Tensile properties and sustainability assessment of vat photopolymerization 3D printed components with recovered plastic filler

Abstract

Raw material production represents one of the major issues of additive manufacturing as it can be an expensive and environmentally impactful phase. One example is provided by the light-curing resins used in vat photopolymerization processes. To this purpose, this study aims at evaluating the use of recovered polyamide powders as filler for photocurable resins from different perspectives; to this purpose, tensile tests were performed in order to evaluate the effect of recovered powder content as filler on the mechanical properties of the resin. Furthermore, a scanning electron microscopy and computed tomography analyses were carried out to investigate the fracture mechanisms and dispersion of the filler within the resin. Finally, a life cycle assessment analysis was performed to evaluate the effect of different reused power contents as filler on the environmental impact of 3D printed components. Results showed that the use of recovered powder as filler for light-curing resin in vat photopolymerization 3D printing parts allows the obtaining of an improvement in terms of tensile strength and elastic modulus up to 62% and 107%, respectively. In addition, a reduction in environmental impacts up to 48% was obtained. A homogeneous dispersion of the particles within the resin was observed at the different filler contents investigated.

Investigating the Characteristics of Nano-Graphite Composites Additively Manufactured Using Stereolithography

“…The significant increase in gel content at higher NG concentrations (5%) is an intriguing result, as it suggests potential brittleness and property reduction, which aligns with the observed decrease in tensile and bending loads. This phenomenon has been observed in other polymer composite systems, where excessive filler content can lead to agglomeration, stress concentration, and premature failure [ 38 ].…”