Materials perspective of polymers for additive manufacturing with selective laser sintering

The fundamental factors of polymer powders, their importance for successful selective laser sintering (SLS) processing, and the outstanding position of polyamide 12 (PA12) powders in this connection are presented. Considering key factors, the combination of intrinsic and extrinsic properties necessary to generate a powder likely for SLS application is emphasized. Only a specific combination of indicated points leads to success. This is one reason for fewer materials commercially available to date for SLS application. PA12 and some dry blends based on PA12 are today the materials that are used to generate almost all commercial SLS parts. The specific performance of particular PA12 for SLS processing is unmatched from other polymers so far. Reasons are the precise molecular control of SLS polymers for thermal behavior (enlargement of sintering window) and the open chain structure. This is for generation of sufficient mechanical properties and to induce interlayer bonding of successively sintered layers to reduce anisotropic parts.