Are bioplastics the complete green package, after all?

Rachel England
Monday, September 26, 2016

Bioplastics have come a long way since they were first marketed more than quarter of a century ago. What once began as a niche product with a very limited scope of application has burgeoned into a range of materials with properties that can be utilised by a variety of markets.

As such, the term ‘bioplastics’ is a broad one, and often confusing to the end consumer. Bio-based polymers refer to a material that is derived from a readily renewable source – such as corn or starch – instead of fossil-based sources, such as the plastics we traditionally know. Biodegradable, meanwhile, refers to materials that are compostable once they’ve fulfilled their packaging applications. But one quality doesn’t always precede the other; bio-based materials may not be suitable for composting, while biodegradable materials may still come from a petroleum-based source.

Going green

Their environmental credentials can be impressive, and address the growing number of sustainability challenges posed by our resource-hungry planet: biodegradable materials break down faster than traditional plastics – which can take thousands of years to disappear – and create fewer greenhouse gases in the meantime; they significantly reduce demand on rapidly-dwindling fossil fuel supplies; and in many cases they require less energy to manufacture – according to biopolymer manufacturer NatureWorks, making polylactide acid (PLA) saves two thirds of the energy needed to make traditional plastics.

Over time, bioplastic in all its forms has found its way into the mainstream market, not least for CSR purposes. Heinz and Coca-Cola have worked together on packaging collaborations encompassing plant-based materials; cleaning product company Seventh Generation has recently launched a new detergent container composed entirely of recycled and bio-based materials; and Danone has been leading the bioplastics charge with its yoghurt packaging since 2011. 

“Many bio-based materials perform in the same way as standard oil-based materials,” says Andy Sweetman, marketing manager at packaging manufacturer Futamura. “PLA, for example, looks and behaves just like polyethylene and polypropylene and is now widely used for food containers. Biodegradable materials, meanwhile, are often more permeable to moisture, but this is an advantage for many applications, such as fresh produce and items with a short shelf life. There’s little performance difference between bioplastics and traditional petroleum-based plastics.”

No technical challenges

Indeed, according to a study by Industry Arc, it’s anticipated that bioplastic is almost 90% capable of replacing all existing conventional plastics, and as Sweetman notes, widespread adoption of such materials should prove straightforward for printers and manufacturers. 

“These materials have evolved in such a way that they’re designed to operate on conventional machinery. With bioplastics you can print on the same machines, laminate on the same machines and packing machines work exactly the same. We are starting to see bio-based and biodegradable ink systems becoming available, but generally speaking conventional ink systems work just as they would with traditional plastics. In this sense, it’s really not difficult for manufacturers to adopt bioplastics.”

Chicken and egg

Yet, while the worldwide production of plastic sits at around 300 million tonnes, the production capacity for bio-based plastics is estimated to be around 1.7 million tonnes – just 0.6% of the total market. Production of plastics that are both bio-based and biodegradable is just 700,000 tonnes.

With such a potentially seamless transition to these materials on the cards, and their apparently strong environmental benefits, why do bioplastics remain such a relative non-event on the packaging landscape?

In a word: cost. According to Ryedale Group’s operations director Steve Buffoni, bioplastics come with a price tag almost twice that of traditional plastics.

“People are interested in bioplastic but no-one’s prepared to pay for it,” he says, despite a survey from the Society of the Plastics Industry suggesting consumers would be prepared to pay ‘a little more’ for a bioplastics product. “It’s a very price sensitive market. On the jobs we produce, plastic content comprises about 50% of the cost. If that went up to 75%, it would become unfeasible for many customers.

“With what’s happening with shale in America, the price of oil has gone down, which makes traditional plastics cheaper. The differentiation between traditional plastics and bioplastics is getting larger, which is holding development back.”

It is, Buffoni says, a ‘chicken and egg’ situation. Prices will come down when production volumes go up, and volumes will go up when prices come down. Sweetman agrees, while remaining optimistic that “scaling up is on the horizon”.

“The industry is open to these materials,” he says. “Where we see the most success is when the packaging meets the brand ethos of the product – organic and natural foods for example, where conscientious buyers are prepared to pay a little more for a product that fits their criteria.

“We are also seeing a resurgence of interest among retailers and brands whose selling points hinge around sustainability. They have to find ways to boost their environmental credentials without simply light-weighting packaging, and using bioplastics is one way of doing this.”

Questionable sustainability

Rather ironically another factor hampering growth is the very nature for which it is known: environmental benefit, or rather, its incredibly complex environmental impact. This year’s Innovation Takes Root event, a biennial in-house convention of those in the business of packaging made from renewable resources, saw a number of uncomfortable truths discussed.

During her address at the convention, Sokhna Gueye, Nestlé’s packaging environmental sustainability specialist, acknowledged that bioplastics are by no means a truly green material. “When compared to conventional plastics, bioplastics do have the potential to reduce greenhouse gas emissions and save on non-renewable energy use. When we also look at the agricultural production side of the equation – fertiliser use, the effect of pesticides on animals, and water use – bioplastics mostly produce more greenhouse gases, not less.”

She added that bioplastics also raise a number of questions around end-of-life compostability and biodegradability.

“Today there is limited availability of composting facilities. Even where they exist, compostable packaging is not necessarily accepted by the market. As a global brand, the great challenge is that we can’t put compostable material into markets and tell our consumers it is compostable, because that is not necessarily the reality at end of life in their country. If they don’t have the schemes or means to compost, we cannot claim the benefit.

“Even then, composting is not necessarily the most appropriate end-of-life option, compared to other options like recycling, direct fuel substitution, or incineration with energy recovery. Composting frequently brings less environmental benefits than some of these options.” 

Despite marketing campaigns to the contrary, then, the environmental benefit of bioplastics is not clear cut, and as such the industry is understandably reluctant to invest in a material overshadowed by so many question marks. But there are promising advances being made.

Looking ahead

Confectionery company Mars has been involved in a four-year research and development programme with Rodenburg Biopolymers to produce a bio-based film for its chocolate bars, hoping to switch to a packaging material that not only delivers a lower carbon footprint but satisfies the primary specification that its sources do not compete with food or animal feedstock chains. The material base for the compound, which is a starch derived from waste potato peelings, took four attempts to perfect. Although the material has yet to be launched into the European market, it’s been proven at commercial production speed and tested at select retail locations.

Access to raw materials can be challenging for the bioplastic industry – crop quotas can change suddenly and even places such as China have seen a tightening in this area – but there’s innovation here, too. 

Life sciences company Biotech has been working on a ‘biorefinery’ concept. Here, microbial strains are developed that can ‘eat’ green waste (such as wood residues) which are cheap and widely available, and from the waste key chemicals are produced that can later be used for a wide range of applications, including plastics. Similarly, companies such as US-based Metabolix have managed to produce polyhydroxyalkanoates (PHAs) from bacteria at an industrial scale, which in theory could be used in food packaging and other disposable products, such as nappies. 

As the environmental agenda increasingly takes a central role on the global stage, the issue of plastic – and the resources, waste and natural impact associated with it – will gain traction and it’s inevitable that bioplastics – an industry estimated to be worth a potential £76bn – will reach a tipping point that sees them assimilate into the mainstream. But for now, burdened by environmental complexity and ever-cheapening oil, it seems bioplastics are set to have some difficulty competing with petrochemicals for the foreseeable future. 

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