Bury it

Materials World magazine
1 Mar 2018

With plastic packaging under attack for its environmental credentials, how can its design be improved for reuse and how viable are alternative wrapping materials? Ines Nastali investigates.

It is hard to get numbers and facts on packaging generation and its recycling in the UK. However, ‘The grocery sector accounts for about 70% of the packaging market and every year around 10 million tonnes of packaging is used in the UK,’ the industry association Waste and Resources Action Programme (WRAP) states.

While retailers that deal with over 50 tonnes of packaging materials over the course of a year are obligated to register as a producer and join a compliance scheme, their data, submitted via the National Packaging Waste Database (NPWD), is not publicly available. The only public data that the NPWD publishes is how much waste has been recycled or exported. 

For the first month of 2018, 28,354 tonnes of packaging plastic waste was accepted and exported, according to the NPWD. However, the split between the two is not given for the same time, so it is unclear how much waste the UK exported into other – and which – countries. 

At least the split is, however, stated for the third quarter of 2017. In total, 274,588 tonnes of plastic packaging waste was accepted or exported, with the majority of 180,576 tonnes being exported and the remaining 94,013 tonnes accepted for reprocessing. 

‘This represents an increase of 9% on previous levels and includes an additional 8,000t from domestic reprocessing and 13,000t from exports. Based on packaging obligation data and including carryover from December 2016, plastic packaging has met 82% of its 2017 target,’ WRAP states in its Market Snapshot January 2018, adding that ‘total monthly plastic exports have been broadly unchanged between September 2017 and November 2017 at close to 50,000 tonnes per month’. 

The diversion of exports of plastics, due to China not accepting plastic packaging for import, has kept overall UK exports stable nevertheless, WRAP states. ‘Exports to Malaysia rose to 16,000t in November (from 3,000t in January) while exports to Vietnam increased from 6,000t to 9,000t over the same period. Exports of plastic to China/Hong Kong totalled just 4,000t in November, just 8% of overall exports in November and down from 37,000t at the start of 2017.’

Recycling conundrum

While consumers are increasing their recycling, and have done so in recent years (see Materials World January 2018), the problem is that ‘demand for recycled plastics today accounts for only around 6% of plastics demand in Europe,’ according to a EU Commissions report, A European Strategy for Plastics in a Circular Economy, which was published in January 2018.

‘In recent years, the EU plastic recycling sector has suffered from low commodity prices and uncertainties about market outlets. Investments in new plastic recycling capacity have been held back by the sector’s prospects of low profitability,’ it is further stated.

Plastics recycler Vanden Recycling, UK, therefore believes design improvements are needed. ‘Too much plastic packaging is difficult to recycle, for example vacuum packed meat trays with multi-layers of different plastic types. The cost to recycle these is more than the market will pay. This makes them unsustainable and so we should render them obsolete,’ David Wilson, Vanden’s managing director stated in a press release. He is convinced that ‘if packaging designers, retailers and manufacturers designed for ease of recycling, reprocessing costs would reduce, quality would improve, and demand would increase. This would make it an easier decision to invest in UK reprocessing infrastructure’.

The board members of the Institute’s Polymer Society confirm these challenges. Stuart Patrick, Interim Chair of the Board, said, ‘The main issue is, of course, single-use consumer areas, such as plastic straws or coffee cups, where there is no plan for reuse, litter collection and recycling schemes across the world. The idea of plastics-free aisles in supermarkets catches the mood but would you want a hospital ward without plastic catheters or tubing?’ 

Better bioplastic

Support for Patrick’s approach comes from Paul Mines, CEO of Biome Bioplastics, a developer of materials based on plants. ‘While waste within the convenience economy should certainly be tackled, it is neither realistic nor sustainable to work towards the total elimination of plastics for packaging and other convenience items. Plastics play a crucial role in preserving product both physically and from the effects of moisture, oxygen and other contaminants.

‘Further, we cannot over-rely on recycling when we consider dwindling market interest for low-grade materials, issues around food contamination and the problem of hybrid materials such as coffee cups,’ said Mines. But, if there is no hope in recycling, how else can the problem be tackled? ‘We must convert to materials based on natural, renewable resources and produce plastics that – after multiple use – are fully compostable, leaving minimal impact on the environment,’ he said, adding that ‘our industrial biotechnology development programme has already produced bio-based chemicals from lignin – the woody materials in plants and an abundant renewable carbon source – at industrial testing scale‘. 

He claims that these chemicals could revolutionise the bioplastics market, creating polymers that can compete with oil-based polymers on both cost and functionality. What sounds good in theory, does, again, not convince industry. WRAP states concern about the use of bioplastics. ‘The progress and rate of degradation is unknown, rendering the recycled polymer untrustworthy for any long term durable second life application,’ according to the organisation’s 2017 market report. 

Make it compostable

To go full circle, it is therefore necessary to design edible, water-soluble or compostable packaging materials, a report by the Ellen MacArthur Foundation, The new plastics economy, states (see Materials World November 2017 for more on giving soil nutrients back through degrading materials).

Meanwhile, Full Cycle Bioplastics wants to do what it says on the tin. Bacteria in organic waste produce their polyhydroxyalkanoate (PHA) based bioplastic, which is, the company claims, compostable, marine degradable and cost competitive with fossil-fuel based plastics. ‘Like most bioplastics, our PHA is not recyclable with other oil-based plastics, and should not be thrown in the traditional plastic recycling stream. Instead, our PHA is up-cyclable. ‘When thrown into the green waste stream, it can be taken to a Full Cycle facility, broken down and remade into virgin PHA,’ the company states, adding that ‘how fast it degrades depends on how many bacteria can get to it. In environments with large amounts of bacteria, such as compost rows, it can degrade in a month. In a clean and stable environment, like a store shelf, it can be kept for years’. Other start ups on the way to commercial use, include Ecovative’s mushroom-based polystyrene alternative, which computer company Dell already uses for its packaging. Then there is MonoSol’s wrapping for detergents and litter bags, which are water-soluble, or chitosan, an edible coating with antimicrobial features that slows decay of produce (see Materials World October 2017). However, a sustainable, mass-producable packaging that can replace plastic has not yet been manufactured.