The rapid advancement of additive manufacturing (AM) technology and computational design techniques has unveiled a promising synergy between these two fields. The high print resolution achievable nowadays enables the pro-duction of intricate shapes, such as lattice structures, which can be further opti-mized through simulation-driven design techniques such as topology optimization (TO). This paper presents an optimization workflow that leverages field-driven design to employ the results of a TO to locally vary the diameter of lattice struc-tures, aiming for weight reduction and stiffness maximization. The process in-volves the automation of nTop design software via Python scripts to systemati-cally evaluate design variants and identify optimal solutions. The workflow steps are demonstrated through the application to a connecting rod and conclude with the evaluation of the achieved mechanical performance of the optimized compo-nent via Finite Element Method (FEM) analysis. Keywords: Additive Manufacturing, Topology Optimization, Lattice Structures, Field-Driven Design, Finite Element Method.

This work evaluates the influence of processing on the production of various cork composites. Cork agro-waste with different particle sizes, namely fine cork (FC, D_p < 250 µm) and coarse cork (CC, 1 mm < D_p < 2 mm), was valorized. It was possible to process composites containing up to 20 wt.% FC and 15 wt.% CC using a twin-screw extruder. These composites were subsequently manufactured via large-format additive manufacturing (LFAM) using fused granular fabrication (FGF). The effects of cork concentration and processing duration in the extruder on particle integration, as well as on the mechanical, physical, and thermal properties of the composites, were studied. As expected, a linear decrease in mechanical properties was observed with increasing cork content. For the same cork content and longer processing durations, properties were similar for FC and CC composites. Shorter processing durations in the extruder minimized degradation of FC. However, partial degradation occurred during FGF printing, leading to the formation of composite foams with increased porosity, lower density, and enhanced thermal insulation.

This study evaluates processing via fused granulate fabrication (FGF) of nanocomposites based on virgin polylactic acid (PLA) and thermomechanically reprocessed polylactic acid (rPLA), incorporated with 0 wt%, 5 wt%, and 10 wt% of silicon dioxide (${\mathrm{SiO}}_2$) nanoparticles. Rheological analysis revealed that rPLA exhibited a 42.4 % increase in melt flow rate compared to PLA, which can be attributed to thermomechanical chain scission occurring during reprocessing. At 10 wt% filler loading, the tensile strength along the XZ build direction tended to decrease. Scanning electron microscopy analysis suggests that this trend is related to nanoparticle agglomeration. Thermogravimetric analysis showed that adding 5–10 wt% ${\mathrm{SiO}}_2$ restored the lower initial thermal degradation onset of rPLA ($T_{5\%\mathrm{loss}}=313°\mathrm{C}$) to values equal to or exceeding PLA ($323–324°\mathrm{C}$), while overall crystallinity remained near 0% owing to rapid convective cooling during FGF printing. Short-term soil respirometry trials using extruded granule samples revealed that rPLA exerted a temporary respirometric inhibition, reducing soil basal respiration by 22.5%. The incorporation of 10 wt% ${\mathrm{SiO}}_2$ recovered 96.3% of the native soil metabolic activity by increasing extruded granules surface wettability and water availability at the particle interface. These findings demonstrate that the control of ${\mathrm{SiO}}_2$ loading enables the tuning of mechanical performance, establishing a framework for sustainable, large-format PLA components with tailored end-of-life properties.