Building Bridges From Plastic Shampoo Bottles

Dec 23, 2011
Originally published on December 23, 2011 12:37 pm
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You know, those used plastic bottles that you throw in the recycle bin, you know, shampoo, milk, juice, laundry detergent - where do you think they go? No, they're not like the socks, they don't get lost somewhere. One way they're being reborn is a sort of hard plastic lumber. Maybe you've seen them on park benches, right? Those park benches are not really made out of wood sometimes. They're used to build bridges now. They can make bridges out of plastic bottles that are strong enough to hold cars and trains and even tanks on military bases. You can squeeze or bend or crush a plastic bottle in your hands. So how do you get those throw-out bottles to support so much weight? And what else could we build with this recycled plastic?

Well now, joining me now to talk about this is Jim Kerstein. He is chief technology officer and founder of Axion International in New Providence, New Jersey. Welcome to SCIENCE FRIDAY.

JIM KERSTEIN: Oh, thanks, Ira. How are you today?

FLATOW: How did you discover that these things will be good for making bridges and stuff out of it?

KERSTEIN: Well, you know, it really stems from the - all the bad publicity, and rightfully so, that plastics was getting in the recycling stream and more importantly in the waste stream. And we started taking recycled materials, working with Rutgers University here in New Jersey and looking for things where we could take a negative, which was waste into the environment, and turn it around into a positive, which was developing long-lasting products that reduce maintenance, reduce plant obsolescence and, you know, was really a useful thing. And so, again, in working with Rutgers and some other people, we started to advance this into railroad ties, bridges, military projects, marine projects, all that type of thing.

FLATOW: So do you actually start with the bottles and melt them down, or how did it begin?

KERSTEIN: Yeah. There's a, you know, I mean, there's now a whole collection process. Most people have some type of what we call curbside pickup, you know, where the bottles are put out and where the juice containers, detergent containers, all of that is put out curbside. It gets collected. We buy certain types of material and put it together. And, yeah, then you feed it through machinery and equipment, melt it down, and we can get it to take whatever shape we need it to, whether it's a round marine piling, an I-beam type of design, you know, interlocking tongue and groove boards, all different types of things.

FLATOW: So what do you mix it with? To make it stronger, there must be other additives, correct?

KERSTEIN: It's actually 100 percent recycled plastics. The key of the technology that Rutgers developed was to put together certain materials that are strong and rugged and tough but that might not be stiff enough on their own, and mix them with other materials that are - other plastics that are very stiff but might be too brittle on their own. And in the right proportions and through the right processing techniques, they yield all types of - all types of combinations. We have 13 patents or patents pending that we work with here. And as you mentioned at the beginning of this segment, we built bridges that hold 130-ton railroads and railroad cars, M1 Abrams tanks for the military, that type of thing. It's really pretty exciting stuff.

FLATOW: Hmm. So there is a bridge in Maine, which I think - given the weather, you know, and - because it's made out of plastic, I imagine it holds up to road salt and corrosion and things - and rust much better than a steel bridge.

KERSTEIN: Well, that is one of the beauties of this stuff. It's basically got an indefinite life span, which as I said before is a real negative if you're burying it or dumping it out to sea, as has been done way too often. But it's a real positive if you're using it to cut down on maintenance and increase the longevity of products and designs. It's pretty - again, that's what makes it exciting for us.

FLATOW: Is it the same stuff that we see on the picnic tables and the park benches?

KERSTEIN: Not really. You know, just like there's different types of wood and Ipe from a rainforest is not the same as southern yellow pine, composite building materials are - have various formulations. Hours of formulations are designed specifically to impact infrastructure projects and allow us to do long spans and create the type of stiffness and strength that's needed to do bridges and marinas and that type of thing. It's not a negative reflection, I'm thinking like park benches and picnic tables. That's great recycling. But it does not have the same type of properties that our materials have.

FLATOW: 1-800-989-8255. Let's go to Jim(ph) in Tuscaloosa, Alabama. Hi, Jim.

JIM: Hi, how are you doing?

FLATOW: Hi there.

JIM: My question was - I was wondering if there was any evidence for deleterious health effects that might be estrogenic or carcinogenic from many compounds that leak out of the plastic, especially, when - in long-term structures that are put in water, where those compounds might leak out into the water?

KERSTEIN: It's a great question, Jim. There are, you know, so many different types of plastics out there. The ones that we use are nontoxic. There has been testing done where our marine piles have been driven into waterways, where formerly creosoted treated wood and things were used, and it actually allows marine life to come back into the area because there's so little impact on the environment, so little negative impact. There's a lot of positive impact.

FLATOW: Could you know we - we talk about carbon fiber a lot now and making cars and things out of carbon fiber. Could you do it with plastics? Recycled bottles instead?

KERSTEIN: Could you do a...

FLATOW: Could you make the bodies, you know, car bodies out of it - instead of carbon fibers, plastic?

KERSTEIN: You know, the potential is there, Ira, for all kinds of things. We don't put any limits on ourselves. But for right now, our focus is on, you know, true infrastructure projects that, again, are looking for real, long-term benefits of the type that we can offer.

FLATOW: Could you actually run out of plastic bottles? If you got - if this really got going in a lot of bridges, and we know how much of the infrastructure is falling down all over America...

KERSTEIN: Sure, absolutely.

FLATOW: ...could you run out of their raw material?

KERSTEIN: You know, I guess that's always a possibility, but we would be at a business level that would be so positively impacting the U.S. at that point and worldwide. I mean, right now, only about 17 percent of all plastics are actually recycled. So there's a long, long way to go before we get to that point. There's literally billions of pounds of material that are generated each year that are not recycled.

FLATOW: Let's go to Richard in New York, New York. Hi, Richard.

RICHARD: Yeah. Hi, how are you doing?

FLATOW: Hi there.

RICHARD: Yeah, I just wanted to comment. I have inspected a number of structures made out of your composite material, pilings and decking and what have you. In Staten Island there's a pier near where the Staten Island ferry comes in that was constructed. They did pile postings - I'm a diver. I do underwater construction, demolition, inspection. The product didn't stand up very low to the weather, you know, with the white (unintelligible) reinforcement roads with the black piling. Do you have any comment on that?

KERSTEIN: Oh, certainly. I mean, Richard, as I said before, you're right. I've seen those same failed projects. There are a variety of composites out there. The project that you're commenting on specifically was not one that we did. Our projects have been in service. We have bridges built for the military that go back about 14 years. We have railroad ties in service for oven a dozen years, I mean, and I'm talking here hundreds of thousands of them. So we know the longevity of our product and how it works. Again, it's like comparing different types of wood. Just because something is a composite doesn't mean it's the same as our composite. You know, we've recently won awards - R&D 100 for the top new projects of the year. And, again, we're getting reorders from customers that have utilized our product for years and years.

FLATOW: Well, what is it about your process or product that makes it so much better?

KERSTEIN: It's just the type of - it's just the material formulation. And I'm not saying that to put down any competitors or anything like that, but our material formulation was derived specifically to yield longevity and performance in just this type of application.

FLATOW: And if I'm a bridge engineer wanting to build a bridge out one of your - using your items, I don't need to know anything special or a special training or anything like that?

KERSTEIN: It's - not specifically any special training. Every material is different. Concrete bridges aren't built the same as steel. Steel is not built the same as wood. But - and so neither are composite bridges. But for instance, McLaren Engineering in this area, Parsons Brinckerhoff, Balfour Beatty, major engineering concerns have all designed with our materials.

FLATOW: All right. Jim, thanks for taking time to talk about it today.

KERSTEIN: Ira, I appreciate it. And next time, maybe I can get on not after a Nobel Prize winner, though.


FLATOW: We kept the audience for you.

KERSTEIN: Thanks. Have a great weekend.

FLATOW: Your welcome. Jim Kerstein is the chief technology officer and founder of Axion International in Providence, New Jersey. Transcript provided by NPR, Copyright NPR.