## 3 Results and Discussion
### Characteristics of OSB Boards
#### 3.1.4 IB Results  
The internal bond of the OSB boards was over 0.87 N/mm\({}^{2}\) for the dry boards and over 0.6 N/mm\({}^{2}\) for the boiled boards in water for two hours (Figure 12). It is observed that the fast-growing boards (willow and poplar) have values up to 34% higher than the two species of resinous (pine and spruce). The obtained values correspond to the values described by other authors [6], but also with those imposed by the companies that produce their own products [32].  
Table 2 shows a centralization of all the characteristics of the OSB boards. At first glance, it is not possible to see very clearly which of the four types of boards are better or worse, for which the same hierarchical algorithm was applied as for the strands (Figure 7).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Specie**} & **Density, kg/m\({}^{3}\)** & **MOR 1** & **MOE 1** & **MOR 2** & **MOE 2** & **IB 1** & **IB 2** \\  & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** & **N/mm\({}^{2}\)** \\ \hline \hline  & 726.7 & 40.7 & 6623 & 26.9 & 2807 & 1.2 & 1.0 \\ \hline  & 725.9 & 44.5 & 4732 & 36.0 & 4611 & 1.3 & 1.1 \\ \hline  & 637.2 & 20.5 & 3404 & 32.0 & 3913 & 1.1 & 0.6 \\ \hline  & 585.7 & 30.6 & 3886 & 24.7 & 3020 & 0.8 & 0.6 \\ \hline \hline  & & & & & & & \\ \end{tabular}
\end{table}
Table 2: OSB boards characteristics.  
Figure 11: Modulus of elasticity (MOE) for the willow, poplar, spruce, and pine OSB boards on major and minor axis.  
Figure 12: Internal bond for OSB dried and boiled boards.  
Based on the above used algorithm, a number of different points were found from one board to another and the hierarchy was obtained, taking into account the seven characteristics of the OSB boards, respectively: density, MOR on major axis (MOR 1), MOE on major axis (MOE 1), MOR on minor axis (MOR 2), MOE on minor axis (MOE 2), IB on dried sample (IB 1), and IB on boiled samples (IB 2). In addition to the hierarchy of OSB boards chip characteristics were also tested, which can be seen in Figure 13.  
It is observed that there is an almost perfect parallelism between the linear regression curves (Figure 13). The two coefficients of the linear equations m\({}_{1}\) = 4.7 = tg\(\alpha_{1}\) and m\({}_{2}\) = 4.8 = tg\(\alpha_{2}\) offer two angles of 77.99 degrees and 78.23 degrees, respectively a difference of only 0.24 degrees.  
The general conclusion of the above analysis is that there is an almost perfect correlation between the characteristics of the chips and the characteristics of the corresponding OSB boards. Also, from the entire study carried out in the paper, it is concluded that the species of fast-growing hardwood offers OSB boards with characteristics much better than the classic species of softwoods, and especially the pine. Such a new approach is needed for wood species used in the manufacture of OSB boards, by increasing the raw material base of this technology, respectively by adding new wood species (poplar and willow) cheaper and with superior properties in obtaining OSB boards. In fact, other authors have found that from the species of hardwood trees, OSB boards are produced and have some mechanical properties superior to those obtained from pine [4; 26].