## 2 Materials and Methods  
### Preparation of Specimens for Tensile and Impact Testing  
The fiber volume fraction (\(V_{f}\)) in a composite material represents the fiber volume ratio to total composite volume, directly influencing its mechanical properties. Figure 2 shows natural jute fiber with a mesh-type weave or 90/0\({}^{\circ}\). Manufacturing proportions for jute fiber-reinforced epoxy matrix composites is shown in Table 1. From here on, only the jute fiber volume content is present, considering the complement percentage of epoxy volumetric content in the composite composition. It is determined using the densities and masses of both fiber and matrix, assuming minimal void content [21]. The calculation is as follows in (1):  
\[V_{f}=\frac{\frac{m_{fiber}}{\rho_{fiber}}}{\frac{m_{fiber}}{\rho_{fiber}}+ \frac{m_{fiber}}{\rho_{resin}}} \tag{1}\]  
where \(m_{fiber}\) and \(m_{resin}\) are the mass of fiber and resin, respectively. In addition, \(\rho_{fiber}\) and \(\rho_{resin}\) are the density of fiber and resin, respectively.  
Figure 2: Natural jute fiber with a mesh-type weave or 90\({}^{\circ}\)/0\({}^{\circ}\).  
Different amounts of jute fiber reinforcement layers were used based on the target volumetric fraction of the composite, as detailed in Table 1. Each layer consisted of a textile sheet measuring 15 \(\times\) 20 cm\({}^{2}\). The fabrication of the composite materials was carried out using the hand lay-up process, a technique widely employed for the production of small-batch laminated structures. East Coast Resin epoxy resin was used, with an average density of 1.15 g/cm\({}^{3}\), for jute fiber with a density of 1.35 g/cm\({}^{3}\). The system consists of the resin (component A) and the hardener (component B), which must be mixed according to the manufacturer's specified ratio. The recommended mixing ratio is 1:1 by volume, meaning one part resin to one part hardener.  
Process Description  
The manufacturing and evaluation processes for jute fiber-reinforced epoxy matrix composites is described and illustrated in Table 2. This manufacturing and evaluation method allows for a comprehensive comparison of jute fiber composites at different volumetric proportions showed in Figures 3 and 4, providing a detailed understanding of how these variations affect the mechanical properties of the composite material.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Step** & **Process** & **Image** \\ \hline
1 & Jute fibers were immersed in a solution of alcohol, distilled water, and ice for 24 h to remove impurities. & \\ \hline
2 & A mold was constructed using ASTM A36 steel and Shielded Metal Arc Welding (SMAW). & \\ \hline
3 & Jute fibers were cut to the dimensions of the mold, polyvinyl alcohol was applied to the mold, and epoxy resin was prepared and applied along with the layers of fiber. The mold was closed and taken to the compression press for 72 h. Finally, demolding was performed. & \\ \hline
4 & Each composite plate with a specific volume of jute fiber was cut using CNC. & \\ \hline
5 & Tensile and impact testing specimens were cut from each plate. & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of processes for the manufacture and evaluation of jute fiber and epoxy matrix composites.