Additive manufacturing – sustainable by nature
As an emerging manufacturing process, additive manufacturing not only has the potential to change the landscape for product development, manufacturing and logistics, it can also improve sustainability across a variety of industries.
In the long term, additive manufacturing might play a significant role in reaching the United Nation’s Sustainable Development Goals (SDG), according to Eduard Hryha, researcher and project manager for the new Centre for Additive Manufacture – Metal (CAM2) at Chalmer’s University of Technology in Sweden.
“To reach the climate goals, we must make significant changes to the way we manufacture products. Additive manufacturing is one of those revolutionary methods.”
There are two fundamental aspects that define sustainable manufacturing: the actual manufacturing process and the impact of the product produced. Additive manufacturing has significant effects on both levels.
Reduction of production steps
When it comes to the manufacturing process, some of the sustainability advantages are obvious. In the Powder Metallurgy – Intrinsically Sustainable report, the Metal Powder Industries Federation compares the 17 manufacturing steps that are required to produce a truck gear using subtractive machining with the mere 6 that are required using a powder metal process – with each less step bringing a saving in energy consumption.
Another major advantage is that the actual production can be undertaken locally; all you need to transport is powder. The printer can be placed at the customer site or very close by. This means that the number of transportations are reduced even more. Furthermore, additive manufacturing cuts down on material waste.
“When printing a component, approximately 95 percent of the powder you put into the process is used; the rest can be recycled in a new melt,” says Mikael Schuisky, Operation Manager, Additive Manufacturing, at Sandvik. “Compare that to traditional manufacturing where you start off with a chunk of material and reduce large amounts of chips.”
Higher resource efficiency
Even though the chips are collected and sent for recycling, the carbon footprint is substantially higher, due to heavier transportation and a much larger amount of material to recycle. This has a significant energy impact. Anna Douglas, Global Environmental Coordinator at Sandvik, explains that melting steel in the efficient scrapbased electric Sandvik steel mill requires approximately 500 kWh per ton. This is significant when compared to the resource efficiency of powder technologies.
Additive manufacturing is presently used mostly for producing components with complex designs or those benefitting from being light in weight. Weight reduction is a constant key issue for the aerospace industry, driven both by fuel cost and carbon footprint. The same is true for cars and trucks, and everything else that moves. Schuisky says that each kilogram of weight loss on an airplane saves 3,000 US dollars per year in fuel.
Despite all sustainability advantages offered by additive manufacturing, it is still a new technology that complements traditional, subtractive manufacturing. “Additive manufacturing is fantastic for certain applications, but for others subtractive manufacturing remains more productive,” says Kristian Egeberg, Head of Product Area Additive Manufacturing at Sandvik. “We have in-house competence to offer both, which is unique and also means that we can give our customers unbiased recommendations in terms of optimal production method”.