A review of aging, degradation, and reusability of PA12 powders in selective laser sintering additive manufacturing - ScienceDirect

For example, the flowability of the polymer, as quantified by the melt flow index (MFI), decreases with the increasing number of recycles/runs (see Fig. 9a) due to the increasing melt viscosity which can deteriorate the mechanical properties and surface finish of the 3D printed parts (see Fig. 9b) [45]. Additionally, various phenomena such as thermal oxidation, degradation and crosslinking of polymer powders during aging can alter their mechanical properties and surface characteristics [89]. In contrast, improvements in the mechanical properties were reported when a mixture of used and virgin powders was utilized as the feedstock for SLS [91]. In accordance with previous findings, powder reuse was shown to impact size distribution, sphericity distribution, and surface morphology of polyamide particles. More specifically, reuse includes repeated expansions/shrinkages in the heating and cooling cycles, which alters the surface morphology of reused polyamide particles and shows increased

For example, the flowability of the polymer, as quantified by the melt flow index (MFI), decreases with the increasing number of recycles/runs (see Fig. 9a) due to the increasing melt viscosity which can deteriorate the mechanical properties and surface finish of the 3D printed parts (see Fig. 9b) [45]. Additionally, various phenomena such as thermal oxidation, degradation and crosslinking of polymer powders during aging can alter their mechanical properties and surface characteristics [89]. In contrast, improvements in the mechanical properties were reported when a mixture of used and virgin