rPET-industry – Plastics-sorting 27-05-2022
rPET-industry – Plastics-sorting
Many plastics that are labelled as biodegradable are only compostable under industrial conditions, but scientists at the University of Bath have now found a way to make plastics break down using only UV light.
As a result of increasing public concern over plastic waste, PLA (Poly(lactic acid)), created using lactic acid from the fermentation of sugars, is now widely used as a renewable, sustainable alternative to plastics derived from crude oil products — used in everything from disposable cups and teabags to 3D printing and packaging.
It is often labelled as biodegradable, however it has limited degradability in natural environments, for example in soil or in seawater, and it only degrades under industrial composting conditions of high temperatures and humidity — not achievable in domestic compost heaps. rPET-industry – Plastics-sorting
Now scientists at the Centre for Sustainable and Circular Technologies (CSCT) at the University of Bath have developed a way that could make these plastics more degradable in the natural environment.
The team found that they can tweak the degradability of the plastic by incorporating different amounts of sugar molecules into the polymer.
They found that incorporating as little as three per cent sugar polymer units into PLA led to 40% degradation within six hours of exposure to UV light.
Most promisingly, the technology is compatible with existing plastic manufacturing processes, meaning it could potentially be tested and adopted quickly by the plastics industry.
Publishing in Chemical Communications, the researchers hope their findings will be used in the future by the plastics industry to help make plastic waste more degradable at the end of the life of the product.
Dr Antoine Buchard, Royal Society University Research Fellow and Reader in Polymer Chemistry from the CSCT, led the research, which was supported by the Royal Society.
He said: “Lots of plastics are labelled as biodegradable, but unfortunately this is only true if you dispose of it in an industrial waste composter — if put into domestic compost heaps, it can last for years.
“Most PLA plastics are made up of long polymer chains which can be difficult for water and enzymes to break down. Our research adds sugars into the polymer chains, linking everything together by bonds that can be broken using UV light.
“This weakens the plastic, breaking it down into smaller polymer chains that are then more sensitive to hydrolysis. rPET-industry – Plastics-sorting
“This could make the plastic much more biodegradable in the natural environment, for example in in the ocean or in a garden compost heap.
“Previously scientists have looked at enhancing the degradability of PLA to water — hydrolysis — but this is the first time anyone has looked at using light.
Consumer giant Nestle’s recent announcement that it had reached 100pc recycled PET (rPET) content in all of Buxton water brand UK bottles is another sign of rampant competition for recycled content in packaging, and raises a question over whether supply can keep up with the growing demand.
Many companies and brands in the UK fast-moving consumer goods (FMGC) sector are aiming to increase recycled content in plastic packaging. Some, such as Buxton and Japanese firm Suntory’s blackcurrant drink Ribena, as well as all Coca-Cola Great Britain’s smaller bottles, have scaled up quite quickly to 100pc recycled content. But trade association the British Plastics Federation (BPF) estimates the current average level of recycled content in the UK PET bottle market is just 15-20pc, and space for others to scale up their use of recyclates is ever more limited.
The BPF’s Recycling Roadmap finds around 350,000t PET bottles were placed on the UK market, and environmental non-profit Recoup estimates around 75pc of these were collected for recycling. rPET-industry – Plastics-sorting
This is consistent with Argus estimates of an around 87.5pc operating rate of at the UK’s 300,000 t/yr of PET recycling capacity. The average ‘process loss’ during PET recycling in Europe is around 30pc, according to Plastics Recyclers Europe (PRE), meaning rPET output capacity is a little over 180,000 t/yr, or enough for a little over 50pc of bottles put onto the market.
The need for special certification for food-contact applications is a major bottleneck to supply, with just 30,000-35,000 t/yr of production capacity for food-grade rPET pellets in 2020 according to the BPF Recycling Roadmap, although this is likely to have risen.
The UK’s implementation of a £200/t ($250/t) tax on all plastic packaging with less than 30pc recycled content may add complications, because this applies to PET applications outside of the bottle industry, particularly trays. The UK PET tray market was nearly half the size of the bottle market in 2019, according to BPF data, but tray-to-tray recycling, which would create an rPET stream specifically aimed at non-bottle applications, has still to develop.
Scope for rPET imports is limited, given tightness in the European market and with the EU Directive on Single-Use Plastics (SUP) setting out an obligation for PET bottles to include 25pc recycled content by 2025. Meeting this probably means including more than 25pc rPET given the comparative difficulty of sourcing food-grade recycled polyolefins for caps and closures.
The more than 3mn t of PET bottles placed on the European market in 2020 suggests Europe-wide demand for food grade rPET would easily exceed 1mn t by that 2025 deadline. Latest data from PRE show just 632,000 t of rPET pellets manufactured in 2020. rPET-industry – Plastics-sorting
Nestle Waters UK head of corporate affairs and sustainability Hayley Lloyd House told Argus “there is higher demand than ever across many industries for recycled PET plastic, and the volume PET plastic collected for bottle recycling is not keeping up with that demand.” She said a Deposit Return Schemes (DRS) “is the best solution to increase bottle collection rates, whilst helping to improve the quality of recycled PET.”
Post-consumer recycled plastic is finally gaining the value it should have gotten long ago, due to its environmental friendliness compared to virgin material
Household appliances contain plastic components. Medical devices made of sterile plastic, such as disposable syringes and plasma bags, are indispensable to 21st-century healthcare. By preventing bruising and contamination, plastic packaging reduces food waste. Plastic cups and dishes are less fragile than ceramic tableware. PVC pipes and window frames have made house-building cheaper.
But not everyone who benefits from this wonder material knows that plastics production requires huge amounts of energy, most of which is generated by burning fossil fuels. Plastics plants are also a source of harmful pollutants including benzene.
Nor do all consumers appreciate the extent to which plastic waste is polluting the natural environment. Microplastics (fragments no larger than a fifth of an inch, 5.08mm) have been found in soil, in snow high above sea level and even in bottled drinking water. These pieces often break down even further, into particles known as nanoplastics, which are so small they can penetrate human organs and tissues.
Taiwan’s Environmental Protection Administration (EPA) is trying to wean the public off single-use plastics such as drinking straws and disposable cups. They’ve had some success, yet no one expects the daily torrent of discarded plastic to slow to a trickle anytime soon. rPET-industry – Plastics-sorting
Fortunately, other trends are converging to make humankind’s addiction to plastics less environmentally damaging.
The Future of Plastics Fund has made its first investment to support Greyparrot, the developer of an artificial intelligence waste recognition system and analytics platform intended to enable better sorting of plastics and other waste streams.
Greyparrot’s system is designed to automate waste composition analysis and the monitoring, auditing and sorting of waste flows at scale.
The investment, of undisclosed value, is intended to enable Greyparrot to expand into new waste streams. It has already analysed more than 10 billion packaging items in sorting plants.
Claire Shrewsbury, director of insights and innovation at WRAP, a sponsor of the fund, said: “There is an urgent need for investment which can support new infrastructure to increase plastic recycling. rPET-industry – Plastics-sorting
“Currently many of the technologies capable of addressing barriers in the plastic supply chains are still at a relatively early stage of development and need financial support to develop and come on stream.
“If we are to see an increase in recycling rates globally, and a reduction in plastic waste in the environment, then we need to support these innovative new technologies.”
Lucy Mortimer, a partner at the Future of Plastics Fund, said: “Much of the plastic that enters our economy never gets recycled. Problematic packaging formats and ineffective sorting means much can end up in landfill rather than finding value in the circular economy.
“Investment in Greyparrot will enable more material recovery facilities…to achieve a higher degree of sorting and a greater proportion of plastic being recycled.”
Greyparrot said it had also raised funds from a number of other sources totalling $11m in all (£8.8m) to enable it to later expand to new waste types.
It said there had until now been limited data on the 2.1 billion tonnes of waste produced each year and no systematic transparency on its composition or accountability for how it is managed.
“Despite consumers’ best efforts to recycle, poor packaging design and ineffective sorting means that much of what goes into recycling bins still ends up in landfill,” the company said.
Global motor manufacturer, WEG has successfully completed an energy saving project for Orleplast, a leading packaging manufacturer based in Brazil. With the initial goal of achieving greater productivity, Orleplast took the opportunity to invest in more efficient equipment for its site, turning to the experts at WEG’s Energy Efficiency Business Centre for support. rPET-industry – Plastics-sorting
Orleplast is one of the largest packaging and disposable plastic manufacturers and ias based in Santa Catarina, Brazil. Having established in 1992 specialising in manufacturing plastic hoses, Orleplast soon expanded and began to concentrate its production on a wider breadth of packaging supplies, such as bags, sacks and rolls. Today, the company produces about 600 tons of packaging products every single month.
When considering an upgrade to its equipment, Orleplast chose to prioritise efficiency to ensure better green credentials for its manufacturing site. Upon approaching WEG, Oreplast was specified a unique WEG technology, the modern line of W22 Magnet electric motors.
The W22 Magnet is a line of motors from WEG with permanent magnets in their construction. The inclusion of a magnet works to lower the temperature of the motor, enabling a reduction of its frame size in comparison to traditional induction motors. Another important feature is that the torque remains constant even at low speeds, so users won’t experience any decrease in productivity.
“One of the key benefits of the W22 magnet motors is that they operate at lower temperatures than traditional alternatives,” explained Marek Lukaszczyk, marketing manager for Europe and Middle East at WEG. “ As a result, maintenance costs tend to be lower because the bearings last longer in these lower operating temperatures.”
In addition to the use of W22 Magnet motors at 300 and 350 horsepower, the motor’s drive was replaced with the WEG CFW11 variable speed drive (VSD). Like all of WEG’s range of drives and inverters, the CFW11 can significantly improve the energy efficiency of a motor, thus improving the plant’s overall energy consumption.
According to an energy performance report, the savings from the new installation amounted to 286,416 kWh/year — that’s enough to supply 85 homes for one year. Orleplast also benefitted from a return on investment of just 2.7 years.
Such savings resulted in 36.2 tons of CO2 that are no longer emitted into the atmosphere annually. rPET-industry – Plastics-sorting
Commerce minister Wang Wentao recently expressed China’s commitment to achieving a comprehensive Asia-Pacific free trade area. He was speaking virtually at the 28th trade ministers’ meeting of the Asia-Pacific Economic Cooperation (APEC). He said all APEC members should take building an Asia-Pacific community with a shared future as the main line. rPET-industry – Plastics-sorting
The members should comprehensively promote practical cooperation in various fields of trade and investment, he said.
Free-trade arrangements should be explored as the main channel for promoting regional economic integration, and efforts should be made to advance regional inclusive development, he was quoted as saying by official Chinese media.
The minister reiterated that China will open its door wider and is continuously providing a driving force for the stable growth of global and regional economies.
The minister stressed that China firmly supports the multilateral trading system with the World Trade Organisation (WTO) as its core, maintains the security and stability of the global industrial and supply chains, and delivers more benefits to all parties.
APEC can play its role as a booster, stabiliser and incubator, and can provide strong support to the work of the WTO, he said.
rPET-industry – Plastics-sorting