## 2 Materials and Methods
### Manufacturing Process  
This study presents a new manufacturing system developed to reduce the elaboration time and simplify the process. This structure is placed over the sample mould and moved along the sample on rails with a pouring hopper to homogeneously distribute the plaster. Through a four-step process, the sample is produced. Figure 2 shows, in a longitudinal cross-section, the distinct parts of the machine.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Name** & **E-35 Plaster (g)** & **Water (g)** & **Perlite (g)** & **RGW Layer (N\({}^{\circ}\) of Layers)** & **Configuration** \\ \hline E-0.7 & 1000 & 700 & - & - & **(A)** \\ E-0.7-P & 850 & 595 & 50 & - & \\ E-0.7-1 LU & 1000 & 700 & - & 1 & **(B)** \\ E-0.7-P-1 LU & 850 & 595 & 50 & 1 & \\ E-0.7-2L & 1000 & 700 & - & 2 & **(C)** \\ E-0.7-P-2L & 850 & 595 & 50 & 2 & \\ \hline \hline \end{tabular}  
* To conduct this study, different-sized samples were established within the context of the tests performed. Samples were elaborated according to the EN 13279-2:2014 Standard [40]. The tests performed and samples used in each test are shown in Table 3.  
\end{table}
Table 2: Samples dosages, composition, and configuration. Weight in grams.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Samples** & **Tests** \\ \hline \hline \multirow{4}{*}{\(15\times 15\times 2\) cm\({}^{3}\)} & To set thermal conductivity value following Guarded Hot plate method using a \(\lambda\)-Meter EP500e from Lambda-Méßtechnik GmbH Dresden (Dresden, Germany), according to EN 12664 and EN 1946-2 standards [41, 42].  
\begin{tabular}{c c} \hline \hline \multirow{4}{*}{\(24\times 24\times 2\) cm\({}^{3}\)} & To set thermal conductivity value using the heat flux meter (HFM) method according to EN 12664 and EN 1946-3 [42, 43] standard.  
\begin{tabular}{c c} \hline \hline \multirow{4}{*}{\(30\times 40\times 2\) cm\({}^{3}\)} & Impact, surface hardness, and flexural strength tests to determine mechanical and complementary physical properties requires by EN 12859:2012 and EN 14246:2007 [44, 45] standards. For this, Proeti, S.A., (Madrid, Spain) bending test equipment was used.  
\end{table}
Table 3: Samples size and tests performed.  
The four-step process is shown in Figure 3 and consists of the following:  
* Step 1: The structure is placed such that the pouring spout is at the beginning of the mould. Plaster is then poured into the hopper and as it falls, the structure moves along the mould until it reaches the end, creating the first layer.
* Step 2: The middle layer material is placed on the roller.
* Step 3: The structure moves back until it reaches the beginning while the middle layer is being laid. The weight of the roller presses down on the middle layer material, thus ensuring a homogeneous placement.
* Step 4: Plaster is again poured into the hopper and as it falls, the structure moves along the mould until it reaches the end, creating the second layer. Optionally, a second roller, provided with kraft paper, can be placed and used for a more attractive finish and extra bending strength.  
Figure 3: Four-step elaboration process.  
Figure 2: Cross-section of the manufacturing system developed.  
After Step 4, the structure is placed outside the mould. Once the sample is set, the framework is removed and sample is taken out of the mould to let it dry.