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Biopsy for bioplastics

By Paul Gander , 02-Jan-2013
Last updated on 07-Jan-2013 at 12:08 GMT

Can we afford to use bioplastics in our packaging? Can we afford not to use them? The debate is producing plenty of heat, reports Paul Gander

Since the beginning of this year, biodegradable bioplastics have stopped receiving special treatment from Germany's regulators. The exemptions from charges levied on other materials under the country's notorious Packaging Ordinance no longer apply.

'So what?' , you might think. Chair of European Bioplastics Andy Sweetman puts it rather more elegantly: "The exemption gave our sector an important psychological kick-start, but it was never going to transform the market on its own."

While the industry puts on a brave face, the background to the decision has a significance beyond German bureaucratic wrangling.

 

Regulatory change

In the run-up to the change in regulations, the country's Environment Agency (UBA) issued a report on biodegradables that, in many ways, paved the way for their change in status. UBA product responsibility specialist Franziska Krüger says: "With their potential for eutrophication of water and acidification of soil, for example, it would be hard to say bioplastics are 'better' than conventional plastics. But they are no worse. In fact, they have the potential to be better."

She adds: "The beginning of their lifecycle, above all, needs to be made more sustainable, through the use of residual waste, reductions in energy consumption, and so on."

This was not the only 2012 report to throw down the gauntlet to biopolymers. A paper from the US University of Massachusetts-Lowell concluded that bio-based plastics, and those under development, were not "fully sustainable".

Spokeswoman for European Bioplastics Kristy-Barbara Lange says: "Many assumptions in this study were outdated." Our industry has already made "decisive progress", she argues, in the direction of good agricultural practice.

When it comes to the UBA report, Lange claims that, despite the publicity surrounding it, the report itself was "not that negative at all". She adds: "There is a clear vision to move from first-generation food crops to non-food second-generation crops. To do this in an economically-viable way, though, a bit more time is needed."

Meanwhile, bioplastics science continues to evolve. The biggest growth has been in so-called 'drop-in' replacements for conventional oil-based polymers, such as bio-polyethylene and bio-polyethylene terephthalate (bio-PET). This has gone hand-in-hand with a new emphasis on the use of renewable resources rather than biodegradability. The UBA goes as far as to suggest that the vast majority of bioplastics should not be biodegradable or even compostable, but recyclable or, as a last resort, used as fuel for energy-from-waste.

But new technology offers more sophisticated applications of biodegradable polymers such as polylactic acid, whether through the use of nanomaterials or combination with other barrier biopolymers such as polyglycolic acid (PGA).

Sweetman, who is also Innovia Films' business development and sustainability manager, points to the ways in which biodegradable and compostable laminate structures have come on over the last five-to-seven years. "A laminate with a vastly improved moisture barrier would be half the thickness," he says. "As well as biodegradable adhesives, we have metallisation techniques for our own Natureflex films, for instance, and thin film coating for barrier."

Finnish research centre VTT recently developed a technique for producing PGA from forest industry waste. With a strong gas barrier similar to ethylene vinyl alcohol (EVOH), biodegradable PGA is commercially available, says research professor Ali Harlin, but none is yet produced using renewable resources.

Definitions of sustainability

VTT is targeting the gas barrier requirements of the modified atmosphere packaging market.

In response to the criticisms levelled against bioplastics Harlin asks: "Which products are fully sustainable?" For scientists such as him, it is the longer-term unsustainability of oil-based polymers that drives continued research into renewable resources. "If I can replace 5kg of oil with 800g of sugar or waste biomass as the raw material for my packaging, why wouldn't I?"

Sceptics might respond: "Because of the cost." But then, scaling up and bringing costs down is no overnight process. In fact, it is one some might expect national governments and EU policy-makers to support. So far, the EU has not shown bioplastics the same favour it has shown biofuels. Support so zealous, says Sweetman, that it "risks market distortion".

According to European Bioplastics' figures, Europe and the US shared one third of global bioplastics production capacity in 2011, with South America and Asia holding the remaining two thirds. As early as 2016, it predicts, the latter two continents will be home to 90% of global capacity.

"Europe and North America started this," says Sweetman. "But we could get left behind."

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