Pandas may be cute, but they sure are stupid. 3D Printing often gets championed as a game changing technology, the salvation of everything, from bringing manufacturing back into high wage economies to stimulating innovation and making the next generation of Jonny Ives and Brunel wannabes. To my knowledge, no one has yet claimed that 3D Printing can be used to help the panda’s reproductive shortcomings. But it’s only a matter of time.
The polar bear on the other hand (or paw), should rightly advocate the benefits of 3D printing as a more sustainable way of making things – but not for the reasons you might imagine! If you can’t imagine why a polar bear would advocate for 3D printing, hang on a minute.
For almost a decade now there has been a deeply held belief by some that 3D printing could have significant and sustainable benefits to the environment. Surely it makes sense – 3D printing appears to be clean, lean, and green. It’s office friendly and it doesn’t operate in the dark satanic factories of yesteryear with the hell and brimstone, smoke and fire of past industrial revolutions (that’s poetic license for a foundry).
Perceptions can often be highly misleading
As standalone technologies, most 3D printing platforms are grossly inefficient when it comes to energy consumption and conservation. If we compare them to processes like injection moulding, casting and machining on a kilogram of material processed per hour basis, they are sadly lacking.
Take polymeric laser sintering or closed chamber FDM as two examples. We heat a significant body of raw material or air to an elevated temperature where we hold it, often for days, as we very gradually add or extrude, at best, a couple of hundred grams of raw material per hour. A woeful ratio of productivity to energy consumed when compared to other manufacturing approaches.
In the case of laser-based systems, these shortcomings are compounded further, as we use an inefficient energy source processed through an inefficient optical train. We are effectively turning 500w of source power into 200w of melting energy and 300w of wasted heat – which we then cool using an ancillary chilling system! Added to this, some processes use irreversible, non-recyclable thermosetting materials with high embodied energy and embedded carbon.
Not so green after all?
It’s at this point where you could imagine the polar bear reaching for the panda’s self-help books and fixating on the thickness of the ice pack.
However, unlike the panda, the polar bear is smart and sees the bigger picture – in this case, environmental “life cycle analysis” or LCA for short. The principles of LCA are to look at the bigger picture – the very big picture – from the open cast mine at the front end of the supply chain to the remanufacturing and repurposing of products at the end of their effective ‘first-working life’ (the circular economy) and everything in between.
It is only when we start to look in detail at 3D printing LCA that both the “actual” and “potential” environmental benefits of the technology become apparent. There are benefits achieved through a reduction in raw material consumption at the front end of the supply chain and waste mitigation during the production phase. There are benefits achieved through innovative and optimised part design that lead to products with improved operational efficiencies. Last, there are benefits accrued over the life cycle or usage phase of a product or component part as it impacts on the systems around it.
Let’s explain this jargon with an example
Many low volume metallic products are made by machining the desired geometry from a block of material which is often significantly greater in mass than the desired part. In aerospace we call this the buy-to-fly ratio, or the ratio of material purchased to material flown. Ratios of 10-to-1 or not at all uncommon, ratios of 100-to-1 are not unheard of. For desirable aerospace materials such as titanium and aluminium this presents companies with a number of challenges.
Firstly, there is the environmental impact of the bulk material needed and the waste produced, but also the economics and lead-times associated with sourcing ‘billets’ of material only to turn them into machining chips. Machining chips are often contaminated with cutting fluids that have to be expensively removed and then often only sold for down-cycling.
This is where making parts additively from powder feed stock could present a more sustainable alternative.
Even though raw materials have to be converted into powder from billet to enable many (metallic) additive manufacturing processes and waste streams are produced through support structures, the embedded energy of these “additional steps” is often mitigated by the overall reduction in the embodied energy of the raw material needed. In short, material efficiency in 3D printing offsets machine inefficiency for many material classes and processes.
Design optimisation
But with 3D printing we don’t just want to make a facsimile of the parts we would have made by machining, we want to improve on the design and optimise it using the design freedoms of the technology (see the GE bracket challenge). This redesign benefit then cascades both up and down the supply chain.
Through design optimisation, we use less raw material at the bottom of the supply chain to enable our products, and our products weigh less when they get to the top of the supply chain where they are used. Taking our aerospace example - part weight reduction manifests as weight savings in the aircraft, resulting in an increase in fuel efficiency. The airline and the passenger benefit economically, but the environment also benefits from decreased emissions.
But these benefits are not always easy to identify or to quantify. They change depending on the front end supply chain, the part use case, the life cycle, the vertical market application, the efficiencies of the 3D printing supply chain used, the location of the primary material production, the type of materials used and the location of the 3D printing factory employed.
In short, LCA is complex – but it supports and adds to the business benefits and drivers for the adoption of 3D printing, and that has to be a good thing. It also supports the realisation that environmental good practice is intrinsically linked to wealth creation – a view point widely championed by global through leaders such as Al Gore’s Investment firm - Generation
So back to our polar bear - luckily for him the country of Iceland has all the hallmarks of the perfect location for a 3D Printing eco-economy. Iceland has clean, green geothermal electrical energy, natural heating, and natural cooling. Maybe one day the polar bear can walk across the newly reformed transatlantic ice shelf to take a look at the Stratasys Direct Manufacturing facility in Reykjavik*, with extruders and platforms driven using clean, renewable energy and a geothermally heated build chamber heated geo-thermally. Unfortunately, I fear the panda will miss the party.
Note* - At this time, Stratasys Direct Manufacturing has no plans to open a facility in Reykjavik
