We’re surrounded by the most valuable engineering material of the century, and yet it has such a low ‘value’ some countries do not even collect it after the first use. This is the modern scourge; China likes to point this out as an ‘issue of the West’ when in reality the consumption of polymers is racing away all over the globe. Take a visit to the supermarket… Count how many metres you can walk before seeing or touching something made from plastic. Then consider, in a weekly shop, how many items are wrapped in ‘cheap’ plastic film or are in plastic containers. Then try and eliminate plastic. This is even harder than eliminating added sugar from our diet. For vehicles, components are frequently wrapped in plastic, and made from plastic too.
What becomes of ‘plastic’? Most of it goes into holes in the ground (Europe) or gets sent to an unsuspecting nation who then find the containers which were offered around the world to be shipped to the Far East for almost nothing, are full of plastic waste. Unsurprisingly, many countries who used to receive such waste have stopped imports, but still the mountain of debris builds up day-by-day.
Sea-life, plastic straws and reality
The major issue is ‘plastic’ is covered in a huge array of polymers, which broadly fall into four categories:
• Thermo plastics – these will melt given enough heat.
• Thermoset plastics – the polymer cross links during the manufacturing curing process, which means the only way to undo this is to grind up the material and use it as a filler for other applications.
Fibre-reinforced thermo plastics – frequently used for automotive structural parts such as boot lids, tail gates and front panels. Because of the fibre content, which is usually short chopped glass fibre, it is not economically viable to extract the polymer. So, the usual recycling process is the same as for thermoplastics.
Fibre reinforced thermoset plastics – not so common now, but have been used in the past for selected skin panels and reinforcements. Again, the only effective recycling is to grind it up and use as a filler for other applications. When the fibre has a higher value, especially as a woven fabric such as Kevlar or carbon fibre, there is a drive to recycle – but effectively until the first thermo plastic reinforced with carbon fibre appeared in 2018, this was all but impossible. There is a complication, though. Where a single polymer is used, then there is a possibility to extract thermoplastics for recycling. Usually customers of the recycled material demand the polymer is identical and of the same colour – which means most possible recycling is rejected. The plastics industry, however, likes to make endless special formulations, and components made from multiple polymers – which often effectively become un-recyclable. A good example of this is heat resistant disposable cups. There are two layers of papers, a way based or polymer coating on the inner face and a polymer between the two layers of paper. The result? Yes – you guessed – it makes no economic sense to separate the components. So, we turn to the Social Media celebrity, the plastic straw. Made famous by Dear Sir David Attenborough during one of his many programmes about wildlife and the impact of humans, it became very political. How simple! Ban the plastic straws! However, the paper- based replacements are… unrecyclable. Land fill, here we come.
Messing about with plastic straws is typical political fodder – high profile, almost no impact and does not address a primary source of marine pollution. It would seem plastics in the ocean come from at least two sources: Waste dumped at sea, and commercial fishing.
‘Burn Baby Burn’ (MoTown, 1976)
What’s is the best solution? Well, unless we can be sure the component isn’t possible to save (3D printing, anyone), that it is made from an identifiable single polymer, that it is not reinforced, and joins a pile of waste made from the same materials, we should burn it. Take a look at the Audi A3 MQB Evo headlight assembly, and see how many parts are made from ‘plastic’. Nearly the whole assembly is made from various polymers, each selected for the best performance in its first life with nominal thought for the life afterwards.
Of course, releasing the oil-derived energy cannot be done on an open fire or even a commercial furnace. There are costs to clean the flue gas, so removing most of the toxic elements. But otherwise, this is the most practical way to yield a positive use for what is regarded today as a cheap material.
This approach gets around the continuous drive for first use formulations which then effectively make recycling on an economically viable scale for second use almost impossible. Where such recycling does occur it is at source from a manufacturing plant, where defective parts are removed in bulk, where the formulation is identical and the second life user can process the otherwise scrap material.
That does not apply to a body shop. Sure, we have enough plastic film to wrap the building and throw away tiny clips by the hundred each month. To channel this into a robust recycling system is very difficult – and not really viable. What could be better than to persuade the company taking away the waste to invest in a special incinerator, where the heat from the burn is used to generate power? Perhaps I’m dreaming.
Tellingly, here in the UK where, like most of Europe, we think we are ‘green’ because the waste is collected but we have no idea where it goes, the process I’ve outlined already is not underway. There are a few waste disposal companies that have bought special incinerators for plastics, knowing that commercial customers already pay quite high fees to take waste away and the tax to bury it in the ground is rising.
However, there is no energy strategy, no policy on energy nor political will to speed this development up to encompass the 0.1 kg of plastic waste every single UK inhabitant throws away every week.
That’s around 6 700 tonnes of low-grade plastic waste per week (348 400 tonnes per year) mainly from food wrappings, from one country of 67 million people.
In the short term for South Africa, there is a source of energy which is difficult to collect – but is otherwise free. There is a cost to process it, and little point to just burn it without some sort of payback. So, that means local generation of electricity from plastic waste. This would require investment, but it is right up the UN’s agenda and so should attract international funding. In another century, people will not believe what we did with plastic. By then, as with gold mining spoil, technology and increased price which makes what is deemed today to be unviable, profitable. This could be the time to buy up otherwise worthless land fill sites in Europe and North America, with a view to mine them in a few decades for the energy trapped inside.
By then, of course, the polymer industry will either have reverted to a smaller number of polymers or come up with clever ways to extract them from products. Indeed, our whole approach will be different, where broken parts find their way into a second life rather than into the land or sea. Finally, ‘plastic’ will become valued as it should be – the most amazing, flexible and durable material known to mankind.
Auto Industry Consulting is an independent provider of technical information to the global collision repair industry via EziMethods, our online collision repair methods system. For more information please visit the website: www. ezimethods.com