8. Binder Jetting

Binder jetting methods were developed in the early 1990s, primarily at MIT. They developed what they called the 3D Printing (3DP) process in which a binder is printed onto a powder bed to form part cross sections. This concept can be contrasted with powder bed fusion (PBF), where a laser melts powder particles to define a part cross section. A wide range of polymer composite, metals, and ceramic materials have been demonstrated, but only a subset of these are commercially available. Some binder jetting machines contain nozzles that print color, not binder, enabling the fabrication of parts with many colors. Several companies licensed the 3DP technology from MIT and became successful machine developers, including ExOne and ZCorp (purchased by 3D Systems in 2011). A novel continuous printing technology was been developed recently by Voxeljet that can, in principle, fabricate parts of unlimited length.