HEAD 2 HEAD

The rapid development of additive manufacturing technologies, including both desktop- and factory-scale 3D printing, foreshadows an industrial future that might be vastly different from the present. Despite rhetoric to the contrary, properties of the printing process itself along with the broader effects of 3D printing on the manufacturing economy mean that this future will not be waste-free.

Current 3D printing processes, while avoiding the obvious material losses associated with milling, stamping, and other subtractive manufacturing techniques, are nonetheless waste-intensive. The main culprit behind 3D printing waste is the support structure: material that fills in negative space in the print to maintain structural integrity while complex geometries such as cavities, overhangs, or delicate features are formed (see Figure 1). At the completion of the print, support material is removed with techniques offering little possibility of material recovery, such as dissolution in a solvent bath. [1] In addition, research has shown that many 3D printers do waste significant amounts of their raw material: 40-45% in inkjet printing, [2] 20-45% in selective laser sintering of nylon, [3] and similarly substantial fractions from other powder-based methods. [4]

Ostensibly socially beneficial trends in manufacturing associated with 3D printing also forebode increased waste generation. Printers aimed at hobbyist and rapid-prototyping applications represent a decentralization of manufacturing capacity. Increased access to and distribution of this physical capital in turn enables more production to occur than would have otherwise, all of which ultimately ends up as waste. [5] Mass customization and on-demand production accompanying the 3D printing revolution are ushering in a new generation of planned obsolescence in product design, as last week’s products are discarded in favor of the color of the week. [6] The cheap, low-quality plastic used in many 3D prints exacerbates the wasteful trend away from product durability. Finally, additive manufacturing facilitates the hybridization of new material composites, which can have amazing properties but are major problems for recycling efforts. [7]

What can be done? Next generation printers might offer recovery of support material, improved yield

AGREE

ABOUT THE AUTHOR

Jonathan S. Krones is a PhD candidate in the MIT Engineering Systems Division and 2014-2015 Schmidt-MacArthur Fellow. His current research is focused on understanding amounts, types, sources, and destinations of non-hazardous industrial waste in the United States in order to assess the potential for reuse and recycling of that material.

“3D printing offers a waste-free future.”

For this ‘Head 2 Head’ series, we approached a number of people from a variety of backgrounds to write an opinion piece around a contentious statement, asking them to take either an ‘agree’ or ‘disagree’ stance. In some cases the authors have been deliberately provocative, and their goal is to contribute to a conversation around some chosen themes.

The views expressed here are the authors’ alone.

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a) Software model of the print showing support material in purple surrounding the print material in red.

Support material makes up a considerable fraction of the total print in this fused deposition modelling (FDM) 3D print done with a Stratasys Dimension SST 1200es with ABS filament and water-soluble support material.

DISRUPTIVE INNOVATION FESTIVAL 2014 ~ HEAD 2 HEAD

“3D printing offers a waste-free future”— AGREE

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rates, increased reliability, and advanced error correction, each of which would greatly improve the waste performance of the technology. The wastes from the economic impacts of the new manufacturing regime are more pernicious, with less straightforward remedies. Even if 3D printing leads to decreased waste elsewhere in the economy, the demand rebound from decreased manufacturing costs means that at best we would be breaking even. Achieving a waste-free future will require nothing less than a system-wide transformation, including strict material tracking and improved waste recovery and separation. In this way, the future offered by 3D printing is no more waste-free than our present is.

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References:

[1] Armbruster, M. (2012, July 18). 3D printing: understanding support material [Blog post]. Product Design & Development. Retrieved from http://www.pddnet.com/blogs/2012/07/3d-printing-understanding-support-material/

[2] Faludi, J. (2013, July 19). Is 3D printing an environmental win? [Blog post]. GreenBiz.com. Retrieved from http://www.greenbiz.com/blog/2013/07/19/3d-printing-environmental-win/

[3] Telenko, C., & Seepersad, C. C. (2010). Assessing Energy Requirements and Material Flows of Selective Laser Sintering of Nylon Parts. In Proceedings of the Solid Freeform Fabrication Symposium 2010: 8-10.

[4] Olson, R. (2013). 3-D printing: a boon or a bane? The Environmental Forum, 30(6): 34-38.

[5] Lomas, N. (2014, April 20). The 3D printing landfill of opportunity. TechCrunch. Retrieved from http://techcrunch.com/2014/04/20/plastic-problem/

[6] Heemsbergen, L. (2014, August 11). 3-D printers mean more plastic in landfills. The New York Times. Retrieved from http://www.nytimes.com/roomfordebate/2014/08/11/will-3-d-printers-change-the-world/3-d-printers-mean-more-plastic-in-landfills

[7] Olson (2013).

b) Completed print; support material in black encasing the white ABS.

c) Final product after support material has been dissolved away.

Images: Professor Caitlin Mueller, MIT

3D printing whilst no panacea holds specific opportunities for reduced waste juxtaposed against traditional manufacturing. 3D printing being additive rather than subtractive inherently reduces material waste. It’s design freedom allows sophisticated internal structures that provide strength, while reducing material requirements by as much as 90%. Experimentation at nano-scale using unique geometries for printed plastic materials has shown strength-to-weight ratios stronger than steel whilst less dense than water at 1000 kg/m^3. Further development of such materials, commercialisation and use within manufacturing would present weight reduction for products where weight is a factor, reducing energy and C02 implications of transportation. 3D printing has minimal tooling requirements and the potential for decentralised manufacturing enabling on-site on-demand manufacture, reducing wasted logistics, storage and embodied energy products. The ability to print bespoke items also offers scope for replacement components and repair. Thus increasing product lifetimes whilst minimising downtime and waste inherent in prematurely disposed products, something already happening within the aerospace industries.

Further to 3D printings characteristics innovation within materials will be paramount for it’s ability to contribute to a waste free future. Specifically the use of recycled or waste materials will be key. Current experimentation with recycled and bio-degradable materials like salt, wood, paper, soy and even citrus peel show what might be possible. This means that for certain 3D printing technologies will come the ability to print, shred, and reprint using the same material. Already demonstrated by Fused Deposition Modelling and Fused Filament Fabrication upcycling waste plastics into valuable 3D filament. Dutch architects push the idea further by building a canal house using a super sized printer. Their vision being to use and subsequently re-use recycled materials to print buildings on-site, with inherent waste minimisation. Protoprint take another approach, working directly with waste pickers in India to convert waste plastics into 3D filament, increasing earning potential and reducing wasted human and material capital. Further experimentation, innovation and research is needed across the full repertoire of 3D technologies and materials to assess the scale and possibilities. It can be argued that 3D printing also offers waste challenges, especially with the development of composite materials. However, if as part of 3D printings development recycled materials and recyclable composites are specified and preferred, 3D printing could become a key recycling technology and part of the recycling system itself.

Furthermore, as 3D printing is inherently open-source, many can do 3D printing, and therefore acts as a medium for education, experimentation and innovation. Likely the first time many interact with design, manufacturing and materials on a personal level allowing people to understand the whole process and system. Especially if in making things out of ‘waste’ subsequently the printed product is shredded and reused. This would highlight the need to minimise waste and ultimately the inherent value of materials. Educating, instilling and furthering perspectives of material science, experimentation, making and whole system process, thinking and design will hopefully show waste as an unnatural product of a poorly designed system. 3D printing could be the innovation to disseminate this perspective.

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ABOUT THE AUTHOR

Phil Brown has just finished his MSc in Environmental Management for Business at Cranfield University and is a Schmidt-MacArthur Circular Economy Fellow. His MSc and circular economy innovation project show the feasibility of using Waste Electronic and Electrical Equipment (WEEE) recycled plastics for 3D printing. Using a circular economy perspective to assess recycled materials and 3D printing opportunities, challenges and potential future impacts.

DISAGREE

DISRUPTIVE INNOVATION FESTIVAL 2014 ~ HEAD 2 HEAD

“3D printing offers a waste-free future”

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