The New Materials

8 minute read

The eleventh article of Earth Matters looks at how innovative materials and technology can help us manage our problem with plastic, one of the most pressing environmental challenges of our generation. Pioneering scientists, researchers, engineers and inventors are mapping an alternative, better future. One where plastic can be managed more sustainably by developing and discovering novel ways of overcoming the challenges of recycling it. And one where we can even take plastic out of the equation by inventing new materials that offer its same benefits but with less harm, and by reimagining traditional forgotten materials that have been usurped by plastic over the last century.

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Our problem with plastic pollution has grown to staggering global proportions, a scale that is so large that it is almost incomprehensible. A whopping 91% of all plastic ever made has become waste.[1] And this is hardly slowing down: the rapidly growing production of throw-away plastic products continues to outstrip our capacity to deal with them.

It is neither a coincidence nor an oversight that this topic and these statistics have been covered again and again in Earth Matters. Plastic presents a massive challenge for sustainability. Indeed, the problem has become so pervasive that there is now talk of a new United Nations global treaty to tackle the plastic pollution crisis.[2]

As it stands, plastic has a trusted, convenient and deeply entrenched place in every one’s life. It plays a part across the entire spectrum of how we produce, consume and dispose of products. And – in all but its eco-credentials – it is a “good” packaging material: it is lightweight, durable, inexpensive and offers excellent protection, increasing the lifespan of perishable goods (thereby actually helping to reduce waste in some way).

So that is the challenge. To find better ways of controlling and overcoming the plastic waste crisis that we are already in. And, in parallel, to support pioneering scientists, researchers, engineers, inventors and brands to find viable alternatives to plastic. In this way, we can hope to forge a future where we go cold turkey on plastic forever.

For some materials, recycling is an effective solution. For example, aluminium and glass are infinitely and relatively easily recyclable. But for plastic it’s a different and more challenging story, globally. Plastic pollution is most problematic in developing Asian and African nations, where waste collection is often ineffective or non-existent.[3] But the developed world (especially countries with lower recycling rates) also has challenges when it comes to effectively collecting and processing redundant plastics.[4]

The first challenge is that there are so many different types of plastic, all with different properties. This makes plastics difficult to sort and process correctly. Recyclable and non-recyclable plastics often end up in the same processing stream, which means they have to be re-sorted. Not all collectors do this, and it vastly impacts the resale value and recyclability of the material.

There are high tech processing plants that can effectively sort plastics, but these come with their own challenges and are not universally available. The three main sorting methods are:

• • • Near Infrared Spectroscopy (NIR): An infrared sensor distinguishes materials based on how they reflect light, and an air jet is used to blow materials into separate streams. Dark plastics can be problematic for NIR.
    • X-Ray Technology: X-rays are used to sort different types of polymers according to their density.
    • Sink-Float Density Separation: A specialist floatation bath is used to separate plastics based on their density. Different types of plastic float at different levels, allowing them to be effectively sorted.

The second challenge with recycling plastic is its colour. Plastics are produced in hundreds of different colours which, when recycled together, mix to become an unattractive black or brown hue, greatly reducing their usability in consumer-facing applications. Technology is being trialled in Germany[5] where a series of miniature robotic cameras sort shredded plastic pieces into colour groups with the hope that specific hues of plastic can be returned to the supplier or brand (e.g. Coca-Cola red or Cadbury purple). However, this technology is still in development and not widely available.

The third challenge is that it is very difficult to bring recycled plastic back to virgin material quality levels. Different additives are used in plastics depending on their intended use. This means that, even if plastics are correctly sorted by type, additives can react in different ways during the recycling process, which can result in issues like clear or white plastics turning an unattractive yellow once recycled.

The final challenge is that most consumers believe that simply putting their plastic in the recycling each week is helping the environment. But the ways in which recycling is collected and processed vary greatly at national and even local level. For example, different councils in the UK collect and process different types of plastic, which leads to confusion, contamination and varying recycling rates.

There is therefore both a need and an opportunity to create better solutions for recycling and reusing plastics. Considerable R&D investments have already been made, leading to a number of breakthroughs in recycling innovation.

Improving our waste management capabilities is essential to fixing the system. But it is not enough. New alternatives to traditional plastics are needed to wean humanity off its plastic addiction.

“Single-use plastics are a problem. There are a variety of ways to address the issue. Waste management is one, but not the only one. We need to look at alternatives and reduce the use by 2030. That’s the global message.”

– Hugo-Maria Schally, DG Environment, European Commission

Traditional plastics are made from petroleum-based raw materials. Bioplastics are plastics made from 20 percent or more renewable materials such as corn starch, wood or even food waste.

There are several advantages to bioplastics over traditional oil-based plastics, including reduced use of fossil fuels, a smaller carbon footprint, and faster decomposition. They are also less toxic than traditional plastics and do not contain the hormone disruptor bisphenol A (BPA).[6] Given these advantages, it’s easy to see why a number of industry marketeers are touting bioplastics as the panacea to our plastic pollution problem. However, the argument for bioplastics isn’t that clear cut.

One of the most common types of bioplastics in use is PLA. PLA is a thermoplastic typically made from the starch in corn, cassava, sugar beet pulp or sugarcane. PLA can look and behave like polyethylene, polystyrene or polypropylene. However, when it comes to overall strength PLA can’t compete with traditional plastics [7] and its cost is also substantially higher.

Disposal of bioplastics is also not as straightforward as one might hope. If bioplastics inadvertently end up in landfill (and many do) and without enough oxygen, they won’t break down and can last for centuries. In other words, the dangers posed to Mother Nature when bio-plastics are disposed of improperly and end up in the environment are similar to petroleum based plastic.[8]

Furthermore, consumers often cannot tell the difference between bioplastics and traditional plastics, meaning there is a high chance of them being disposed of incorrectly, becoming mixed with plastics such as PET and contaminating recycling streams. The industrial composting facilities required to break down many bioplastics also vary greatly depending on locality, and in some areas this infrastructure simply doesn’t exist.

Because PLA is made from plants, this also exacerbates the environmental problems that large-scale agriculture can cause. The sugars used to make bioplastics often come from crops treated with herbicides and pesticides, and these crops use land that is much needed to grow food for the growing global population.

An alternative bioplastic that negates the need for farming land is PHA. PHA can be made from sugars grown in algae, so there is no impact on food production. However, using algae to produce bioplastic ingredients is currently expensive and there are several more years of development needed before PHA plastics can be scaled up to a level that decreases their cost and makes them a real contender against PLA and traditional plastics.

The plant-based solution is complex and still very much in flux. But the right partnerships between innovators and brands can help boost these material alternatives to the level required to make them scalable, viable and global.

Plastics have been part of our lives for a long time – 1907, to be precise, which is when Bakelite was created. And although innovation and new materials can and must play a huge role in replacing traditional plastics, there is also much to be learned from looking backwards in order to move forwards.

Brands are looking to materials used before the world fell in love with plastic and finding sustainable solutions in traditional materials. These old resources that have fallen out of fashion are being innovatively rethought and redesigned to create materials and products that have great performance and are also better for the planet.

Our passion for plastic is deep and complicated. And it isn’t going away anytime soon. In fact, as outlined in Single Use Backlash, the ongoing pandemic is both intensifying the problem and thwarting positive changes in consumer behaviour and government legislation.

However, we can’t continue to make, use and discard items from a material that will be polluting our planet for potentially thousands of years after we have gone. There is another way, a set of viable solutions waiting to be uncovered in the future, and rediscovered in our past.