PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 12, Number 1, 2026
of different structural characteristics, including the thickness of surface/core layer, strand’s size and strand’s thickness. Large strands are used in the top/bottom layer of all types of boards. Their physical and mechanical properties were investigated. The results show that the density of the core layer increases with decreasing the size of strands. The orientation angle difference between large (length 150 ± 5 mm×width 35 ± 5)mm) and medium (length 75 ± 5mm × width 20 ± 2mm) strands is slight. The modulus of elasticity (MOE) and modulus of rupture (MOR) of all types of boards along major axis are higher than 6500MPa and 45MPa respectively. Small strands (length 2 ± 1mm × width 1 ± 0.5mm) in the core layer significantly decrease the MOR along the major axis. The MOE and MOR along the minor axis decrease because of small strands in the core layer and thin core layer. Small strands in the core layer are conducive to enhancing the internal bond strength (IB), while thin strands in top/bottom layer significantly decrease the IB. Small strands in the core layer significantly decrease the 24h thickness swelling. A thin core layer indicates to low screw holding capability in the side face of boards. The outputs of this study contribute to optimizing the production and application strategies of OSB. “In-situ investigation of the VDP formation of oriented strand board”, Wanzhao Li, Yunfeng Shi, Jipeng Zhou & Changtong Mei, European Journal of Wood and Wood Products , Vol.84, article number 32, (2026). Oriented strand board (OSB) is an important engineered wood product manufactured through bonding of wood strands in cross-oriented layers. Vertical density profile (VDP) is one of the key factors determining both physical and mechanical properties of OSB. To understand the formation of VDP, VDP of the mattress was monitored by recording the position of strands during the hot-pressing. Three types of boards were manufactured in the lab in terms of different hot-pressing curves, namely board a (pressed at 1.5MPa and 3.5MPa), board b (pressed at 3.5MPa without pre-heating), and board c (pressed at 3.5MPa with 3min pre-heating). It finds that the actual and predicted densities are significantly similar (R > 0.8). Boards a and b have conventional M-shaped VDP, while VDP of board c is more uniform. For all three types of boards, as increasing pressure, density of the top and bottom layers instantly increases, while the density increase in core layer is slow. The density curve in core layer could be fluctuating, especially in board a and it tends to be smoother with decreasing pressure. Density in each layer of the board decreases with decreasing pressure, especially in boards a and b. The VDP mainly affects MOE and MOR of the boards in major axis. Board b has the highest MOE and MOR, while board c has the lowest MOE and MOR. Board c owns the highest IB strength and the lowest 24 h thickness swelling. Understanding the VDP formation would contribute to optimizing the production and application of OSB. “Characteristics of secondary fibres derived from recycling processes of fibreboard manufacturing residues and post-consumer wood waste”, Changling Xu, Percy Alao, Triveni Soubam, Joran van Blokland, Stergios Adamopoulos, Materials Today Communications , Vol.51, Feb. 2026, 114784. Recycling of post-consumer fibreboards has gained significant traction in both academic research and industrial applications. The quality of secondary fibres plays a crucial role when reusing them in fibreboard production. This study presents a comprehensive analysis of recycled (hereafter referred as secondary) fibres recovered through modified thermo-mechanical pulping and steam treatment methods, in comparison to virgin fibres. The fibres were systematically characterized in terms of their physical, chemical, and morphological properties, supplemented by microscopic analysis. Results showed that the average fibre length of steam-treated secondary fibres derived from post-consumer fibreboards and fibreboard production (processing) residues was comparable to that of virgin fibres, whereas secondary fibres from solid wood waste were 18 % shorter due to identified presence of hardwood species. All
Technical Abstracts
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