What AM method melts build material and then uses nozzles to dispense it in layers on a build platform?

The method that melts build material and uses nozzles to dispense it in layers is known as material extrusion. In material extrusion, a thermoplastic or thermoset filament is heated until it reaches a molten state and then pushed through a nozzle onto a build platform. As the material is extruded, it solidifies, allowing for layer-by-layer construction of the object. This technique is widely used in 3D printing, particularly in fused deposition modeling (FDM), where precise layering is crucial for building complex geometries.

This process contrasts with other methods. For instance, material jetting deposits droplets of material that are instantly cured or solidified, rather than melting and layering. Powder bed fusion, on the other hand, involves the use of a laser or electron beam to fuse powdered material together without the use of nozzles, and binder jetting uses a liquid binding agent to bond particles in a powder bed, which is quite different from the nozzle-based approach seen in material extrusion.