FDM is the most widely available 3D printing process, mainly used for low-cost prototyping and design verification with very fast turn around times.
The FDM printing process starts with a string of solid material called the filament. This line of filament is guided from a reel attached to the 3D printer to a heated nozzle inside of the 3D printer that melts the material. Once in a melted state, the material can be extruded on a specific and predetermined path created by the software on the computer. As the material is extruded as a layer of the object on this path, it instantly cools down and solidifies – providing the foundation for the next layer of material until the entire object is manufactured.