By Clark Heideger
WHEN IT COMES to Lexus’ recent advances in biodegradable, plant-based auto materials, let’s be clear about one thing, says Paul Williamsen, National Manager of the Lexus College: “We’re not talking about weaving a shirt out of hemp.” In other words, Williamsen tells me, “The end product is not a plant product. It’s a plastic, with all of a plastic’s performance characteristics.”
To anyone already driving a Lexus with soy-based seat materials or kenaf-fiber interior components, this is certainly already clear, as it will be to owners of the new CT 200h, which rolled out yet another advance in Lexus eco-plastic. This time, it’s called bio-PET, and it’s made with none other than sweet, renewable, biodegradable sugarcane. Yum.
When I spoke with Williamsen about bio-PET, he was quick to point out that, while cool in and of itself, this particular breakthrough in environmental plastics represents more of an evolution than revolution.
“We’ve already got a range of environmental plastics that we’re using, some of them for many years,” says Williamsen. “There’s actually several that we’re currently featuring in the CT 200h, and there will be more. We’ve got specific types of plastic that have to meet specific requirements.”
So the fact that Lexus continues to push the envelope beyond soy- (RX seats), kenaf-fiber- (HS 250h), and castor-seed-based car materials (HS 250h) is the real story here. Lexus just keeps adding newer and better bio-sourced automotive materials, and more of them. And in that arena, sugarcane-based bio-PET represents a major breakthrough.
You see, all plastics are not created equal. For proof of that, look no further than your recycling bins. At the base of every plastic container is the familiar recycling icon featuring a number surrounded by a triangle; each number represents a different type of plastic with different performance characteristics. And right there, at number one, is PET, albeit minus the “bio” (we’ll get to that in a minute).
OK, so what is PET, you may ask? In simplified terms, it’s a durable plastic formed with unrenewable petroleum-sourced monoethylene glycol. Chances are you already know it well in the form of your friendly neighborhood water bottle, which is at least recyclable.
So, to add a little “bio,” or renewable-sourcing to the durability equation, Lexus’ bio-PET plastics replace the petroleum-sourced monoethylene glycol with biological raw materials derived from sugarcane.
Up to this point, Lexus has limited its use of previous environmental plastics, such as those made with kenaf fibers, primarily to secondary underlying structural applications that are not seen or felt. In the CT 200h, however, the sugarcane-based bio-PET is used to line the luggage compartment, which is very much in plain sight. Not only that, but the use of bio-PET brings the CT’s overall use of ecological plastic to something like 30 percent, if you look at all CT bioplastic components like the floor mats, rear cargo deck side, and rear cargo deckboard trim, says Williamsen. And that’s still just the beginning.
“Obviously, this has a big advantage in that there is literally less of a carbon footprint when using non-hydrocarbon feedstock,” says Williamsen. “But it gets better: any time a plant is grown, it absorbs carbon out of the atmosphere. So this can actually make the overall carbon footprint go negative, in some parts of the calculation.
“And of course, all of our environmental plastics, in order to meet our requirements for use, also have to be fully recyclable, he continues.
Williamsen calls this the “triple hit” of environmental plastics: non-petroleum feed stock, plant sources that actively absorb carbon, and recyclability at end-of-life. This is also a big part of the story. Much has been made of Lexus’ commitment to make all of its vehicles 95 percent recoverable by the year 2015.
With this latest adoption of bio-PET in the CT 200h, Lexus has demonstrated that it remains committed to that goal. And keep in mind, this is a self-imposed mandate; no government agency is dictating this action. It’s Lexus’ choice. That’s why, according to Williamsen, we’ll see significant increases in the use of environmental plastics with those Lexus vehicles getting major changes in 2012, and in every major model change thereafter.
However, look for Lexus’ environmental plastics to have fully arrived when they start replacing exterior components, which probably represent the greatest challenge, subject as they are to sunlight, moisture, and heat.
“We’re working on developing new plastics for applications that we don’t currently have,” concludes Williamsen. “The whole point here is, environmental commitment is not only measured at the tail pipe or wall socket; it’s also measured in these other areas.”
- - - - By Clark Heideger
