ABSTRACT
Extrusion-based Additive Manufacturing (AM) processes and their details are covered in this chapter. These utilize the basic principle of forcing pressurized semi-molten material out from a nozzle at either continuous or variable rates to obtain layers after their complete solidification. Bonding of these layers occurs till the complete artefact is obtained. A variety of basic steps characterize any extrusion-based process, including material loading which is done from a chamber and liquefying by means of heat, pressurizing, extruding from a nozzle, plotting, its bonding and finally incorporating support structures. Fused deposition modelling, which was initially proposed by S. Scott Crump around 1980s and commercialized by Stratasys, is an extremely popular and robust AM technique since complicated parts can be obtained in reasonable time. Like other AM techniques, it requires no tooling and minimal human interference. This can be used to obtain models, prototypes as well as end parts and is based on the layered AM principle.
