How 3D Printers Work
"First invented in the 1980s by Chuck Hull, an engineer and physicist, 3D printing technology has come a long way. Also called additive manufacturing, 3D printing is the process of making an object by depositing material, one tiny layer at a time.
The basic idea behind additive manufacturing can be found in rock formations deep underground (dripping water deposits thin layers of minerals to form stalactites and stalagmites), but a more modern example is a common desktop printer. Just like an inkjet printer adds individual dots of ink to form an image, a 3D printer only adds material where it is needed based on a digital file.
In comparison, many conventional manufacturing processes -- which have recently been termed “subtractive manufacturing” -- require cutting away excess materials to make the desired part. The result: Subtractive manufacturing can waste up to 30 pounds of material for every 1 pound of useful material in some parts, according to a finding from the Energy Department’s Oak Ridge National Lab.
With some 3D printing processes, about 98 percent of the raw material is used in the finished part. Not to mention, 3D printing enables manufacturers to create new shapes and lighter parts that use less raw material and require fewer manufacturing steps. In turn, that can translate into lower energy use for 3D printing -- up to 50 percent less energy for certain processes compared to conventional manufacturing processes.
Though the possibilities for additive manufacturing are endless, today 3D printing is mostly used to build small, relatively costly components using plastics and metal powders. Yet, as the price of desktop 3D printers continues to drop, some innovators are experimenting with different materials like chocolate and other food items, wax, ceramics and biomaterial similar to human cells."
Read more: http://energy.gov/articles/how-3d-printers-work+U.S. Department of Energy