For plastic film to continue as the packaging industry’s most successful material, we need to be farming it in order to ensure a more sustainable future, reports Des King.
We are consuming more oil than the 87.5 million barrels per day (mbd) that we are producing. Estimates vary, but the variance could be almost 1mbd – not helped by the fact that for every new barrel we fill, we use the contents of a further four to drill for it. And with demand fuelled by the newly emergent BRIC economies not to mention a nine billion and rising population, the shortfall is sure to expand unless we tap into a massive and as yet undiscovered new source of supply.
With plastic representing less than 4% of the oil barrel, the requirements of the worldwide €50 billion flexible films market (approx. 20 million tonnes per year) might seem small beer, not to mix our liquids. Fair enough, but as resources start to dry up, the packaging industry is inevitably going to find itself not just low man on the totem pole, but not on it at all. In the interim, pricing can only continue to head one way.
The current dollar bill per barrel is marginally lower than at the start of the global recession three years ago. But it is not just determined by availability. A disruptive change in geo-politics – Iran blockading the Strait of Hormuz, for example – could easily send it straight over the $200 mark. That potential for unpredictable volatility calls for an insurance strategy, hence the growing level of investment being made by the petro-chemicals industry itself in bio-based alternatives to conventionally generated energy and its derivatives, let alone the needs of global brands, such as Coca Cola, Danone and Nestlé to secure their supply chains as well as sport their green credentials.
Growing pains
Energy and, as either a primary or by-product, plastics can be derived from sugar, starch and other more infinitely available resources than oil. Indeed, one enterprising bioresin developer, Eastern Bioplastics, has found the way to distil ethanol from chicken feathers. Estimates vary widely as to the spare capacity of rain-fed land that could readily be turned over to the production of bio-crops, but in all probability it is between 400 million and 500 million hectares.
Contrary to objections regularly trotted out by the ‘food rather than fuel’ lobby, this is not land that might otherwise be used for agricultural purposes. Indeed, the ability to feed or to starve indigenous populations is as often as not a commercial rather than a logistics decision, for example, Guatemala growing coffee for the US because of the dollars it earns rather than directing the same resource towards sowing crops for domestic consumption.
With annual biopolymer production on track to rise from 725,000 tonnes in 2010 to 1.7 million tonnes by 2015, it is enough to be going on with over the short term, not least as despite the upward trajectory of that rapid growth path, most pundits agree that bio-packaging will still only account for around 1% of the total plastic packaging market by 2020.
Fast forward to 2050, however, when it has the potential to be more like 20% and we’ll need to realign our priorities, said Dr John Williams, head of materials at NNFCC, the UK’s National Centre for Renewable Fuels, Chemicals & Materials. ‘Whilst there is sufficient land around the globe to meet our material as well as our food resources, there’s insufficient biomass land to meet all of our energy requirements; likewise for fuel.
‘Down the road, producers and users of bio-based plastics will be judged on their ability to manage sustainable supply chains. This also relies on the development and implementation of suitable assessment tools and procedures.’
It is an observation that pinpoints a growing schism within the bioplastics community: whether to be seen repeatedly or to be seen and not heard of ever again. The likelihood is that biopolymer as a spin-off from bio-fuel – and having the same capability of being recycled as an increasing number of conventional plastics – will represent the best long-term use of resource, in effect, a green interpretation of the existing script.
Here today, gone tomorrow
Meanwhile, however, most attention has been captured and in some cases hijacked by the prospect of a compostable alternative that affords no tangible end of life benefit other than eventually disappearing altogether. It is a quick fix solution that delivers a positive populist response, for example, in Italy which was getting through 20 billion conventional plastic PE bags per annum up until they were banned in January 2011.
Yes, it has put the biopolymer proposition right up there on the agenda – and enabled at least one Italian manufacturer, Novamont, to reinvest over €450 million in boost production of its Mater-Bi polymer to c.250,000 tonnes per year – but the net result has just been the elimination of an arguably over-hyped eyesore and a low-value one to boot, said Dr Williams. ‘Focusing on the plastic bag is an easy way of drawing attention to the need to consider the environment, but in reality, they probably represent no more than 1% to 2% of the waste stream.’
Even so, there is much more to litter than merely supermarket bags, points out Innovia Films’ business development and sustainability manager, Andy Sweetman. ‘What we’ll see change increasingly over the next three to five years is that the application itself will dictate the choice and/type of materials to be used.
‘If you consider all flexible packaging litter, not so much the demonised supermarket plastic bag but things like crisps packets, sweet wrappers, etc, for which there is no cost-effective and manageable waste recovery stream, then a compostable solution makes most sense.’
It is a pragmatic view that makes short-term sense at least. Why, for example, try to impose a biopolymer solution onto the plastic bottle market within which PET extending through to rPET encapsulates the optimum solution? It is a throwback to the bioplastics industry’s early gung-ho days of going for anything and everything.
It is also arguably a more fit for purpose solution than going the oxo-degradable route of accelerating end of life within a given time frame, a technology that attracts support and negativity in equal measures, having been recently adopted by the UAE to replace an estimated half a million tonnes of conventional plastic packaging per annum, and rejected last year by Tesco for use at the checkout on the grounds that it led to ‘double-bagging’.
‘You’re blending in an additive to a conventional durable polymer to allegedly make it biodegradable within a given time frame,’ said Dr Williams. ‘There’s no independent evidence to show that this happens within the parameters as claimed. It merely fragments into smaller plastic particles. I believe that what they’ll find in the UAE is that whilst there might be an apparent lack of plastic material floating around at the macro level, it’ll still be there but less visible.’
Form and function
What is holding back compostable solutions, such as Innovia’s cellulose-based NatureFlex, from resolving commodity waste issues are scale-up and a cost base that is often three times higher per raw square metre than conventional polymer, conceded Mr Sweetman.
That will continue to get closer to parity, but in the meantime is not necessarily the main issue as far as some brands are concerned as reported in the March issue of FlexoTech. UK-based confectionery manufacturer Miss Muffet & Co, which has built its business through using natural ingredients and materials wherever possible, chose NatureFlex. Proprietor Sarah Cadman said, ‘It was really important that our packaging had the lowest possible impact on the world around us […]. We chose transparent NatureFlex primarily due to its environmental credentials, but also because of its ability to keep our sweets tasting and looking good.’
That highly reassuring endorsement of functionality will resonate with converters and packaging manufacturers, whose role in the supply chain is mainly that of interested spectators, and who would be unlikely to initiate a biopolymer solution that hadn’t been expressly specified by their brand owner customers.
‘The big change over the past five years hasn’t been so much in terms of the cost base, but the technical performance,’ said Mr Sweetman. ‘We’ve now got biopolymer materials that print and laminate just like conventional films, and which have increasingly conventional barrier properties, partly achieved via metallisation, but also the development of coatings that modify the properties of its materials accordingly without compromising compostability.’
In fact, a flexo printer using NatureFlex would find it performs in exactly the same way as a conventional film, claimed Mr Sweetman. That like for like replication is equally as true for bio-based equivalents to PE and PP, which are capable of dropping directly into existing applications and more importantly, waste recovery and recycling streams.
Biopolymers – the rough guide
The ethylene customarily derived from oil that is the essential component in the production of conventional plastics has the same properties to all intents and purposes as the ethanol obtained through a wide variety of biomass sources including vegetable fats, cellulose, sugar and corn starch.
In essence, the bioplastics industry breaks down into materials produced from PLA or PHA (made of fermented corn sugar) and cellulose that are fully or partly biodegradable through composting or anaerobic digestion, etc, and those that mimic their fossil-based counterparts such as PE, PP, PET and like (and indeed alongside) them can be recycled.
In current terms, the 800,000 mt bioplastics industry is populated by over 500 different variants of biodegradable/non-biodegradable grades. As used packaging is increasingly being recognised as an asset, recyclable ‘drop-in’ bio-based materials are emerging as the preferred choice by brand owners.
By 2015, when the market will have more than doubled it is estimated that bio formats of PE and PET will represent 43% of total bioplastics production: 450,000 mt and 290,000 mt respectively, with the main concentration of sites in Asia and the Americas.
The swing towards renewable bio-based resource is anticipated to dominate within an overall growth conservatively forecast to run at 14% per annum thereafter. Whilst Braskem’s bio-PE might be currently 30% higher than the market value for the fossil-based alternative, greater scale-up will in turn impact positively upon price.
