The process of creating three-dimensional objects from a digital file was once limited to making prototypes or small, aesthetic models. But recent advances mean that additive manufacturing and 3-D printing are being used to produce an ever greater variety of components and end products. CB Insights lists a full 25 industries 3-D print could “disrupt,” and research firm MarketsandMarkets predicts that the 3-D printing industry will grow to $32.78 billion by 2023.
Amid these developments, a discussion has taken shape around the technology’s impact on the planet, with proponents touting it as a major tool in fighting climate change. Still, confidence in 3-D printing’s environmental benefits is far from universal.
As the term suggests, additive manufacturing works by adding layers of material one by one until an object is complete. In contrast, subtractive manufacturing whittles down a solid block of material, such as metal or resin, to the right size and dimensions—in the process producing scrap that must be disposed of or recycled.
One 2017 paper found that creating objects layer by layer can reduce the need for and cost of materials by up to 90% compared to traditional processes. And although improved efficiency has brought the global industrial level of scrap waste down to 21% of materials used, PricewaterhouseCoopers (PwC) predicts that additive manufacturing could lower that rate even further. That said, PwC notes that lowering this figure by 3 percentage points would require using 3-D technology to build 20% of finished products, a significant leap from the current 0.01%. Additionally, a study by the Organisation for Economic Co-operation and Development (OECD) points out that the shape of certain components can require extra support material, sometimes in excess of the printed object itself.
Others argue that since firms can use 3-D printers to manufacture products on demand, the technology could cut waste by eliminating overproduction. The durability of some 3-D–printed products and the ease of printing replacement parts could also extend product life cycles. But especially in consumer settings, some worry that the growing availability of 3-D printing could make printed objects seem more disposable. A paper in the Journal of Industrial Ecology cites “the possibility of dramatic increases in throw‐away products facilitated by endless customization.”
Objects and components made via additive manufacturing are prized for their lighter weight and superior geometry. The aircraft industry has been relatively quick to capitalize on these traits, using 3-D–manufactured parts to achieve greater fuel efficiency and lower emissions. GE claims that its Advanced Turboprop, a commercial engine consisting of 35% additive design, is 5% lighter and will burn 20% less fuel than competitors while delivering 10% more power.
While this same logic can apply to the fuel efficiencies of shipping lighter-weight products themselves, Dartmouth Tuck School of Business professor Richard D’Aveni believes that the biggest overall gains for the environment could be the reduced need for shipping altogether. Writing in Forbes, D’Aveni argues that “local supply chains” of “printer farms and mini-factories closer to customers” will cut into the demand for freight transportation, which he says accounts for a quarter of all carbon emissions in developed countries.
But the OECD calls this notion a “popular fallacy,” pointing out that at present only extremely simple products can be 3-D–printed in their entirety, meaning that parts and products have to be shipped to and from assembly factories. The 3-D printer feedstock material itself also still needs to be shipped, even when printing is done on-site.
3D Insider writes that though measuring the overall carbon footprint of 3-D printing requires weighing a variety of factors, the process was found by one study to use 50 to 100 times more electricity than more conventional injection molding processes. The OECD describes energy use as “by far the largest environmental impact of 3-D printing” and explains that “when printers do reduce total environmental impacts, they do so by combining low waste with low-impact material choice and low-energy processing.”
Propelling Green Solutions and Environmental Restoration
3-D printing may also find an application in improving green energy solutions. New Mexico–based science and technology firm Sandia National Laboratories claims that the complex designs enabled by additive manufacturing make its 3-D–printed solar panels 20% more effective at absorbing sunlight than conventional panels. US Air Force engineers and scientists continue to seek ways of making the production of 3-D–printed solar panels more cost-effective so that it can be adopted on a larger scale.
Others are using 3-D printing to help remove pollutants from water. One group of Italian researchers has developed a more affordable alternative to the activated carbon often used to absorb chemical compounds in waste water, removing pollutants in one test using a 3-D–printable porous hybrid material with 94% efficiency. Meanwhile, startup Nano Sun has created water-filtering membranes via 3-D printing that are reportedly five times as effective as traditional polymer or ceramic filters.
Another popular example of where 3-D printing has been used to benefit the environment directly is in restoring coral reefs that house marine creatures and protect coastlines from storms. Australia-based Reef Design Lab has been pioneering the technology for coral restoration, eco-engineering of seawalls, and wave break structures for erosion control. Digital 3-D printing is especially well-suited to mimicking the intricate structures created by nature in objects, including coral. But even as 3-D–printed coral reefs succeed at supporting marine life, Newcastle University researchers say their benefit can’t adequately compete against the damage of unchecked “climate change, pollution, and destructive fishing practices.”
Ultimately, quantifying the overall environmental impact of additive manufacturing and 3-D printing is challenging—doing so requires evaluating a number of countervailing factors and a growing body of research. “[A]n important implication of the complexity of assessing the environmental dimensions of 3-D printing is that its adoption and diffusion won’t automatically generate net environmental benefits,” wrote Journal of Industrial Ecology editor-in-chief Reid Lifset in the publication’s special edition on the topic. “Like other technologies, environmental considerations need to be integrated into the design and deployment of 3-D printing if it is to realize its full contribution to sustainability.”