## 3 Results
### Analysis of Mechanical Properties of OSBs  
A comparative assessment of the MOR and MOE properties of OSBs by the implementation of interval plots with 95% CI indicates that the differencesare not significant.  
Analyzing the MOR properties, the estimated average value for OSBs from softwoods is 54.50 N/mm\({}^{2}\), with 43.48 N/mm\({}^{2}\) for hardwood OSBs. From the point of view of the estimated median, the difference between them shows that the MOR properties of the softwood OSBs are superior to the MOR properties of the hardwood boards, with a difference of 25.3%. Similar results were obtained by other authors [15]. Additionally, the confidence interval of MOR values for softwood OSBs shows a high variance of data comparing to hardwood OSBs (Figure 4a).  
Figure 3: Interval plot of analyzed properties for OSB types: (**a**) swelling; (**b**) absorption.  
Regarding the MOE properties, the hardwood OSBs present superior MOE values, with a mean of 7253 N/mm\({}^{2}\), while softwood OSBs reveal lower properties (MOE = 5780 N/mm\({}^{2}\)). This fact is shown by the estimated mean values for the analyzed types of OSBs (Figure 4b).  
The comparative analysis of the MOR and MOE properties that are specific to the major and minor axes is presented graphically in Figures 5 and 6. Analyzing the modulus of rupture, it can be observed that the obtained values exceed the specified value of OSB/3-Krono. Additionally, higher values were obtained for OSBs made of mixed softwood species.  
Figure 4: Interval plot of analyzed properties for OSB types: (**a**) modulus of rupture (MOR); (**b**) modulus of elasticity (MOE).  
In the case of the modulus of elasticity of different types of manufactured OSBs, it can be seen that the modulus of elasticity at static bending on the major axis exceeded a value of 4000 N/mm\({}^{2}\), the manufactured board from the mixture of hardwood having the maximum value of 7110 N/mm\({}^{2}\) (Figure 6).  
Outdoor OSBs are usually tested by internal bond, both for dry boards and for boards boiled in water for 2 h.The interval plot of internal bond properties for analyzed OSBs indicates that hardwood OSBs display higher IB properties than softwood OSBs. High values of mean (1.57 N/mm\({}^{2}\)) and median (1.629 N/mm\({}^{2}\)) for IB properties were estimated in the case of mixed hardwood OSBs. Based on the estimated statistical parameter and interval plots with 95% CI, the analysis indicates that the difference is not significant (Figure 7).  
Figure 5: MOR of OSB panels from mixed species compared to OSB/3–Krono.  
Figure 6: MOE of OSB panels from mixed species compared to OSB/3–Krono.  
The diminishing strength of the internal bond after boiling in water was different from one group of species to another, as seen in Figure 8. It is observed that the decrease in IB was 38% for the softwood species mixture and 28% for the hardwood species mixture. These small differences show that the loss of strength by boiling does not depend on the group of species, but on the adhesive and other hydrophobic substances used. In this paper, the same adhesive recipe was used for all analyzed OSBs, which is why the adhesive factor was removed from the analysis. Additionally, in the case of these determinations, the obtained experimental values exceeded the minimum values of the Kronospan factory (OSB/3), and they are similar to the values obtained by other authors [26].