How sustainable is 3D printing?

3D Druck Prothese
Quelle: Bild von splotramienny auf Pixabay

What do house fronts, human hair and prostheses for injured turtles have in common? All of them can now be created using additive manufacturing or 3D printing. This technology means a huge upheaval with great opportunities – new business opportunities for innovative companies and opportunities for more sustainable production. It’s no longer just about the maker community, 3D printing has become an issue for business and industry.

HOW GREEN IS ADDITIVE MANUFACTURING?

Almost too good to be true: the new 3D printers can basically produce everything. From concept models to small series production to maintenance and repair of worn products: additive manufacturing redefines production.

In product development, there is a trend away from pure cost orientation towards resource efficiency and sustainability. At the same time, sustainability is considered to be cost-efficient; every use of material and energy ultimately costs money. This is another reason why additive manufacturing is currently on everyone’s lips. 3D printing opens up the possibility of efficiency throughout the entire product lifecycle, right through to repair.

As is so often the case with new technologies, however, not all that glitters is gold.

3D printing does not always make sense and it is not always more sustainable or ecological than conventional manufacturing processes, such as machining. The sustainability effects of additive manufacturing processes are currently largely unexplored (see Lachmayer R., Lippert R.B., Fahlbusch, T. (ed.) 2016: 3D-Druck beleuchtet; Springer Vieweg; Berlin).

One advantage of 3D printing, for example, is that components can be produced on demand instead of on stock. The result is lower storage costs or the avoidance of overproduction. The ecological effects also include the possibility of repairing wearing parts and the fact that 3D printing does not require any environmentally harmful coolants or lubricants, or that there is no tool wear because no tools in the conventional sense are used during production. However, the increased efficiency in the process chain, savings in material and energy during production and the lower weight of the component are also sustainable.

For example, 5 – 10 percent of the weight of a car can be saved by additive manufacturing processes. As a result, less fuel is needed. In aircraft, weight savings have an even greater impact. The weight of aircraft can be reduced by up to 7 percent and fuel consumption by up to 6 percent.

SUSTAINABILITY STRONGLY DEPENDENT ON MATERIAL AND PRODUCT LIFE CYCLE

3D Druck additive fertigung
Quelle: Bild von Michaił Nowa auf Pixabay

An example calculation with an aluminium component (see ibid.) showed that the raw material had to be used less for the additive process and that, in the end, less material had to be recycled. The raw material is therefore used much more efficiently. As a result, CO2 emissions are reduced right from the start. But there are also major disadvantages: production takes longer and the laser sintering system used is incredibly energy-intensive. In addition, some of the pulverized raw materials are very sensitive and difficult to transport. Pulverized aluminum, for example, is highly flammable.

According to the TAB report (Büro für Technikfolgen-Abschätzung beim Deutschen Bundestag, source: https://www.tab-beim-bundestag.de/de/pdf/publikationen/berichte/TAB-Arbeitsbericht-ab175.pdf) on “Additive manufacturing processes”, there are other potentially difficult aspects of sustainability. For example, parts that were previously made of wood could now be made of plastic – including a negative life cycle assessment. Even the recycling of additive parts, which are virtually “cast from the same mould”, can be more complicated in some cases.

Whether 3D printing is really more sustainable depends strongly on the material, the process and the technologies, the assumed flow of goods and the concrete products considered and their application contexts (see TAB report “Additive manufacturing processes”). Steel, for example, can be produced with much less CO2 than aluminium, so that the advantage of using less material would no longer be sufficient to justify the energy-intensive use of additive manufacturing.

But it is only a matter of time: If 3D printing machines become more efficient in the future (forecast is that 3D printers should be twice as fast in 2020 as in 2015), for example through better insulation or shortened production times, this can change. It is also important to consider the entire product life cycle. If you look again at the example of the lighter vehicle, it is possible that production may be very energy-intensive – but the car will consume less fuel in use over many years.

3D-PRINTING HAS GREAT POTENTIAL FOR THE MECHANICAL ENGINEERING LOCATION GERMANY

As is so often the case, the example of additive manufacturing once again shows that we have to take a close look at new technologies, because there are no simple answers here. In view of the exciting prospects for more sustainable manufacturing processes, it is therefore important in my view to conduct research in order to be able to calculate more precisely in which cases 3D printing really makes sense and on the other hand to research faster and less energy-intensive technologies.

One thing is clear: additive manufacturing offers unbelievable potential for Germany as a mechanical engineering location.

It is now up to us to exploit this potential. The fact is that Germany is currently in second place after the US market leader. We are in a good position. But disruptive technologies are constantly changing and other countries such as China and Korea are moving forward. In order to maintain our advantage as an early adopter, we need to go beyond the urgently needed research and strategically strengthen the market or support the shift from prototype technology to (small) series production.

The German government is already doing a lot. Beyond that, it is worthwhile to take a closer look at concrete projects and solutions of start-ups and SMEs and, if necessary, also to promote them. Apart from that, according to a study, the main barrier to a broader application and further development of additive manufacturing is the lack of specialist knowledge – this is where we on the political side must take a stronger stand than in the past.