## 4 Results and Discussion
Subsequent tests showed an average Young's modulus of 4.48 \(\pm\) 0.13 MPa compared to 5.41 \(\pm\) 0.23 MPa obtained following manufacturing with the intermediate plates. Similarly, the tensile strength rose from 43.41 to 53.86 MPa. This improvement in the manufacturing process is also visible in the rupture mode of the specimen which switches from delamination in the fibers' layer for the sandwich method to clean rupture for the stratified method (Figure 12). It should also be noted that no bulging deformation was observed during the manufacture with the intermediate plates, in contrast to the sandwich method, thanks to a better distribution of the fibers in the thickness of the plate. Figure 13 below shows the composition of the plates in their thickness by each of the two assembly methods. We can easily discern strata in the sandwich composite, whereas with the intermediate plate method, the composite is visually homogeneous with fibers well distributed across the width. Figure 12: Visualization of fracture defects (delamination) on sandwich tensile specimens. Mechanical performance tests confirm that this method provides better resistance. However, it is also more time-consuming in terms of preparation since it requires about thrice the time required for the sandwich method. Table 5 compares the main mechanical characteristics of the PLA/nettle composite obtained by the intermediate plate method to results from the literature. We notice that our results with 10% mass ratio fibers are better than those mentioned in the literature for identical compositions. The results are even better than those with higher fiber content. The chemical treatment seems to be beneficial for the elongation properties of tensile strength, and fiber content on the improvement of mechanical properties up to different percentages according to the authors. The obtention process, for these authors, also has a great influence. Moreover, the structural form of reinforcement, for example, fabric, yarn, fiberweb, etc. played a decisive role in determining the mechanical properties of bioconposite. We believe that our results are mainly due to the manufacturing technique used for our specimens. The technique of combining film stacking and hot pressing, but with thicker plates than the films and by refining the pressure, the temperature, and the holding time, has resulted in not only good mechanical properties but also low waste, reduced part cost, uniform pressure distribution on the composite and good surface finish [45]. Figure 13: Comparison of specimens (side view) obtained by the sandwich method (**a**) and intermediate plate method (**b**) after testing. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Composite** & **Obtention Process** & **Fiber Length** & **Treatment** & **Fiber (Mass** & **Young’s** & **Tensile** & **Elongation at** \\  & & **(mm)** & **Ratio** & **(GPa)** & **(MPa)** & **Break (\%)** \\ \hline Present & & & & & & \\ studyPLA/nettle & Intermediate plate & 10 \(<\) L \(<\) 70 & - & 10 & 5.41 \(\pm\) 0.23 & 53.98 \(\pm\) 3.11 & 1.24 \(\pm\) 0.05 \\ \hline nettle/PLA [39] & & & & & & & \\ fibers carded and & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline nettle/PLA [42] & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline nettle/PS [43] & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline ramie/PLA [36] & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline ramie/PLA [38] & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline nettle/PLA [44] & & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\ \hline nettle/PP [32] & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of the mechanical properties of the obtained PLA/nettle composite with literature results. Additional tests were also performed at a velocity of 20 mm/min (Figure 11) to evaluate the viscoplastic behavior of the composite.