This study investigated modifying casein adhesives to improve their moisture resistance and elasticity for use in the wood industry. Six different formulations were tested, including pure casein adhesive, polyvinyl acetate (PVAc) adhesive, and mixtures of the two, as well as modifications involving abietic acid, borax, and diethyl phthalate. While the modified casein adhesives met the minimum requirements according to DIN EN 205, they did not match the performance of the unmodified casein adhesive. Although the modified adhesives performed worse than the unmodified variants, they still demonstrate the potential for sustainable use of non-marketable milk as a source of raw materials.
The tree-of-heaven (Ailanthus altissima (Mill.) Swingle) is one of the most aggressive arboreal invaders, threatening forest health and biodiversity across five continents. Given its rapid spread, severe ecological impact, and management difficulty, this paper (i) synthesises current knowledge of ecological factors driving its invasion in forest settings, (ii) critically evaluates available control methods, and (iii) proposes an integrated, evidence-based management framework suitable for forest ecosystems. Prevention strategies, such as legislation, vigilant monitoring, and the rapid removal of female trees, are essential first-line defences. For control, systemic herbicides applied via foliar sprays, basal bark, cut-stump, or stem injection methods provide the most effective long-term suppression. In contrast, mechanical or physical treatments alone often result in vigorous resprouting. Biological control agents show potential but remain purely experimental. However, the absence of approved biological agents and the limited availability of long-term cost-effectiveness data currently constrain management planning and large-scale implementation in forest ecosystems. This review presents a decision matrix that links control options to tree ontogenetic stages and site conditions, highlighting research needs that balance effectiveness, costs, and ecological safety. Overall, this synthesis offers a clear, evidence-based toolkit for managers and policymakers managing A. altissima in forest ecosystems.
DWC (Deep Wood Classifier) is a hybrid method that aims to achieve high accuracy and efficiency in wood species classification by combining deep learning and classical machine learning algorithms. In this method, convolutional neural network (CNN) models such as EfficientNetV2B3, Xception, and InceptionResNetV2 are optimised and trained to classify wood species. The accuracy rate is further improved when the features extracted from these deep learning models are classified with classical machine learning algorithms. The combination of EfficientNetV2B3 and SVC provides fast and effective classification with 99.56% accuracy, while Xception and Logistic Regression achieved the highest success with 99.69% accuracy. The DWC method exhibited excellent results in confusion matrix and ROC curve analyses, providing higher accuracy and more efficient training processes compared to existing methods in the literature. The combination of deep learning and classical machine learning algorithms has made DWC stand out with its high accuracy rates and fast training times. This hybrid approach offers a significant innovation in wood species classification, demonstrating superior performance compared to other methods in the field.
This study concerned the possibility of enhancing the outdoor performance and thermal properties of wood-plastic composites (WPCs) by incorporating nanoparticles (NPs). Titanium dioxide (TiO2) NPs were selected, being one of the most commonly used types, and were added to the matrix in concentrations up to 10%. Their addition improved the mechanical properties of WPCs due to the strong interaction between TiO2 and the composite components. Furthermore, the good reflectivity properties of TiO2 improved the surface color stability of WPCs. Even under intensive UV light exposure, the surface color changes in WPCs containing TiO2 were moderate compared with the control samples. Microscopic analysis indicated that TiO2 NPs significantly reduced crack formation. Although surface erosion was not completely inhibited, it was reduced. The condensation cycle of weathering weakened the bonds between the wood and polymer, leading to mechanical losses. Scanning electron microscopy (SEM) images revealed micro-cracks, which explained the decreased values obtained for the mechanical properties of reinforced WPCs. However, the decrease was limited to 0.46% for composites containing 5% TiO2. The TiO2 NPs also acted as a thermal barrier, retarding thermal degradation, which occurred more moderately than in the controls. Additionally, the fire performance of reinforced WPCs was enhanced by TiO2 NPs, which improved char formation and increased the limit oxygen index (LOI) values to 25.9% O2.
The natural frequency of a building is one of the main parameters affecting the dynamic and acoustic properties of the building. This study investigates the influence of two timber ceiling technologies-KVH timber and the Steico wall system-on the dynamic and acoustic properties of prefabricated timber-frame buildings. KVH is a kiln-dried, finger-jointed solid structural timber widely used in load-bearing applications, whereas the Steico wall system is a prefabricated lightweight timber panel designed for sustainable construction. Also, this paper aims to study the effect of the presence of an additional story on the dynamic and acoustic properties of timber buildings. Three different timber buildings have been taken into account. The first one is a two-story building with a KVH layer, the second one is a one-story building with a Steico wall, and the third one is a one-story building with a KVH layer. Measured fundamental natural frequencies were 42.63 Hz, 26.81 Hz, and 21.39 Hz, respectively, demonstrating clear quantitative differences between the systems. Statistical indicators, including mean values, standard deviation, and coefficients of variation (below 15%), confirm acceptable repeatability. The stiffness of those buildings has been evaluated as well. It was concluded from this study that the ceilings composed of the KVH layer have better acoustic properties than the ceilings composed of the Steico wall. Also, it was concluded that the presence of an additional story worsens the acoustic properties of the ceiling and increases the stiffness of the building, affecting the dynamic properties of the timber building.
Pineapple (Ananas comosus L.), a perennial herb belonging to the Bromeliaceae family, is one of the most important tropical and subtropical fruits worldwide, ranking third in global tropical fruit production after banana and citrus and contributing nearly 20% of total tropical fruit output. It is consumed fresh and widely processed into canned slices, jellies, pickles, jams, squashes, juice concentrates, and flavoring essences, and is well regarded for its rich nutritional profile, including minerals, vitamins, dietary fiber, and pronounced antioxidant activity. Despite this extensive utilization, processing residues—particularly pineapple peel (PP)—remain comparatively underexploited. Historically, research on pineapple waste has largely emphasized two major directions: the extraction of bromelain and the generation of value-added products such as ethanol, phenolic antioxidants, heavy metal adsorbents, organic acids, biogas, and fibers, typically through cost-effective approaches like fermentation and drying. This paper focuses explicitly on PP, considering it not merely as agro-industrial biomass but as a promising engineering material. It offers a comprehensive account of PP generation, its detailed physicochemical composition, and the principal extraction techniques used to recover high-value compounds, while examining how different pre-treatment strategies enhance extraction efficiency. Furthermore, the paper highlights the potential applications of PP-derived extracts and fractions in both biomedical and engineering sectors, underscoring their relevance beyond conventional waste disposal or low-value by-product utilization. Ultimately, the study aims to reframe PP as a versatile, high-potential engineering feedstock capable of contributing meaningfully to sustainable material development and supporting a more circular, resource-efficient bioeconomy.
The study examines the performance of various deep learning approaches in identifying tropical wood species from macroscopic images. In the study, non-optimised, transfer learning applied, and optimised convolutional neural network (CNN) models were compared. The obtained results show that the optimised models, featuring EfficientNetV2B3, exhibit remarkably high accuracy and performance in tropical wood classification. In the evaluation of the optimised models, EfficientNetV2B3 achieved the highest performance with 99.01% accuracy, 99.02% precision, 99.01% recall, and F1-score values. Xception and MobileNetV2 also achieved notable results with 98.64% and 98.02% accuracy, respectively. These results reveal that the optimised models, especially EfficientNetV2B3, are highly effective for tropical wood classification. Compared with the literature, this study has made significant progress in the field of wood species classification, especially by achieving an accuracy rate of 99.01% with the EfficientNetV2B3 model. These results demonstrate how effective deep learning models can be on complex classification problems, especially when they are optimised. In conclusion, this study recommends the use of the EfficientNetV2B3 model for the classification of tropical wood species and emphasises that this model serves as a benchmark in this field with its high accuracy, precision, and generalisation ability. In the future, it is suggested to further develop this method by testing it on different datasets and classification problems. This work provides a significant contribution to the fields of wood science and automatic species recognition.
It is known that blue stain causes a loss of price value for Scots pine wood in the wood trade due to the visual defects it creates. In this study, color parameters [red color tone (a*), lightness (L*) value, yellow (b*) color tone, tone angle (h degrees) value, and chroma (C*) value], whiteness index (WI*) values, and glossiness measurements [at angles of 20 degrees, 60 degrees, and 85 degrees] were compared in Scots pine (Pinus sylvestris L.) wood with normal and blue rot conditions. According to the color parameters obtained, it was determined that the L* value decreased by 11.43%, a* by 79.95%, b* by 28.86%, and C* by 32.75%, while the h degrees value increased by 17.74%. With the blue coloration, decreases were observed in the 20 degrees glossiness values measured in the & boxV; and 1 directions, while increases were observed in the 60 degrees and 85 degrees glossiness values measured in the & boxV; and 1 directions. With the blue coloration, decreases of 12.86% in the 1 direction and 29.87% in the & boxV; direction in the WI* values were observed. According to these results, it was determined that the wood material with the blue coloration disease had a darker color.
In this study, the usability of artificial antioxidants, nano-oxides, and generally regarded as safe (GRAS) compounds in the wood preservation industry was investigated. For this purpose, some physical, biological, and mechanical properties and surface chemistry analysis of Scots pine wood impregnated with 14 different compounds selected from these three different groups was performed. The physical changes in the impregnated samples were evaluated based on water absorption rate and water repellency. In addition, combustion behavior and color changes were examined to assess fire and surface optical/color properties, respectively. To investigate the biological properties of the impregnated wood samples, a fungal decay resistance test was applied using Coniophera puteana fungus. To reveal the changes in the mechanical properties of wood compression strength parallel to grain test was applied. The limit oxygen index (LOI) test was conducted to investigate the combustion properties of the impregnated wood samples. To interpret the interaction of the impregnated samples with wood, surface chemistry analysis was carried out, and a Fourier Transform Infrared Spectroscopy (FTIR) test was performed. Scanning electron microscopy (SEM) analyses were performed to observe the distribution of impregnated samples in the wood. After all these tests, it can be concluded that the tested artificial antioxidants, nano-oxides, and GRAS compounds can be used as impregnation materials. Especially, nano-oxides exhibited good performance in many aspects. Therefore, it is recommended to examine nano-oxides more closely with other experimental variations. As a result, such multifunctional compounds could be promising protection alternatives with environmentally friendly characteristics to highly toxic biocides.
In this study, samples of oriental beech (Fagus orientalis L.), hornbeam (Carpinus betulus L.), and alder (Alnus glutinosa L.) wood, which are widely used in furniture production and other sectors of the woodworking industry, were comparatively examined under different climatic conditions, and their interchangeability was investigated. For this purpose, test specimens prepared from the three wood species were subjected to tests at 20 degrees C/65%, 40 degrees C/35%, and 10 degrees C/50% temperature and relative humidity conditions, and their physical and mechanical properties were determined. As a result, among the diffuse-porous wood species examined, the density of hornbeam wood was found to be 0.76 g/cm3, while that of beech wood was 0.73 g/cm3. The bending strength was determined as 129.4 N/mm2 for hornbeam wood, with the closest value observed in beech wood at 121.2 N/mm2. Similarly, the modulus of elasticity in bending of hornbeam and beech wood was found to be at comparable levels. However, the highest impact strength was measured in beech wood at 82.4 kJ/m2, while the lowest was in hornbeam wood at 56.6 kJ/m2, with alder wood exhibiting an intermediate value of 67.3 kJ/m2. When the hardness values of the wood species were examined, it was observed that beech wood (29.2 N/mm2) and alder wood (25.1 N/mm2) exhibited similar hardness resistance. Therefore, it can be concluded that hornbeam and beech wood can be used interchangeably for load-bearing applications, whereas for applications requiring hardness and impact strength, beech and alder wood species may be preferred as substitutes for one another. Thus, when the use of one of these three wood species is required, sourcing based on availability and ease of transportation may provide an economic advantage.
The use of natural fibre-reinforced polymer (NFRP) composites has been increasing constantly due to their significant advantages in civil engineering and in the automotive and aerospace industries, among others. Fibres such as jute are ecological, renewable, and completely or partially biodegradable. This allows them to contribute to the development of new high-performance polymer materials with excellent strength properties (e.g., tensile strength, flexural behaviour, fracture toughness, and fracture resistance). This paper discusses the results of experimental tests of the performance in bending and shear of glued beams reinforced with prestressed jute fibre rods and fabrics. Twenty-four technical-scale wooden beams were used for four-point bending shear tests, each beam having a different reinforcement percentage. The study found that high performance was achieved with FRP jute reinforcement, with a single layer increasing load-bearing capacity by approximately 13% and stiffness by approximately 12%. A double layer provided even greater performance, with increases of approximately 27% and 14%, respectively. Moreover, in the case of unreinforced beams at mid-span the deflection under long-term load was 28%, while it was approximately 35% for a mid-span beam made of solid laminated timber with single jute reinforcement, and approximately 36% for a double jute reinforcement. In the numerical analysis, the differences between the experimental and numerical models were approximately 5%, representing satisfactory results for design prediction.
This article presents a comparative analysis of the requirements for overseeing recycled wood used as raw material in the production of wood-based panels. It covers three key normative documents: the German AltholzV regulation (2002/2022), Italian national standard UNI 11951 (2024), and IKEA corporate specification IOS-MAT-0010 (2025). Distinctions were observed in the regulatory status and functional scope of these documents. AltholzV constitutes a legally mandated regulatory instrument, whereas UNI 11951 represents a voluntary industry standard, and IOS-MAT-0010 functions as a corporation-specific supply chain specification. The AltholzV framework establishes a classification system for waste wood based on contaminant profiles, thereby determining appropriate recovery pathways-specifically distinguishing between material recycling and energy recovery applications. In contrast, UNI 11951 outlines the technical requirements and operational procedures governing the use of pre-consumer and post-consumer recovered wood in the manufacture of wood-based panel products. IOS-MAT-0010 is designed to ensure chemical safety and regulatory compliance by controlling potentially hazardous substances, including heavy metals, biocides, flame retardants, and formaldehyde emissions in finished products. These regulations are not harmonized. The results indicate that to operate effectively in diverse markets, manufacturers must implement an integrated oversight system that combines the most stringent requirements of legal regulations (AltholzV), industry standards (UNI 11951), and corporate specifications (IOS-MAT-0010). This approach helps avoid sanctions, customer loss, and additional costs. The study's conclusions also highlight the need to harmonize AltholzV, UNI 11951, and IOS-MAT-0010 to simplify the procedures and reduce the administrative burden for manufacturers.
This study investigates the use of shredded Pinus sylvestris (Scots pine) cones as a partial replacement for industrial wood chips in the surface layers of three-layer particleboards. Boards were manufactured with a target density of 700 kg/m3 and a thickness of 16 mm, bonded with urea-formaldehyde adhesive. Scots pine cone particles were introduced into the surface layers at substitution levels of 10-60% relative to wood chips, while the core layer consisted entirely of industrial chips. The preparation process included drying, milling, classification of cone particles, and hot pressing under controlled temperature and pressure conditions. Standardized tests according to EN requirements were conducted to determine mechanical properties, complemented by scanning electron microscopy (SEM) for structural evaluation. The results showed that all boards met EN 312 flexural strength requirements, with up to 15% improvement in surface screw pull-out resistance at the highest cone content. SEM analysis revealed that pine cone particles have a complex, entangled fibrous structure, unlike conventional chips, enhancing mechanical interlocking with the resin. This improved interfacial bonding contributes to better stress transfer and reduced porosity in the outer layers. Additionally, boards gained unique aesthetic features from the natural coloration of cones. These findings demonstrate that underutilized biomass can be successfully applied in sustainable, structurally sound, and visually appealing wood-based panels.
Deadwood landings were established in three locations in Poland-two for the storage of pine timber, and one for spruce timber. Three measuring baskets were placed on each landing yard. In each basket, rollers were arranged in three test layers. In each test layer, 7 rollers were arranged. Each test roller was cut in the middle of its length, and a disc was taken from its inner part for further analysis. Each disc was photographed. Photographs obtained during successive trials were analyzed with the Multi Scan program. During the 54 months of research, 12 measurements were performed. On the faces of pine and spruce rollers, an increase in the area occupied by blue stain was initially observed, and then the area of blue stain began to decrease. A similar trend was also observed in the case of hard rot. In the case of soft rot, a large variability was observed in the areas in the subsequent months of the study. However, in the final stage of the study, an increase in the area of the faces occupied by soft rot was observed. As a result of the research it was found, it can be stated that the process of pine wood decomposition occurs, but it is very slow. In the case of spruce wood, the decomposition process is more intense and is particularly visible after 18 months of storage.
High-density fiberboard (HDF) has been utilized in various forest-based industries for centuries. This study investigated the effects of different adhesive ratios on the properties of HDF through a series of tests. The panels, designed in particular for this examine, had been produced in a laboratory putting the usage of a combination of 70% fir (Abies nordmanniana subsp. bornmulleriana) and 30% beech (Fagus orientalis L.) fibers sourced from the western Black Sea area of Turkey. Two adhesive levels were tested: 10.73% for Panel - I and 11.30% for Panel - , both calculated based on dry fiber weight. We assessed several physical and mechanical properties, including density, modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), hardness, water absorption, and through-thickness swell, in accordance with standard testing methods. The results indicated that both adhesive levels produced panels meeting the general performance requirements for HDF. Panel II, which contained slightly more adhesive, demonstrated marginally better performance in specific strength and dimensional stability tests. Overall, the findings suggest that optimizing adhesive usage in industrial HDF production can help establish a balance between the performance requirements of the boards and cost-effectiveness in production.
As a cornerstone structural material in Chinese architectural heritage, understanding the long-term durability of Chinese fir (Cunninghamia lanceolata) is critical for its preservation. This study comparatively investigates the degradation of Chinese fir under three accelerated aging protocols simulating key environmental threats: ultraviolet (UV) weathering, thermal-humidity cycling, and salt fog. The results revealed distinct degradation mechanisms with significant implications for heritage diagnostics. Salt fog exposure induced the most severe degradation, causing a 63.9% loss in bending strength through comprehensive chemical attacks. UV weathering led to significant surface photodegradation and microcracking, while thermal-humidity cycling caused a 46.5% reduction in bending strength, primarily due to physical stresses. Crucially, a strong, universal correlation was established between cellulose crystallinity (CrI) and the mechanical properties (tensile, R = 0.874; compressive, R = 0.902; bending, R = 0.941) across all aging conditions. This identifies CrI as a robust and minimally invasive indicator for assessing the mechanical integrity of historic timbers. Furthermore, the degradation kinetics under each stressor followed highly predictable linear trends (R² > 0.89), providing a quantitative basis for developing targeted conservation strategies and more accurate service life prediction models for timber heritage structures.
The first part of the study (Natural Durability of Some Wood Species in Ground Contact at Four Sites in Turkey Part 1: The Physical Properties) was published in the 67th volume of Drewno. This study involved the examination of heartwood, sapwood, and CCB (Copper Chromium Boron) impregnated sapwood samples from various tree species including Scots pine (Pinus sylvestris L), Caucasian spruce (Picea orientalis (L.) Peterm), European beech (Fagus orientalis L.) and common alder (Alnus glutinosa subsp. barbata), which had 20x20x300 mm dimensions. These samples were subjected to soil contact, specifically in hazard class 4 conditions as defined by EN 252 (2014), for a duration of 3 years. The study was conducted in four different provinces of Turkey, namely Trabzon, Muğla, Çanakkale, and Elazığ, each characterized by distinct climatic conditions. Bending strength, modulus of elasticity and compression strength of the samples collected back from test sites were examined. The highest bending strength, modulus of elasticity and the highest compression strength were observed in Elazığ (dry climate). In Çanakkale, Muğla and Trabzon (humid climate), relatively lower values were recorded. In terms of climate type, it can be said that Scots pine and Caucasian spruce wood samples have higher resistance than the European beech and common alder samples. Especially the heartwood of coniferous has been found to be more durable than the sapwood. In addition, no deformation was observed in any of the impregnated wood samples. The durability of all treated wood samples met the minimum requirements for (soil/outdoor/contact etc.).
The growing demand for wood as a raw material, coupled with the impacts of climate change on coniferous forests, necessitates research into underutilized wood species and potential hardwood alternatives. By integrating material characterisation with computational analysis, this research aims to bridge the gap between resource availability and structural performance. This study focuses on developing a numerical model to simulate the mechanical behavior of softwood, hardwood, and hybrid cross-laminated timbers (CLT) under bending loads within the linear elastic range. The research methodology involved finite element analysis to simulate four-point bending tests on hybrid CLT panels using the open-source FEM solver Code_Aster. Material properties were determined based on Non-Destructive Test (NDT) measurements and literature data. The developed finite element model successfully simulated CLT’s response under four-point bending conditions, demonstrating its potential for virtual prototyping of various underutilized wood species in CLT applications. The numerical model showed acceptable agreement with experimental results. The relative error varies between 1.30% to 17.37% in the results based on the NDT measurements. The results derived on literature values show higher variation. This computational approach provides a valuable tool for evaluating alternative wood species in engineered wood products.
The paper investigates an assessment of mechanical strength in relation to dynamic and static MOE of Antrocaryon micraster stemwood from the semi-deciduous ecological zone in Ghana. The objective was to assess the strength variation of Antrocaryon micraster stemwood along the axial direction, using destructive and non-destructive methods. Antrocaryon micraster stemwood that was divided into bottom, middle and top positions were prepared for the study. The results reveal that the stemwood bottom position obtained maximum density (530.43 kg/m³) representing 10% and 16.02% higher when compared to other corresponding positions (middle and top) respectively. For stemwood along the axial direction, the static MOE mean values were 18.54%, 22.82%, and 27.48% more than the dynamic MOE obtained in the bottom, middle and top positions, respectively. At 1% and 5% levels of significance, the position of the stemwood along the tree height has a significant effect on dynamic MOE and static MOE. Statistical evaluation with regression and Pearson correlation also indicates positive relationship with the variability of 50.4% and 71%, respectively. In a whole, the mechanical behaviour of the Antrocaryon micraster stemwood, especially the bottom position along the axial plane is considered wealthy to be selected for furniture applications.
In this study, a total of 60 chestnut (Castanea sativa Mill.) wood samples were exposed to soil contact conditions for a period of three years in accordance with the EN252 standard. The tests were conducted in four provinces of Türkiye-Trabzon, Muğla, Çanakkale, and Elazığ-representing the Blacksea, Mediterranean, mixed, and terrestrial climate zones, respectively, in order to assess the natural durability of the wood under different environmental conditions. Climatic indices, soil characteristics, visual decay, mass loss, density, bending strength, modulus of elasticity, compressive strength, and color change were investigated. Among the four locations, the lowest average visual decay rating was observed in chestnut wood Elazığ (1.0), while the highest was recorded in this species of wood in Çanakkale (3.6). Similarly, the greatest weight loss occurred tested wood in Çanakkale, reaching 35.96%, whereas wood in Elazığ exhibited the least mass loss at 4.71%. Regarding density, wood in Elazığ presented the highest value at 0.54 g/cm³, whereas wood in Çanakkale showed the lowest at 0.39 g/cm³. The highest bending strength was wood in Elazığ at 71.73 N/mm2, the lowest was wood in Çanakkale at 38.28 N/mm2. The highest elastic modulus was wood in Elazığ at 5965.89 N/mm2, the lowest was wood in Çanakkale at 3855.42 N/mm². The highest compressive strength parallel to fibers (underground and aboveground) was wood in Elazığ at 48.25 N/mm² and 50.87 N/mm², respectively; the lowest was wood in Çanakkale, 13.51 N/mm² and 40.59 N/mm², respectively. The most significant color change was observed in the chestnut wood in Trabzon.
