HEAD 2 HEAD
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. What do YOU think? Join in the conversation in the Cafe Area.
AGREE ABOUT THE AUTHOR Jonathan S. Krones is a PhD candidate in the MIT Engineering Systems Division and 2014-2015 SchmidtMacArthur 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.
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3D printing offers a waste-free future. T
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he 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]
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.
a) Software model of the print showing support material in purple surrounding the print material in red.
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 1/3