Additive Manufactured Parts Produced Using Selective Laser Sintering Technology: Comparison between Porosity of Pure and Blended Polymers

Abstract

For different manufacturing processes, porosity occurs in parts made using selective laser sintering (SLS) technology, representing one of the weakest points of materials produced with these processes. Even though there are different studies involving many polymeric materials employed via SLS, and different manuscripts in the literature that discuss the porosity occurrence in pure or blended polymers, to date, no researcher has reported a systematic and exhaustive comparison of the porosity percentage. A direct comparison of the available data may prove pivotal in advancing our understanding within the field of additively manufactured polymers. This work aims to collect and compare the results obtained by researchers who have studied SLS's applicability to different amorphous or semi-crystalline polymers and pure or blended materials. In particular, the porosity values obtained by different researchers are compared, and tables are provided that show, for each material, the process parameters and the measured porosity values.

Keywords: 3D printing; additive manufacturing; blended polymers; porosity; pure polymers; selective laser sintering.

Figure 1

Schematic of an SLS machine’s main components (reprinted from [18]).

Figure 2

Porosity in SLS parts with respect to processing parameters.

Figure 3

Polymer powders commercially available for SLS. Reprinted from [10].

Figure 4

Comparison between (a) porosity and (b) equivalent pore diameter distribution available in the literature [25,36,42,47].

Figure 5

Porosity as a function of energy density. The graph was obtained by grouping all the data available in the literature for PA12.

Figure 6

Porosity average value found in the literature for (a) semi-crystalline polymers and (b) amorphous polymers and elastomers.