Powder Bed Fusion

This chapter presents the available powder bed fusion technologies for the processing of polymers. Selective laser sintering (SLS) is the most commonly used technique; the process involves the deposition of a powder layer and the use of a laser to selectively melt the region of interest. The 3D object is therefore produced with a layer-by-layer strategy. The increasing interest of both scientific and industrial communities for this technique has promoted its development, which nowadays is involved for the production of functional prototypes and a small series of components. An alternative and emerging technique is multi-jet fusion (MJF); differently from selective laser sintering, MJF uses an infrared (IR) radiation to promote the melting of thermoplastic polymers. Both these processes will be discussed in terms of required processing conditions, available materials and all the processing aspects which can influence the properties of the final component. Conclusively, some alternative technologies including selective mask sintering (SMS), high-speed sintering (HSS) and selective inhibition sintering (SIS) will be presented.