## 4 Discussion  
An overview of the mechanical tests performed on the compounds under investigation and the pure PLA polymer is shown in Figure 14. The characteristics regarding the mechanical properties of the material were consistently improved by the addition of various glass particles. The improvement in the mechanical performance caused by the addition of glass particles in different forms (beads, flakes, and powder) may also be influenced by the interactions occurring at the interface between the particles and the matrix [72]. As can be observed in Figure 14, in the majority of the investigations, the PLA/Glass Beads with 3.0 wt.% concentration displayed the highest mechanical response. Particularly, the specimens made with PLA/Glass Beads 3.0 wt.% show notable increases in their flexural properties, including strength and toughness. Additionally, the tensile stiffness has improved significantly. The specimens containing PLA/Glass Flakes 6.0 wt.% show a considerable increase in both the tensile strength (\(\sigma_{\text{B}}\)) and stiffness when examining the impact of the same type of glass additives. No other mechanical parameter was adversely impacted by the addition of the glass particles, with the exception of the impact strength, which decreased as the filler concentration reached 9.0 wt.%. In conclusion, the unfilled PLA polymer was surpassed in the majority of the investigations, even by the composites with the greatest loading of 9.0 wt.%, which showed superior values in their mechanical properties. A number of important insights can be gained from the investigation of the microstructure of the 3D-printed samples, especially from their side surface. It enables the assessment of critical data, including the thickness of each printed layer and the general calibration of the 3D printing procedure. Additionally, this study can reveal significant features of the interfaces between the layers and evaluate the strength of their bonding and fusion. SEM pictures demonstrate that, in comparison with pure PLA, the addition of glass fillers to the  
Figure 14: The mechanical characteristics of the examined 3D-printed samples are depicted in the left-side spider diagram. The performance of the pure PLA, which was produced and tested as a benchmark for assessing the acquired improvement, is represented by the gray region. The materials showing the highest mechanical reaction in each experiment are listed in the table on the right. Each compound is presented in a different color according to the legend provided. PLA matrix does not result in the creation of voids on the surface of the 3D-printed samples. It is important to note that there are slight imperfections in the layer-fusing when the layer shape is uneven. The mechanical performance of the composites was unaffected by the 3D printing structure's imperfections, such as minor flaws in layer fusing and irregular layer shapes. This suggests that the mechanical response of the composites is not adversely affected by these flaws. It is important to note that TGA analysis shows that the materials used in the MEX procedure are not harmed by the processing temperatures used. This is important since it guarantees that material deterioration will not have a negative impact on the 3D printing process as a whole or the mechanical performance of the samples made using the generated composites. It is also notable that practically every concentration of each glass component consistently improved the mechanical characteristics of the PLA polymer. This demonstrates how adding glass additives has a favorable impact on improving the PLA polymer's mechanical performance. The use of glass additives as reinforcement agents for polymers in 3D printing is currently being studied, while as was mentioned in the literature review section, research is still limited. Nonetheless, it shows that efforts are being made to utilize the advantages of glass additives for improving the functionality of polymers in the context of 3D printing.