3D printing is no longer a monolithic entity: it consists of many different technologies and materials, and a wide range of printers. So the costs of printing, depending on how one defines them, also range very widely, and generalizations don't really apply. The point of this particular study is that, at the low end with a cheap printer, consumers can save money making actual end-production objects. Regarding what will or won't happen with the higher end of 3D printing, including the proportion of end-products vs prototypes, a recent study by the long-term market research firm in this area (Wohler Associates) shows that finished goods have grown from 3.9% to 28.3% of revenue in just eight years (2003 to 2012) across all 3D printing sectors. This is true for GE Aviation and other high-end manufacturers. Stay tuned.
3D printing may be cheap in the long run but the costs of the same in the short term are prohibitively high. Very few companies can afford to use any 3D printers, let alone afford to buy the same. The costs go way beyond the costs of buying regular plastic raw materials and, as such, most companies will most likely stick to the latter for a long while to come.
Greg, the health effects of the plastics used in 3D printing is definitely a subject that's received some attention recently. But the measurements of "green" are quite specific and don't take health effects on human users into consideration: they're usually aimed specifically at reducing energy use, and therefore carbon emissions in the environment. That requires using an entirely different set of variables and measurements from those used to measure health effects. I think it would be confusing to merge the two. OTOH, I do agree that the health effects of the materials need more attention.
Jim_E, I was skeptical, too about the $2,000 figure. But it's amazing a) how much plastic the average American household consumes in a year and b) how many things can now be printed at home using 3D printers because of the machines and the availabilty of online open-source .STL files, plus cheap materials. The earlier open-access article we give a link to details how the researchers arrived at that figure as the maximum.
Good perspective on the energy savings benefits of 3D printing. However, one further consideration to evaluate when classifying a 3D printer as 'green' is which process is being used? I may have a different definition than others, but I assume that 'green' also means less harmful or toxic to human beings.
Some 3D printers may use less energy, but certain processes use hazardous or toxic materials (which can be harmful to humans). One 3D process that I used would cause skin allergies if the user was over-exposed due to frequent contact. Another process caused my co-worker to have a brief case of silicosis. I would suggest that in addition to energy consumption, that 'green' metrics also include the potential impact to the environment and to the operator's health.
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