European Journal of Wood and Wood Products最新文献

The circular economy promotes the use of industrial by-products as raw materials for high-quality products. Silver fir bark (Abies alba Mill.), a low-value residue from wood processing, is a rich source of polyphenols with antioxidant properties. This study investigated how bark preparation (particle size) and storage conditions affect the content of total extractives, polyphenols, and condensed tannins in aqueous extracts over a 10-month period. Bark samples of two particle sizes were stored either outdoors (exposed to precipitation) or indoors (dry, dark conditions). The extracts were analyzed monthly by gravimetry and UV-Vis spectrophotometry. The results showed that both particle size and storage conditions significantly influenced the retention of extractives and polyphenols in the samples. The highest losses occurred in ground bark samples stored outdoors, while the best retention was achieved with larger bark particles stored in a covered, dry environment. These findings highlight the importance of optimized storage strategies for the preservation of bark quality as a source of bioactive compounds.

The valorization of agricultural waste has gained increasing attention in recent years, with orange peel waste emerging as a promising precursor for activated carbon (AC) production. This study investigates the production of AC from orange peel waste using zinc chloride (ZnCl₂) as a chemical activator and evaluates its impact on the physical, mechanical, and environmental properties of three-layer particleboards. AC was incorporated into the urea–formaldehyde (UF) adhesive at 0.5–1.5% by weight and applied to both surface and core chips, ensuring its distribution across all three layers of the particleboard. The AC exhibited a specific surface area of 572.14 m²/g and a total pore volume of 0.280 cm³/g, demonstrating its high porosity and adsorption capabilities. Mechanical test results of particleboard indicate that the inclusion of 1.5% AC increased MOR by 26% (from 10.02 N/mm² to 12.65 N/mm²) and MOE by 52% (from 1083.83 N/mm² to 1645.33 N/mm²), while IB rose from 0.41 N/mm² to 0.53 N/mm². Additionally, formaldehyde emissions of particleboard decreased significantly from 11.25 mg/100 g (control) to 8.01 mg/100 g at production (0th month) and further to 3.20 mg/100 g after 12 months. Based on TS EN 312 (2012) classification, the AC-modified panels at 1.0–1.5% met the requirements of P2 boards for general-purpose use in dry conditions, while also complying with the E1 formaldehyde emission standard. The orange peel waste-derived AC can serve as an effective additive in composite materials, simultaneously improving mechanical performance and meeting international environmental and safety standards.

This study presents both experimental tests and numerical analyses to predict the dynamic structural behavior of birch plywood sheets under impact conditions. The comparison between the ballistic curves and ballistic limits obtained numerically and experimentally highlights the accuracy of the model in simulating the material response. Birch plywood, with its multilayer cross-laminated structure, demonstrates excellent impact resistance, effectively distributing and dissipating the applied forces. This configuration significantly reduces crack propagation and enhances energy absorption, making it a robust material for dynamic loading conditions. The paper introduces a detailed model for the ply fabric material of birch plywood, along with a comprehensive set of material parameters, providing a solid foundation for further research and application. The numerical analysis of the average impact force across the range of impact velocities considered offers valuable insights into the material performance. These findings further validate the suitability of birch plywood for structural applications requiring impact resistance. This work contributes to a deeper understanding of the material dynamic behavior and advances the knowledge of engineered wood products in impact-related contexts, paving the way for more informed decisions in material selection for demanding structural applications.

The demand for engineered wood products for construction and the climate change affecting some forest plantations impacts the need for diversifying the matrix of wood species apt for structural applications, which is nowadays focused on a few softwood species. Hardwoods have been considered all over the World by the scientific community and industry players with a special focus on hardwoods such as chestnut, oak, birch, maple, and beech. The present article addresses the experimental assessment of the mechanical and bonding performance of glulam beams made by European beech (Fagus sylvatica L.) from Spain. A total of 48 glulam beams (homogeneous and combined) have been produced at the laboratory facilities (20 without finger joints and 28 with finger joints). Non-destructive tests were previously considered to characterize the raw material using a longitudinal vibration method (Machine Timber Grader), also applied to the glulam beams before the failure test. For the prediction of the mechanical properties (modulus of elasticity), the Transformed Section Method and Longitudinal Vibration Method were considered. Correlation coefficients of 0.90 or higher have been obtained. Additionally, 41 lamellas with finger joints have been characterized by tension, resulting in a characteristic tensile value of 50.8 MPa. Its influence on the bending properties of the glulam beams has been evaluated, obtaining a characteristic bending strength value of 52.9 MPa. In general, a good bonding performance has been obtained for both Method A and Method C protocols from the European standard of glulam manufacturing (EN 14080).

Noise pollution is a growing concern in urban environments, driving the need for sustainable and effective acoustic materials. Wood, a naturally abundant and lingocellulosic material, exhibits sound absorption properties influenced by its porosity, gas permeability, and structural integrity. This study aimed to investigate the relationship between these properties and the sound absorption coefficient (SAC) of five wood types: Coconut (Cocos nucifera L.), Hackberry (Carya ovata), Malas (Homalium foetidum Roxb.), Oak (Quercus mongolica Fisch.), and Paulownia (Paulownia tomentosa). Using the two-microphone transfer function method, SAC was measured across a frequency range of 250–4000 Hz, both with and without back air cavities (0–4 cm). Additional analyses included porosity determination via helium pycnometer, gas permeability using a capillary flow porometer, and surface morphology assessment with a 3D optical profilometer. Results showed that back air cavities significantly enhanced low-frequency SAC. Hackberry and Oak achieved the highest Noise Reduction Coefficients (NRC) values (0.55 and 0.53, respectively at a 4 cm cavity depth). Porosity was critical for low-frequency absorption in Coconut (80.91%) and Paulownia (55.56%), while high permeability and large pore sizes favored low-frequency performance in Oak and Hackberry. Malas demonstrated balanced acoustic properties across frequencies due to its intermediate porosity and diffuse pore structure. This research highlights the novelty of correlating wood anatomy with acoustic behavior and optimizing back air cavity depth to tailor performance. The findings provide valuable insights for developing eco-friendly, wood-based acoustic materials for applications in construction, interior design, and noise mitigation solutions.

This study explores tannin and caffeine, natural compounds with inherent antifungal properties, as scalable treatments to enhance the physical and mechanical performance of oriented strand board (OSB). Unlike previous research that primarily focused on durability, this work evaluates the effects of these bio-based treatments on leaching resistance, internal bond strength (IB), bending properties, water absorption, thickness swelling, and vertical density profile (VDP). The results demonstrate significant improvements over commercially available OSB, particularly in mechanical performance. Post-leaching, both treatments exhibited superior IB, with tannin-treated panels achieving the highest IB value (0.27 MPa). The bending analysis revealed that caffeine-treated panels that were not subjected to leaching achieved the highest modulus of rupture (MOR, 62.54 MPa) and modulus of elasticity (MOE, 10.36 GPa). Both treatments retained significantly higher MOR and MOE values post-leaching compared to the industrial reference and untreated panels. Water absorption and thickness swelling were comparable among tannin-treated, caffeine-treated, and untreated panels but were significantly lower than those of the industrial reference, which was included for general benchmarking purposes alongside the laboratory-made control. VDP analysis showed caffeine-treated panels had the lowest density prior to leaching, whereas tannin-treated panels maintained the highest density after leaching. These findings highlight tannin and caffeine as effective and scalable treatments, providing a sustainable alternative as functional additives for industrial engineered wood product manufacturing.

Semi-non-destructive drilling resistance instruments have been widely adopted for timber testing and forestry for wood quality assessments. The accuracy of a drilling resistance tool for predicting wood density may be affected by needle (drill) wear, and there is limited information regarding the wear behaviour of drill bits in wood resistance drilling. It is unknown when changes in needle sharpness and diameter become critical for quantifying wood density. To measure the effect of Resi needle wear, an IML Resi PD 500 was used to obtain cross-sectional traces of Southern Pine (Pinus elliottii var. elliottii (Engelm) × Pinus caribaea var. hondurensis (Sénéclauze)) average outerwood density: 519 kg/m³ and Spotted Gum (Corymbia citriodora subsp. variegata (F. Muell.)) average outerwood density: 779 kg/m³ logs. Southern Pine was tested with feed speeds of 200 cm/min at 3500 rpm and 100 cm/min at 5000 rpm. Spotted Gum was tested with a feed speed of 70 cm/min at 5000 rpm. A new needle was used for each setting. The effect of needle wear was tested after 0, 100, 200, 300, 400, 500, and 600 m of drilling depth. There was no effect on drilling resistance values up to 600 m of drilling length with feed speed 200 cm/min and 3500 rpm settings for Southern Pine. This would result in 2000 drilling measurements of 30 cm diameter trees. With alternative setting for Southern Pine with a setting of 100 cm/min feed speed and 5000 rpm, the increase in amplitudes was not significant until 300 m of drilling, after which, at 400 m, the amplitude increased by 2% (9.8 kg/m³), and after 600 m, the amplitude increased by 3.1% (15.2 kg/m³). For the hardwood Spotted Gum, the amplitude decreased by 0.9% (2.3 kg/m³) after 100 m, and after 300 m, the amplitude decreased by 3.3% (8.2 kg/m³). After 300 m, it was not possible to drill Spotted Gum due to extensive needle wear. The study highlighted the importance of needle wear in resistance drilling, providing guidance for reliable needle use to improve measurement accuracy and wood quality assessment.

Fast-grown plantation wood species such as poplar (Populus deltoides) are widely available but inherently possess poor decay resistance and limited mechanical strength which restricts its end-use applications. This study focuses on enhancing the properties by impregnating poplar wood with polyvinyl acetate (PVAc) resin fortified with nano hexagonal boron nitride (h-BN). The vacuum-pressure impregnation process was followed for treatment and the treated samples were evaluated for fungal decay resistance against brown rot and white rot fungi, as well as density, water absorption, surface hardness, compressive strength and thermal stability. Nanoparticles distribution within the wood microstructure was analysed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) mapping. Results showed that h-BN fortification of PVAc with different concentrations further improved the properties of poplar wood. These findings demonstrate that h-BN-PVAc impregnation is a promising modification method for producing a wood with enhanced properties for indoor wood products from fast-grown species which can be promising material towards sustainable development.

The European beech (Fagus sylvatica L.) is one of the most economically and ecologically important deciduous tree species in Europe. However, there is a lack of scientific knowledge regarding quality of wood growing on former agricultural land exists in the case of European beech. Therefore, this study aimed to evaluate the wood properties of European beech growing on former agricultural land compared to standard forest stands in north-western Poland. In total 2457 specimens were tested in mechanical strength and around 1000 for dimensions of micro and macrostructural wood elements. In the case of the most important parameter – the wood density, no significant differences were found between values observed in standard forest land (0.722 g/cm³) and afforested farmland (0.701 g/cm³). Land use did not significantly influence MOR nor MOE. However, higher values for these parameters were observed on forest land. The annual ring width was significantly wider on trees that grew on former agricultural land. The high variability with significant differences was obtained within the dimensions of vessels and fibers. The presented results have confirmed that European beech species is highly suitable for former agricultural land afforestation with high-quality wood production. These findings challenge the assumption that wood on afforested agricultural land has worse quality and support its viability for industrial purposes.

The chemical wood properties characterization of biomass feedstocks is important since it determines their potential for various chemical and energy applications. Willow (Salix sp.), a short-rotation hardwood species, is an interesting feedstock for such applications. It can represent an alternative raw material for non-sustainable resources, long-rotation trees, and agricultural biological materials. This research aimed to characterize the chemical properties of different wood tissues of willow and to develop a nondestructive method for their prediction. Wood, bark, and twig samples were sampled from six willow clones (Alberta, Canada). Extractives, cellulose, hemicellulose, and lignin contents were measured in sampled tissues by destructive chemical analysis tests using TAPPI standard test methods. The surface chemistry of the samples was analyzed by near-infrared spectroscopy. Partial least squares regression models were developed for quantitatively predicting wood chemical components. The coefficients of determination (R² calibration, R² cross-validation, and R² prediction) ranged from 0.66 to 0.99 for extractives, lignin, cellulose, and hemicelluloses. Carbohydrates (glucose, xylose, arabinose, and mannose) ranged between 0.98 and 0.99, demonstrating excellent predictive capability for these components. These results confirm the applicability of the developed models to predict the chemical properties of willow biomass. Furthermore, the prediction models apply to all investigated tissues, emphasizing consistency. These results provide the possibility to characterize the chemical properties of willow biomass using easily implemented, cost-effective, nondestructive, and rapid NIR equipment.