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ABC Radio National


abc radio national "recycle plastics to fence posts"

Radio Australia - Innovations - Recycle Plastics To Fence Posts

21 January 2008

Recycle Plastics To Fence Posts

A process to make all waste plastics useful


DESLEY BLANCH : You probably think you're doing your bit for the planet by recycling household waste like plastic bottles and cartons. But in fact, most kinds of plastic are extraordinarily hard to recycle and they end up in landfill.

Plastic in landfill can take hundreds of years to biodegrade and burning or melting it lets off toxic gases, so it poses a real quandary. A Melbourne business man has spent nearly a decade figuring out how to turn the 77-thousand different types of plastics into fence posts.

Roger Sweeney, Director of Australian Composite Technology gets plastic waste from all over Australia. He manages to reuse everything, from hard hats to car bumper-bars and mobile phone casings.

The ABC's environment reporter, Claire Gorman went to meet him recently at his production plant and just a small warning this is a very noisy field report.

CLAIRE GORMAN : Roger, we've just walked into your factory here and it's an enormous space and there's piles and piles of plastics here. What's this right here in front of us?


ROGER SWEENEY : That's geo-fabrics material, which is made of recycled Coke bottles, 99.9 per cent.

CLAIRE GORMAN : And this stuff, it actually looks like rolls of fabric, is that going to go into your products?

ROGER SWEENEY : That's correct. It's shredded, granulated and blended into our mixture for composite material.

CLAIRE GORMAN : What's making my head spin about being in your factory while we've just had a quick walk around is there's actually hundreds and hundreds of kinds of plastics here.

ROGER SWEENEY : That's right. We do just about all industrial plastics, including cross linked polymers.

CLAIRE GORMAN : How many kinds of plastics do you recycle?

ROGER SWEENEY : We've probably lost count of the actual number, but theoretically, our choice is up to 77-thousand.

CLAIRE GORMAN : Here on my right are piles of plastic in bundles. What's this here?

ROGER SWEENEY : This is a waste stream from the industrial sector which is largely polyprophylene packaging material.

CLAIRE GORMAN : So, what was this stuff of packed originally?

ROGER SWEENEY : Nuts and bolts and equipment for manufacturing lines.

CLAIRE GORMAN : Alright. Now we're just walking down here, and this is a big canvas bag and it's got some chewed up pipe of some kind in it and it's bright purple. What would that have been once?

ROGER SWEENEY : They're offcuts from the manufacture of plastic water pipe, which is replacing a lot of copper in building applications.

CLAIRE GORMAN : And, you've chewed this up ready to go into your process?

ROGER SWEENEY : That's correct. That plastic is cross-linked. It's difficult to recycle, but we've been able to find a way of doing it.

CLAIRE GORMAN : That's one of the issues isn't it with all these different plastics coming in that they are not pure plastics a lot of them. They've got say, glues on them and metals and all kinds of things?

ROGER SWEENEY : That's right. The process of recycling is becoming increasingly more difficult due to the complexities of the polymers.

CLAIRE GORMAN : And, what's this here, on our left? It looks like -- well they're very strange shaped objects. What are they?

ROGER SWEENEY : Aah, that's sprues and runners from the injection moulding industry.

CLAIRE GORMAN : What are these bright yellow things?

ROGER SWEENEY : Those bright yellow things are old chicken crates that take chickens to market once they've been put to rest.

CLAIRE GORMAN : So, say with a product like this, it might come in with blood or other things on it. Is that a problem for your process?

ROGER SWEENEY : No, we can handle the contamination and dirt and cardboard and other minor contaminations will go straight through the process.

CLAIRE GORMAN : This is a crate of what used to be mobile phones. How many of these would you get in every week?

ROGER SWEENEY : Oh, they come in by huge containers from MRI via the Mobile Muster campaign.

CLAIRE GORMAN : What are these things up there that look like Petrie dishes almost?

ROGER SWEENEY : They are trays that are used in the pharmaceutical industry for making vaccines.

CLAIRE GORMAN : So, is there a danger that there might be contamination in a case like that?

ROGER SWEENEY : No, they've been sterilised before they've been delivered to ACT. (Australian Capital Territory)

CLAIRE GORMAN : Alright, so I'm getting the idea that you've got masses of different kinds of plastic, including car bumpers and all kinds of things. What's the first step in your process?

ROGER SWEENEY : Initially, when materials are received, we size reduce it by running it through a shredding process.

CLAIRE GORMAN : And that's that massive noise in the background there?

ROGER SWEENEY : Well, it'll get noisier when we get closer to it.

CLAIRE GORMAN : This is a conveyor belt. Does this represent the beginning of the process here?

ROGER SWEENEY : That's correct. This reduces the large objects such as bumper bars down to a manageable size, for further processing.

CLAIRE GORMAN : I'm looking at the vast array of stuff you've got here. I'm wondering does anything go back into landfill?

ROGER SWEENEY : It does. Our recovery rate is for every one hundred and four 30 cubic metre skips are processed, we send one skip to landfill, so it's less than one per cent of material is wasted.

CLAIRE GORMAN : This stuff here comes from Canberra, does it?

ROGER SWEENEY : That's right. That comes from Parkwood Recycling Centre, that is all the building waste, plastics from all the building activity in Canberra.

CLAIRE GORMAN : What made you want to do a job like this, where you're actually inventing a recipe to recycle stuff that other people think is junk?


CLAIRE GORMAN : I see you smile there, but you do have some significant challenges, don't you?

ROGER SWEENEY : Well, we do. The way forward in the environment is to actually do something. You can't just sit on your hands and talk about it. You've actually got to get out. Invested in here is around eight million dollar investment and it probably needs twice as much again to make a real impact. So, I think time for talking is finished. This is part of the doing of the doing.

CLAIRE GORMAN : You must have had to put a big R&D investment in that though?

ROGER SWEENEY : We spent nine years researching it before we set up business.

CLAIRE GORMAN : What's happening here in front of us?

ROGER SWEENEY : This material is going through a granulation process to reduce it in size and then it's being re-densified back into pellets to make it usable in our process.

CLAIRE GORMAN : Is this the next stage from what we just saw?

ROGER SWEENEY : That's correct. This is the next size reduction, and in this case, because it's light plastics, it's being redensified to give it some mass, so it can be used in the extrusion process, which we will see shortly.

CLAIRE GORMAN : So this stuff coming out there that you've got in your hand is very fine?

ROGER SWEENEY : That's right, and it's very heavy, which enables it to have some critical mass to able to be blended with the other hard plastics to use in the composite process.

CLAIRE GORMAN : I was just laughing before because you've got these massive posters here of Australian Open tennis stars. What are these doing here?

ROGER SWEENEY : We do the recycling of plastics for shows like the Australian Tennis Open and these signs and posters and pictures and billboards happen to be made of plastic. It's a polypropylene and we also re-shred them. We kept a few of these as a bit of a souvenir.

CLAIRE GORMAN : So are you telling me you're going to mince up our Australian Open tennis stars?

ROGER SWEENEY : That's right and some of them should be minced up too, I can assure you.

CLAIRE GORMAN : Compared to some of your other equipment, this machine in front of us looks a little bit insignificant, but in fact it's not.

ROGER SWEENEY : It's where the excitement starts in the process.

This machine is a ribbon blender that takes all that material you've seen being shredded and granulated and blends it into the successful formula to make a fence post in a very consistent manner.

CLAIRE GORMAN : What would happen if the formula wasn't right?

ROGER SWEENEY : The post would get rejected under quality control and we'd have to shred them and start the whole process again.

CLAIRE GORMAN : And weight is important too?

ROGER SWEENEY : This machine weighs it as it goes along. It's on its own pedestal with its own scales and we can tell absolutely to the kilogram as to what blends of material are in it.

CLAIRE GORMAN : I just climbed up the ladder there and had a look in and it looks a little bit like a breadmaker.

ROGER SWEENEY : That's exactly right. Just like when you Mum made a cake. If you didn't put sufficient flour in, or too much flour or not enough currants or whatever, the recipe wouldn't come out right.

CLAIRE GORMAN : I bet you've done that a few times?

ROGER SWEENEY : Many thousands.

CLAIRE GORMAN : You've got a handful of metal there. What's that?

ROGER SWEENEY : In the system, we have ten zones that remove metal from the plastics. Even plastic that looks clean contains metal that could be as fine as a staple, but when you're putting thousands of tonnes a year through, it certainly builds up and you need to have this sort of magnetic protection gates on the system.

The metal, it damages the extrusion equipment and it's important that you remove as much of it as possible.

This is the actual machine that makes the fence post. The material that you have seen processed in our walkabout today; having been fully blended is now fed into the extruder, which injects the hot plastic into the moulds. The moulds are then carouselled into a water bath, cooled and then extracted and stacked.

CLAIRE GORMAN : In my mind, plastics have become a bit dangerous when they're heated, but that doesn't happen in your process?

ROGER SWEENEY : No, we never exceed the melting point of the various plastics.

DESLEY BLANCH : Roger Sweeney, Director of Australian Composite Technology, showing ABC Canberra's environment reporter, Claire Gorman, around his factory.

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