Fused deposition modeling (FDM) is an additive manufacturing technology commonly used for modeling, prototyping, and production applications as trademarked by Stratasys Inc.. It is one of the techniques used for 3D printing.
FDM works on an "additive" principle by laying down material in layers;
a plastic filament or metal wire is unwound from a coil and supplies
material to produce a part. Thus, FDM is also known as a solid-based AM
Schematic representation of the 3D printing technique known as Fused Filament Fabrication; a filament a) of plastic material is feeded through a heated moving head b) that melts and extrudes it depositing it, layer after layer, in the desired shape c). A moving platform e) lowers after each layer is deposited. For this kind of technology additional vertical support structures d) are needed to sustain overhanging parts.