The economic advantages of metal additive manufacturing as an alternative to traditional methods are clear, but the reduced environmental impact may be even more important to the future of industry.
Shipping: An Enormous Carbon Footprint
The flow of raw materials into a manufacturing facility and finished goods out of it require enormous energy inputs allocated to shipping. Given that traditional manufacturing has been heavily reliant on fossil fuels since the Industrial Revolution, this process exacts a major toll on the environment. Together, the transportation sector accounts for over 30 percent of all U.S. emissions. Industrial transportation related to shipping undoubtedly comprises a major segment of this total.Complex, disjointed supply chains result in an end-use product that requires inputs to be shipped from hundreds of suppliers. Further, the completed product goes through multiple layers of distribution before it arrives in its buyer’s hands. 3D printing can’t fix all these problems, but it does have the potential to dramatically cut the number of links in the chain by allowing local, on-demand manufacturing of a huge variety of components. Without a doubt, 3D printing will eliminate millions of component shipping journeys in the coming decade.
Traditional Processes Waste Vital Resources
The largest segment of the metal parts fabrication industry is “subtractive” processes like CNC milling, in which material is cut away from a block to produce a final part.This brings us back to the key word, “subtractive.” The problem with this type of manufacturing is that any of the original block of metal that is cut away is waste. That wasted material represents additional resources that must be extracted from the Earth via potentially harmful mining practices.
Even worse, the final outcome for the scrap material itself involves one of two things:
- Additional shipping and processing to take advantage of whatever economic value the cast-off still has
- A trip to the local landfill, where industrial overcrowding is already a significant issue
Metal 3D printing, when economically viable, provides a nearly perfect solution to this problem. Because it’s an additive process, whereby material is layered onto itself in an exact pattern, there is virtually no waste associated. Only the metal that actually comprises the final component is used. The unused material can be recycled.This could mean the difference between 95% waste with CNC machining and < 1% waste using metal AM.
Toxic Byproducts are Common in Metal Manufacturing
Certain types of metal manufacturing, most notably CNC machining and metal injection molding, require the use of toxic substances as part of their process. The oils and lubricants needed to ensure CNC machines run properly are often dangerous to the environment. The finishing process for these parts can also make use of fluids that can be damaging if handled incorrectly. These must be handled carefully and disposed of properly.Needless to say, “properly” isn’t a standard to which all manufacturers worldwide are held. Some percentage of the harmful agents used in both CNC machining and metal injection molding will make it into the air, water, or soil that supports the community around a plant. It’s hard to quantify this, but the environmental impact is real.Standards for proper disposal of hazardous chemicals associated with conventional metal manufacturing can vary dramatically by world region.
Metal AM eliminates this concern entirely. The process simply doesn’t generate any toxic byproducts, which guarantees that air and water quality won’t be directly harmed.Conventionally made components can leave a much bigger carbon footprint than 3D printed parts.A less obvious environmental cost of traditional manufacturing lies in the efficiency of end-use products. Recent successes in metal 3D printing have changed what’s possible for fuel efficiency in a variety of places. The technology has enabled huge design improvements that shave off weight without compromising strength.
Lessening the Carbon Footprint Through AM-Enabled Design
3D printing allows for the manufacture of parts with complex internal geometries, often in ways that are impossible for conventional techniques to match. The upshot is that design changes that combine multiple parts into a single component can often be completed without sacrificing functionality–or feasibility. This accomplishes the goal of lowering cost and lead times by simplifying the manufacturing process, but it also comes with significant environmental advantages.
Additive Manufacturing Optimizes Designs & Efficiency
As the world marches toward an increasingly tenuous climate future, the costs of a suboptimal part made through traditional manufacturing must be considered right alongside the more tangible impacts described above. There are countless heavy or less-than-aerodynamic components in applications across every sector that could be improved significantly with the design freedom afforded by metal AM. In aggregate, the emissions reductions that are now feasible through projects like GE’s Advanced Turboprop engine would represent major improvement for humanity’s overall carbon footprint. Metal 3D printing doesn’t yet offer all the answers, but in a growing percentage of manufacturing situations, it’s a step in the right direction for our planet.
3DEO. (n.d.). Environmental Impact of Additive Manufacturing. Retrieved from https://news.3deo.co/environmental-impact-of-additive-manufacturing
- How is 3D printing reducing the carbon footprint?
- How is 3D printing reducing wastage?
- How is 3D printing optimizing designs and increasing efficiency?