European Journal of Wood and Wood Products最新文献

Herein, we provide an overview of intra- and interspecies variability of infrared spectra of wood in the fingerprint region (1800 –800 cm^− 1). The study is based on > 5000 FTIR spectra of 108 trees comprising 20 tree and shrub species that are common and characterize the landscape in Estonia. A larger share of spectral variability was attributed to differences between annual growth rings, with a smaller contribution from differences between individual trees and growing sites. Although all species have their characteristic spectral features that differentiate them from other species, intraspecies spectral variability strongly exceeds interspecies variability. It was found that, on average, infrared spectra is not affected by sampling direction on the growing site. 25 distinct infrared bands were detected based on first and second derivative spectra. It was possible to distinguish 16 spectral regions - every species had at least one peak in 15 of these and 100% of spectra of softwoods had a peak in the 16th region at around 1265 cm^− 1. Principal component analysis revealed that spectral variability is not driven by particular spectral bands, but rather by contributions from a broad range of wavenumbers across the entire analyzed region.

Construction wood waste (CWW) is an increasing environmental burden due to poor disposal and limited recycling. This study developed an integrated process to convert CWW into biochar, soot and ash using a top-lit updraft (TLUD) reactor. The process used CWW as both feedstock and fuel, operating at a peak temperature of 351.2 ℃ for 150 min. The resulting materials exhibited distinct physicochemical properties. FTIR analysis identified hydroxyl, carbonyl and aromatic groups across all samples. SEM revealed irregular porous particles in ash, fine agglomerated particles in soot and well-defined micro- and mesopores in biochar. XRF analysis showed that biochar and ash contained over 60 wt% calcium oxide, while soot contained 35 wt% iron oxide. BET analysis indicated that soot possessed the highest surface area of 229.057 m²/g and a pore volume of 0.151 cm³/g. The study demonstrated an efficient and sustainable approach for producing multiple carbon-based materials from construction waste. The biochar, soot and ash produced have potential applications in pollutant adsorption, catalysis, energy storage and soil improvement. This work emphasizes the value of TLUD technology in reducing construction waste and advancing circular resource management.

The utilization of multi-component environmentally friendly modifiers for wood offers an effective approach to enhancing modification efficiency and improving the overall properties of wood. In this study, a ternary modification system comprising lactic acid, taurine, and boric acid was employed to impregnate poplar wood. The effects of this modification on the physical-mechanical properties, thermal stability, and flame retardancy of the treated wood were systematically evaluated, and the underlying mechanisms were explored. Results revealed that lactic acid underwent polymerization within the wood structure, with substantial polymer accumulation observed in cell lumens. The presence of nitrogen, sulfur, and boron in the modified wood confirmed the successful incorporation of taurine and boric acid. Compared with the control, the treated wood demonstrated reduced water uptake, improved dimensional stability and thermal stability, but decreased mechanical properties. Although boric acid partially mitigated the loss in compressive strength parallel to grain, further optimization is needed to minimize these drawbacks. Flame retardancy was significantly improved, as evidenced by reduced heat release and smoke production, primarily due to the synergistic effects of taurine and boric acid. Overall, this ternary modification presents an eco-friendly and efficient method for enhancing the comprehensive performance of wood.

A survey including 3112 responses from individual end users of wood cladding, from Norway, Sweden and Germany, was conducted with questions related to their experience and preferences regarding cladding with and without coatings. Based on these results and established scientific understanding of Service Life Prediction (SLP) of wood cladding, two decision trees were provided to guide end users in selecting a suitable material to meet their expectations when planning a new cladding. This approach makes the users reflect on maintenance requirements and aesthetic changes rather than choosing a product solely based on initial aesthetic appeal.

This study examines the influence of laser power and cutting speed on the morphological characteristics of medium-density fibreboard (MDF) during CO₂ laser cutting. Experimental trials were performed on 6 mm MDF panels under systematically varied process parameters, and morphological outcomes were evaluated using scanning electron microscopy (SEM). The primary response variables included kerf width (Kw), kerf depth (Kd), cutting depth (Cd), and the heat-affected zone (HAZ). Results showed that increasing laser power enlarged Kw and intensified thermal degradation, while cutting depth peaked at mid-range power levels before declining due to beam attenuation and material accumulation. Conversely, higher cutting speeds reduced kerf expansion and minimized HAZ, yielding smoother and more precise cuts. Statistical analysis confirmed that power significantly affected Kw, Cd, and HAZ, whereas Kd was primarily sensitive to speed variations. The optimal balance was achieved at moderate power (60%) and higher cutting speeds (75–100 mm/s), which minimized carbonization while maintaining sufficient penetration. These findings provide practical guidelines for optimizing CO₂ laser cutting of MDF, contributing to efficient, precise, and sustainable manufacturing with reduced postprocessing needs.

The basic density and shrinkage properties of Scots pine wood from commercial first and second thinning-stage forests were studied in eastern Finland with a reference from final-felling forests. Linear mixed model analysis was applied, indicating statistically significant differences in basic density between stand types and forest site types, with significant effects of cambial age and height position. Additionally, the 2-level interaction terms between site type, cambial age and height position were significant. In Myrtillus type sites, the basic density was 380 kg/m³ for first-thinning wood, and 407 kg/m³ and 406 kg/m³ for second-thinning and final-felling wood, respectively. Young thinning trees showed, on average, wider growth rings (2.83 mm) compared to mature trees (2.04 mm). Density and latewood proportions increased with tree age, particularly in poor site types, whereas the growth ring width had opposite effects. Significant differences were observed in radial, tangential and volumetric shrinkage across stand types, height positions and radial positions, while the longitudinal shrinkage model indicated statistically significant differences between radial positions only. The radial shrinkage was 4.04% in the first thinnings and 4.44% in the second thinnings, while the tangential shrinkage was 6.98% and 7.16%, respectively. The substantial variation in properties, particularly in the first thinnings, likely reflected the presence of juvenile wood, stem form defects and reaction wood in the harvested material, making it less suitable for mechanical processing. The results confirmed that the properties of second-thinning wood enable its use in applications requiring higher density and allowing reasonable shrinkage.

Recycling wood and wood-based products, such as particleboards, offers a sustainable solution to wood resource constraints by generating particles for new particleboard production. This study evaluated the impact of two chipping methods—chipper-flaker and chipper-hammer mill—on the properties of particles derived from raw and melamine-faced recycled particleboards. Analytical techniques, including weight, dimensional, and geometric (shape) analyses, bulk density, pH, and resin absorption assessments, were used to characterize the particles, with results compared to industrial wood particles. Findings indicate that recycled particleboard particles exhibit higher bulk density and lower pH than industrial wood particles. The chipper-hammer mill method produced a higher weight% of coarse particles, while the chipper-flaker method generated more fine particles. Compared to industrial wood particles, recycled particleboard particles contained significantly more fine particles and fewer oversized particles. The chipping method and particleboard type influenced particle geometry (aspect, slenderness, and flatness ratios), with the chipper-flaker method yielding ratios closer to those of industrial wood particles. Conventional chipping equipment can effectively produce particles with suitable dimensions and shapes for particleboard manufacturing. Needle-shaped and rectangular particles comprised the majority of the particles (more than 50%) obtained from raw and melamine-faced particleboard. Overall, the chipper-hammer mill method excels in producing particles with optimal weight distributions, while the chipper-flaker method yields particles with superior geometric properties, enhancing their suitability for high-quality particleboard production.

This paper presents the concept and results of numerical analysis of a new type of sandwich panel with OSB facesheets and a tensegrity lattice core. The key objective of this study was to evaluate the possibility of controlling the bending stiffness of the panel by adjusting the level of prestress in the tensegrity members. The first step was the experimental determination of Young’s moduli for OSB in two perpendicular directions, which was important due to the variability of OSB properties specified in the literature. The numerical modelling was then performed using the finite element method in the ABAQUS™ environment, analysing various computational parameters, such as the type of core, the OSB thickness, the stiffness of the core, and the core-to-facesheets interaction properties. The results showed that the type of connection between the core and the OSB had the greatest impact on the controllability of the stiffness of the panel. Among others, the reduction of the number of attachment points increased the controllability of the structure. In contrast, OSB thickness and strut diameter had a negligible effect. As a result of the numerical study, a panel configuration was selected for the next step of research, which are experimental tests on the physical model.

This study provides a comprehensive analysis of the chemical composition of conifer cones from four species (pine, larch, spruce, and fir) collected from Polish forests. The aim was to examine inter-species variations in elemental composition, phenolic compounds, low molecular weight organic acids (LMWOAs), fatty acids, and sterols. The methodology involved a complex elemental analysis, determination of basic chemical composition, as well as ultra-performance liquid chromatography (UPLC) for phenolic compounds, low molecular weight organic acids (LMWOAs), and sterols. Moreover, fatty acid methyl esters (FAME) were analyzed using a gas chromatograph with a flame ionization detector (GC-FID). Results show significant species-specific differences in chemical composition of tested cones. Spruce cones had high carbon content and favorable calorific values, while fir cones were characterized by high nitrogen and low sulfur content. Holocellulose and lignin content varied across species, with pine and spruce cones containing higher holocellulose content. Elemental analysis revealed significant variations in metal concentrations, with fir cones having the highest calcium levels and spruce cones having higher levels of magnesium, copper, and zinc. Phenolic and flavonoid content also varied, with spruce cones showing the highest total phenolic contents. The analysis of LMWOAs, sterols, and fatty acids highlighted further differences in composition among species, with notable variations in shikimic, citric, and fatty acid profiles. These findings show the chemical diversity of conifer cones and their potential for varied applications.

Understanding bamboo permeability is essential for optimizing pressure-based preservative treatments and improving the durability of bamboo-based construction materials. Bamboo has a complex pore structure and contains diaphragms (nodes) along its length, which are thought to influence fluid transport. Vascular bundles (VBs) are largely continuous through internodal regions; however, at the nodes, shifts in VB orientation occur, along with the presence of horizontal bundles. In this study, air permeability and water sorptivity of bamboo nodes and internodes were measured to assess the impact of these microstructural variations on fluid transport. A reconstructed 3D model confirmed the expected structural complexity at the node, yet most VBs maintained longitudinal continuity. Fibre volume fraction between node and internode showed low variability, ranging from 33.9% to 44.5%, and VB percentage exhibited a slight reduction at the node. Although air permeability coefficients were marginally lower in node regions (k₁ = 1.00 to 5.42 × 10^− 12 m² and k₂ = 0.76 to 9.85 × 10^− 8 m), influenced by this minor reduction in VB percentage, these differences were not statistically significant compared to internodes (k₁ = 2.16 to 12.99 × 10^− 12 m² and k₂ = 2.23 to 54.53 × 10^− 8 m). Capillary water absorption and contact angle measurements were consistent between regions in the longitudinal direction and revealed much higher absorption longitudinally compared to radial and tangential directions. Overall, these findings indicate that nodes have only a minor influence on longitudinal transport, and confirm that bamboo permeability is highly anisotropic, with longitudinal coefficients that are several orders of magnitude higher than those in the radial and tangential directions.