Plastics : Food Wrapping: Can composting and biomaterials solve the plastic crisis?

While the impact of the pandemic and the increase in use and waste of single-use plastics on the plastic litter problem has yet to be fully determined, many (Western) nations are still reacting to China’s 2017 Operations National Sword, which banned the import of low quality non-recyclable plastic waste, leaving countries scrambling on what to do with their existing plastic waste.

While looking for other takers of their plastic waste, numerous countries and regions have reassessed their plastic waste production, policies, and infrastructure at home. For example, the EU published the EU Plastics Strategy, a mix of 38 regulatory, economic and voluntary measures. The goal was ambitious: By 2030, all plastics packaging on the EU market is to be either reusable or recycled in a cost effective manner.

In parallel, the Ellen MacArthur Foundation launched the New Plastics Economy Global Committment, which has since mobilized at least 500 signatories from the consumer packaged goods and plastics manufacturing industy to eliminate unnecessary plastic packaging and otherwise reuse, recycle or compost all other plastic packaging.

The scientific community, as well as international organizations, have been committing serious resources to understanding the sources and flows of plastic litter.

Plastic is ubiquitous in the economy and high tech innovation continues to spur the creation of different varieties of properties of plastic for a plethora of applications. Flexible-or single-use-plastics for packaging are produced from low density polyethylene (LDPE) or polypropylene (PP) and their properties of thinness, durability, protection, consumer appeal, to name a few, are constantly being tweaked – all while remaining convenient, versatilite and cheap. And to be used mostly only once.

The plastic packaging industry is valued at between $80 million and $120 million per year. For a visual: 1 to 5 trillion plastic bags are consumed each year, which is equivalent to 10 million plastic bags per minute.

While flexible plastic makes up 35% of all plastic produced, it makes up 50% of the plastic waste, according to UNEP. Various studies suggest that of the disposed single-use plastics, 40% is landfilled, 14% incinerated, and 32% leaked – also strewn in environment. Of the 14% recycled, 4% is lost in process, 8% recycled into lower value applications and only 2% effectively recycled according to a UNEP study. Flexible plastics are the number one plastics ocean polluter.

Many countries have stepped up their ban on plastic bags and mandates to replace other single-use plastic items with other renewable resources resulting in a decline in plastic bag use, but not without mixed results or other use of worse alternatives, depending on available alternative options, the economic status of the countries, and the presence of waste infrastructure.

At the same time plastics manufacturers have stepped in with innovation to help solve the plastic litter problem. The primary focus has been on recyclable flexible plastics, and, gaining in momentum, compostable flexible plastics.

As signatories of the Ellen MacArthur Foundation’s New Plastics Economy Global Committment, Schurflexibles, a European supplier of highly specialized packaging solutions for applications in food, hygiene, aroma protection and pharmaceutical industry, also joined CEFLEX, a „European initiative with the aim or creating an infinite resource cycle“ to „make packaging better, lighter and more sustainable“. They have also hired three full time specialists who evaluate each of their products for recyclability potential.

Technically, recycling flexible plastic seems a simple process: it involves seperating the waste products by grade (PP, LDPE etc), cleaning, drying and shredding them before mechanically or chemically recycling them, and then reselling the new specific recyclate to plastic producers. The recyclates are typically recycled to lower grade plastic products.

Schur Flexibles, has adapted their portfolio to make as many of their products as possible recyclable. From a design perspective that means: creating mono-material products (of either just PE or LDPE with) and mono-layered (with no PET or aluminum). Other design issues are adapting glue to make labels more removable, and/or ink for printing. Schur Flexibles offers two dozen products which are recyclable.

There can be, however, limitations as to how recyclable a product can be, according to Martin Berlenkamp, Sustainability Director of Schur Flexibles. He explains that in some instances recyclability reduces the overall sustainability of a product. For example, when packaging beef with a flexible plastic, knowing that 97% of the carbon footprint of the beef-and-package is related to the beef, and only 3% related to the packaging, from a sustainability perspective, the focus is on the preservation of the beef and not the recyclability of the packaging.

In addition, Berlenkamp explains that there is no universal definition of recyclability, to which they can adhere when designing recyclable products. Even in the EU, which enacted the EU Packaging Waste Directive, there is no uniform plastics recycling law in every country. As a result, Schur Flexibles designs their products‘ recyclability according to the clients‘ country’s recycling mandates and infrastructure. As a consequence, a product might be categorized as recyclable in one country, but not necessarily so in the other.

On a more pragmatic level, the real challenge with recycling flexibles plastics is not necessarily the design of a recyclable flexible plastic, but the following logistical steps needed to actually get the flexible plastics recycled. Those are after use of the flexible plastic: 1) collection of the flexible plastic waste, 3) sorting of the flexible plastic waste, 4) availability of mechanical or chemical recycling, and 5) selling the recyclate in a competitive market. Flexible Plastic Producers are aware of these logistical steps when designing for recyclability, but are not in control of them.

Regarding the actual recycling the of flexible plastic waste, mechanical and chemical recycling both come with barriers of cost, especially chemical recycling. Other barriers are understanding what materials are availabable, and how much sorting and cleaning is required.

That said, European plastics manufacturers are investing in diversifying their recycling portfolios to add chemical recycling to their mechanical recycling options. Plastics manufacturer Borealis claims to be piloting a chemical recycling plant, with the promise that they are piloting pyrolisis with the goal to create feedstock from recycled material of similar quality to that from crude oil, to provide their packaging producing clients with recyclate polyolefins of high quality.

If Borealis, the largest plastics manufacturer in Europe is still only at the pilot stage of chemical recycling of polyolefins (to make similar quality products for flexible package use), if mechanical recycling of PE and PP produces products of lesser quality, and if most plastics don’t even make it to a recyclding facility – this makes the case there definitely is still room for innovation in the recycling and thus circularity of flexible plastics.

Flexible plastics recycling to TIPA is not the solution, neither mechanical nor chemical. TIPA sees a sustainable plastic as a circular one, where the plastic is compostable and goes back to the soil as enriching organic material without leaving any foreign elements behind. The reasoning is that currently only 5% of flexible plastics are in effect recycled (some studies suggest 2% - see above), and if they are, they are reused only once. Also: according to TIPA flexible plastics make up 80% of plastic litter. (not 50% from UNEP source)

As for the flexible plastics design, TIPA adheres to the premise that much of the value of a product is that it performs well; flexible plastics typically performs better when in several layers of different materials, yet knowingly, multiple layers are difficult to seperate, therefore to sort and recycle. It makes more sense to offer a good multi-material, multi-layer flexible plastic product -that will anyways most likely only be used once and not recycled, with a stastical probability to be strewn into the environment- that, therefore, may as well just be made compostable.

Furthermore, Vincent Kneefel, Senior Director of Sustainability, explains that „44% of global waste is compostable“, that „12% of trash is plastic“. Therefore, he sees the solution in using compostable plastics also to complement our already compostable (but typically not yet composted) waste and reinforce composting as part of our waste management. In addition, most flexible plastics is discarded – and even if collected in a curbside recycling bin – will be soiled.

It is important to differentiate between compostable and biodegradable. Biodegradable is a general term for products that, over an undetermined span of time, will degrade on their own. Compostable on the other hand, means that under a controlled environment with specific heat, oxygen and moisture conditions will turn within six months into decomposed soil that can be used to enrich soil, an extra value-add derived from compostable flexible plastics. Certain standards define exactly compostability, such as Australian Standards AS 4736–2006 or AS 5810–2010, and/or European Standards EN 13432 for home or industrial composting. TIPAs products meet these international standard requirements.

To Kneefel, “Compostables have an important role to play (…). It is TIPA’s vision that through organic recycling we can help solve the plastic pollution crisis and revive our degraded soils. However, we recognize that this vision can only materialize when we collaborate with key stakeholders in waste management across the value chain, and demonstrate the socio-economic benefits of adopting this new system to policy makers.”

Other stakeholders involved and engaged with compostable flexible plastics are municipal waste management facilities.

In some municipalities, composting facilities are accepting compostable plastics bags and advocating for them. The advantages of using compostable plastic bags are: less plastic contamination in organic waste, but also an increase in organic waste separation and collection.

According to the Italian Compost and Biogas Association (CIC), Italy treated 4.6 million tons of wet food waste in 2020. Biowaste recycling in Italy is 42% of all material recycling and has been seperately collecting food waste since 1990. Part of the success of biological waste collection and treatment, is that Italy introduced a law in 2010 for food waste to be collected either with reusable containers or with food waste collection bags certified to the EN13432 standard on compostability. In 2019, single use carrier, and fruit and vegetable plastics bags were banned unless compostable, and the citizens were encouraged to reuse these as liners for organic waste collection bins. This has led to the very low contamination of compost by plastic at 1.5% , compared to 5% or more in other EU countries.

The example of Italy is showing not only that plastic litter is reduced with the use of EU certified compostable bags, but that organic waste separation and collection increases reducing the amount of residual waste.

On a practical level, these developments in Italy supports the claim by the PEW Charitable Foundation that 8% of plastic litter could be avoided by using compostable plastic bags – with lock-step composting infrasctructure in place.

The City of Vienna Waste Management Department MA48 operates the biggest composting facility in Europe since 1993, which processes all the collected organic household waste and other yard waste. MA48 has published a position paper on compostable flexible plastics.

Dipl. Ing. Wojciech Rogalski, Responsible for Strategy and Planning of Waste and Material Flow Management of MA48, summarizes, „The use of fully biodegradable plastic bags as a collection aid for organic waste, specifically if this is collected separately, shall be allowed, as per the position paper “Compostable Plastic Bags as a Collection Aid for Organic Waste”. However other so-called “bio plastic waste” that does not conform to EN 13432 must not be put into collection bins for bio waste .“

The use of biodegradable collection aids is expected to increase the acceptance of separate organic waste collection in Vienna, and has been proven in Italy. Greater acceptance usually leads to an increase in collection volumes and thus to a reduction in the biogenic content of residual waste, as has also been proven by the developments in Italy as explained above.

The Italian scenario and Austrian committment prove that, while still just a small and very niche portion of the market – EU certified only plastic carrier bags so far, and TIPA only sells products for applications in the dry food and fashion sector- compostable plastics prove to offer a promising and well defined part of the plastics litter solution that is also the cheapest, easiest and most value-add to implement in conjunction with existing municipal waste management infrastructure.

Even the Austrian Compost and Biogas Association (KBVÖ) welcomes the use of EN13432 certified compostable plastic bags to mitigate the problem with micro plastic litter. Both MA48 and KBVÖ seem to disagree with TIPA, however, on the value-add of the decomposed plastics on the soil/compost – they claim „composting plastic“ is a missed opportunity for gaining thermal energy from incineration of plastic.

Recyclable flexible plastics so far are do-able but more well intended than a practical reality any time soon, mostly because the collection, seperation, as well as a most cost effective and truly circular mechanical or chemical recycling is not yet in place. Compostable flexible plastics provide more realistic circularity, provided the composting infrastructure is available, with the added benefit that organic waste becomes increasingly separated from residual waste when compostable plastic bags are provided.

And if composting is too dirty, there is the promise of the newest innovation in single-use plastic recycling, that of upscaling PET bottles: it was recently published, that a team at the University of Edinburgh genetically engineered E. coli to allow it to convert terephthalic acid – a molecule derived from polyethylene terephthalate (PET) – into vanillin.