Additive Manufacturing

Additive manufacturing builds a three-dimensional object by adding material layer by layer from a digital model, rather than removing material from a solid block as in conventional machining. Chuck Hull built the first working system in 1984, patenting stereolithography, a process that uses a laser to selectively cure a liquid photopolymer resin into a solid one thin layer at a time, and founded 3D Systems to commercialize it. As the underlying technologies diversified beyond stereolithography, into laser sintering, fused deposition and other processes, and moved from prototyping toward production of end-use parts, ASTM International's Committee F42, formed in 2009, adopted additive manufacturing as the standardized umbrella term for the whole field, distinguishing it from 3D printing, the popular but narrower term that, strictly, names only one process among several the standard classifies. The method depends on a computer-aided design model to build from, and is used both for rapid prototyping and, increasingly, for finished production parts.