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Dr Phil Reeves unpacks the sustainability credentials of the diverse and ever evolving 3D printing industry.
Not a day goes by without some coverage of 3D printing (3DP) on the web or in the press. We are led to believe that we are on the cusp of a third industrial revolution for the digital age, one that will turn classical supply chain and retail models upside down, with design data downloaded from the internet driving resource efficient home manufacturing. Yet it is worth remembering that the agricultural and industrial revolutions actually took decades. The 3D printing ‘evolution’ will be no different.
Less than 100,000 3D Printers are actually in use today. Even with an estimated current growth rate of 180% year-on-year, it could take as long as a decade for this technology to become truly pervasive in society.
However, irrespective of the current penetration of 3D printing within the consumer market, we should not decry the potential that 3D printing presents to society, the economy and the environment through wide-scale industrial adoption. Companies are already embracing Additive Manufacturing (AM) as an economically viable way of bringing low volumes of geometrically complex products to market, from hearing aids and dental aligners to iPhone cases and lamp shades. In many cases these products are made using design data derived directly from the consumer or patient, resulting in truly personalised products.
This reorientation of the supply chain has a number of environmental benefits. For example, products are made to order and not to stock, reducing redundancy and waste. There is also evidence that personalised products have a longer life in the hands of the consumer, though they do have less second-hand appeal.
In addition to reducing stock holding and over supply, AM/3DP also presents a number of resource efficiency gains during manufacture – particularly when used to make metallic parts. Traditionally, metal parts are either cast or ‘machined’ from a solid block of raw material, with a significant proportion of that raw material becoming waste. However with metallic AM/3DP, only the material required for part production is used, with a small amount of waste going into ‘support structure’ – a scaffold of material built around a part to hold it within the machine. Even allowing for support structure, metallic AM/3DP can use as little as 20% of the raw material used when machining a similar part.
Another of the benefits of AM/3DP is the ability to make complex lattices with near perfect strength to weight distribution, using the absolute minimum amount of raw material. If such light weight structures could then be used for transport applications, particularly in aerospace, they could reduce fuel consumption and CO2 emissions. Such applications are currently hypothetical rather than factual – but they will happen eventually.
Unfortunately, polymeric AM/3DP presents a less compelling environmental argument, as the processes are relatively inefficient in their use of electrical energy, and in some cases produce very high amounts of waste material, which cannot be reused and must be downcycled to other applications.
However, consumer recycling solutions for home 3D printing users are being developed. A number of emerging businesses also produce ethical feed stock material, sourced from waste dumps in urban centres such as Nairobi and Mumbai. But the home feed stock solution, though admirable, may have a detrimental environmental impact in the long term, as the efficiency of 1,000 home recycling facilities is unlikely to match the efficiency of a recycling facility supplying 1,000 consumers. Of course it could be argued that local material processing must be greener as it mitigates transportation, but research in this field has shown that material distribution contributes only a very small amount to the overall embodied energy of plastics, with resource efficient production having a far greater impact.
If ethical feed stock can be produced in the developing world using both recycled waste and clean energy, it could help to create a more sustainable material supply chain. However, at present there are problems matching the types of waste polymer found in the developing world with the polymers that can be extruded from consumer 3D Printers.
Once we are able to characterise recycled plastics for use with consumer 3D Printers, the opportunities for adopting the technology in the developing world could become significant. Mobile phone usage and internet connectivity are increasing almost exponentially in sub-Saharan Africa, South America and South East Asia. By coupling accessible, affordable and sustainable materials with low-cost 3D Printing hardware and access to a world of internet data, there is no reason why this technology could not be used to support healthcare, education, agriculture or disaster relief. It will just take time.
Dr Phil Reeves is the Managing Director of Econolyst Ltd, a global Additive Manufacturing & 3D Printing consultancy & research firm working across Europe, North America, the Middle East, Far East & Africa.
Photo credit: Kakissel/Flickr