ray R, and a huge thanks to Gary.

Dealing with springs

Recycling mattresses best means that you are left with spring bases. These bases become problematic, because they are not particularly dense, and the spring steel can cause problems for scrap metal shredders.

Olaf Industries has come up with a baling solution for the mattresses, and Mission Australia's Soft Landing is distributing them in Australia. Have a look at the video below to see what it can do.

In case you missed the box spring dismantling, here's another video of one of those. It doesn't seem to do quite the same job as the Goodwill Industries machine.

Shredding

Then there is the option of shredding the springs. There is a pretty cool video of a shredder chomping up all sorts of things. You kind of half expect the thing to chomp up the operators - their safety guarding is not the best.

Robotic mattress dismantling

And finally, the news that got me started on all of this, the Baxter Robot. It's a robot, that's not so exciting. The exciting bit is that it sells for $22,000 (USD). I can imagine a robot cutting apart mattresses using rotary cutters in a way that may be too dangerous done by people.

Unfortunately they are not for sale outside the US.

Maybe it doesn't need to be a robot. Maybe a rotary cutter running back and forth on a rail, with the mattress turning so that each side is cut. I wonder if that could be designed up by a clever mechatronics engineer.

Recycling of mattress fabric

A former post, "How do you recycle a mattress?", described the mattress dismantling process and identifies that steel and foam is recycled. Mattress fabric is not, generally.

I've been doing some research on how to recycle this fabric. That research has indicated that the fabric is generally a polyester blend, often blended with cotton. Which led me to ask if polyester fibre is recycled.

It turns out it is, and that is reasonably high profile for companies like Patagonia (working with with the Teijin ECO CIRCLE system from Japan). There is also Repreve in the US. Both processes take post-consumer fabric and reprocess it back into polyester fibre for remanufacture.

Teijin's Eco Circle Polyester Recycling process. Source: Teijin.

These processes chemically decompose the polyester and convert it into new polyester raw material. They work for clean polyester. I think. I'd love to know if they (or other) can also work for polyester blends.

In asking the question of networks, I was contacted by Nextek and advised:

We have recently finished a project in Europe where we have successfully recycled dyed polyester fibre, stripped out dyes and volatile and also upgraded the IV of the polyester resin for closed loop recycling back into fibre applications.

It will be interesting see what comes of it, and the answer may be the subject of a future post.

In the interim, it is good to know how much work is being done to recycle polyester. This has classically been described as recycling PET bottles back into clothes, and to be honest, I could never really reconcile this. Think about how many PET bottles are discarded and contrast that with the amount of clothing made with PET - I can't imagine they are in the same game.

But taking polyester fabric and reforming polyester fabric seems much more sane. It matches life cycle, it looks to close a loop reasonably tightly. Repreve has a great summary of what their process saves in the manufacturing process. To a non-polyester expert, this all seems pretty impressive.

A summary of how the Repreve process conserves natural resources. Source: Repreve

Perhaps asking the question of what can be done with mattress polyester blends can nudge the industry into finding solutions (if they don't already exist). 

That, in turn, could could find a path for a whole heap of additional resources to be returned to the manufacturing process rather than landfilled. And, done locally, it enables every city of reasonable size to have its own polyester resource that can be used to build in all sorts of fabrics.

How do you recycle a mattress?

How do you recycle a mattress?

Well, there is the dumb way. This assumes that the springs are the valuable bit, and tosses the mattress into a shredder and pulls the shredded up steel off using magnets. Looks like this.

Mattress in a low speed shredder, image courtesy of American Recycler

You'd think that was a pretty clever way of going about it. You'd be wrong.

Sure, there's value in the steel, but there's also value in the foam (depending on markets) and the timber (to a lesser extent). Shredding the mattress destroys these elements.

It also jams up shredders. I have been to any number of "demonstrations" of new shredders that will apparently shred up a mattress. They're usually good for a couple before the spring steel clags the machine up. You want to laugh, because you knew it was going to happen, but you just feel sorry for the poor contractor who, at best, has just lost a whole heap of potential sales. At worst he's damaged his machine.

And then there's the clever way. This looks at the value of everything, including the space taken up in landfill, and pulls the mattress apart to maximise these values. It is men and women with sharp knives standing around a mattress on a wool classing tables, cutting it apart to separate out the springs from the foam from the fibre from the fabric. It looks like this:

Mattress recycling with a knife, image courtesy of MPR News

The steel obviously has a market (but preferably cut into metre square pieces so it doesn't jam the steel shredder), and the foam can go to things like carpet underlay. In Australia, the big player was and presumably still is Dunlop Flooring, part of Pacific Brands. Baled and shipped to Melbourne, it is reincorporated into new products.

Up until late last year, you could comfortably say that most Australian cities had a mattress recycler, however mattress cleaner and recycler Dreamsafe went into voluntary liquidation in November 2011. They had a lot of plants on the east coast. There are probably others.

In the west, the Eastern Metropolitan Regional Council runs one, but you can drop your mattress off at most waste facilities and they will take it to the EMRC. You'll pay $10-20 or so for the service, but seriously, for the sake of a pint or two of beer at a Perth pub, how could you not?