## 1 Introduction
The best boards were those with the aspen-birch mixture, with values of mechanical properties (Modulus of Rupture--MOR, Modulus of Elasticity--MOE, and Internal bond--IB) close to birch veneer plywood. This research has shown that a mixture of two species provides better quality OSBs than single species usage [14]. Two strand boards with low density (aspen) and one with medium density (birch) were compared using strands with three lengths of 78, 105 and 142 mm and two chip thicknesses of 0.55 and 0.75 mm [15]. The best strengths (MOR, MOE, compressive strength, and IB) were obtained for birch and long and thin strands, demonstrating that high strengths are obtained from softwood with a low or medium density. The mixture of three chip types (red cedar, eucalyptus, and pine) for OSBswas investigated. Research by this author [16] showed that eucalyptus can replace the more expensive pine wood, but red cedar reduces its mechanical properties. Another group managed by [PERSON] [17] evaluated the influence of chip length on OSBs made from _Pinus taeda_ species. The results showed that the obtained board's properties exceeded the requirements of the EN 310:1999 [18] standard, and the increase in the length of the strands positively influenced the properties of the obtained boards. Other authors [19] have investigated the influence of the juvenile wood of _Pinus radiata_ D., the chips being obtained from several 26-year-old trees in Chile. There was a strong influence of strands of juvenile wood after exceeding the proportion of 70%, which means it is a challenge to use this type of wood in the composition of OSBs. [PERSON] and [PERSON] [20] proposed a heat treatment of an OSB of pine chips produced in the laboratory as a method of dimensional stabilization in order to reduce hygroscopicity and eliminate pressing stresses. A heat treatment, similar to the fibreboard defibration procedure, was performed at 250 \({}^{\circ}\)C for three periods of 4, 7, and 10 min, and the results obtained from the research showed that the swelling in thickness, water absorption, and equilibrium humidity was significantly reduced. [PERSON] and his group [21] found a process for modeling a bamboo OSB from the point of view of the modulus of elasticity on the major and minor axes. [PERSON] and group [22], as a solution, replaced mature softwood species with juvenile woods and used castor oil-based polyurethane an adhesive. All determinations were in accordance with EN 300:2006 [2] and showed higher strengths than the reference ones; the boards made of high-density species showed better physical performance, and the boards made of wood species with higher density, added little by little, had high mechanical properties. The [PERSON] group [23] investigated the influence of three fast-growing tropical species on OSB/1 boards, with a predilection for mechanical properties and dimensional stability. The result was that the boards derived from the combination of high-density species and other species with low density had better dimensional stability than those produced from a single species. [PERSON] and his group [24] demonstrated the potential of two low-density tropical species when used in making OSBs, using castor oil polyurethane resin as the adhesive. All the boards obtained were classified in the OSB/4 category (EN 300), namely, boards with high mechanical strength and low hygroscopicity. [PERSON]'s group [25] investigated the mechanical properties of OSBs made of small-diameter logs of pine and willow containing substantial portions of juvenile wood. The researchers showed that with the increase in chip thinness, the internal bond increased by up to 20%. They investigated the effect of wood species and the orientation of chip layers by creating three types of orientations [26]--perpendicular, parallel and random--and the use of three wood species with anhydrous wood densities of 0.36, 0.41 and 0.46 g/cm\({}^{3}\). OSBs made from lower density wood species had better mechanical properties and high dimensional stability.