Which of the following describes a key process in FDM?

In Fused Deposition Modelling (FDM), a key process involves the use of a temperature-controlled head that extrudes thermoplastic material. This is central to how FDM operates, as it relies on the precise application of heat to melt thermoplastic filament and then extrude it through a nozzle. The extruder moves in multiple directions, laying down the melted material layer by layer to build the desired 3D object.

This method allows for significant control over the printing process, enabling adjustments in temperature and flow rate, which can significantly affect the quality and adhesion of the layers. Additionally, by controlling the temperature of the head, the filament can be kept at optimal melting temperatures to ensure a consistent extrusion process, which is vital for achieving good layer bonding and overall structural integrity in the final print.

In contrast, other options involve processes not typical of FDM. For instance, a laser melting plastic is more associated with Selective Laser Sintering (SLS), while inkjet systems are related to material jetting technologies, and the creation of a mold before printing aligns more closely with traditional manufacturing methods rather than additive processes like FDM, where objects are built layer by layer without the need for a pre-existing mold.