WOOD RESEARCH Volume 71, Number 1, 2026

WOOD RESEARCH Volume 71, Number 1, 2026
KUN DU, LIJIAN YUAN, YOULI WANG, XINLIN LI, MING LI, SAIYING FANG, HAO SHI, YONGYOU CHEN, and XUANRUI GONG

DYNAMIC DETECTION THE DAMAGE AND FRACTURE PROCESS OF LOAD-BEARING WOOD USING ACOUSTIC EMISSION TECHNOLOGY

This research utilizes three-point bending experiment to simulate actual load-bearing scenarios of wood, and uses acoustic emission monitoring system to collect real-time acoustic emission signal parameters, such as ringing count, energy, amplitude, etc. Analyze the relationship between acoustic emission signals and internal damage during different loading stages, and construct an acoustic emission recognition model for damage and fracture process of elm. Research result shown that during elastic deformation and early plastic deformation stage, the activity of acoustic emission is weak, mainly due to damage and delamination at cell wall, and cell wall buckling and collapse. Entering plastic deformation stage, acoustic emission ringing count and energy significantly increase, corresponding to a large number of cell wall ruptures and microcrack initiation. Near macroscopic fracture stage, high-intensity and high-energy acoustic emission signal clusters appear, indicating rapid propagation of main crack and ultimately leading to fracture.

WOOD RESEARCH Volume 71, Number 1, 2026
Süleyman Kuştaş, ENGİN DERYA GEZER, and Sefa Durmaz

THE EFFECTS OF PRE-MICROWAVE TREATMENT ON IMPREGNATION PROPERTIES AND SOME MECHANICAL PROPERTİES OF SPRUCE WOOD TREATED WITH CCA

In this study, spruce wood speciemens were subjected to microwave (MW) pre-treatment prior to impregnation. The samples had an initial moisture content (MC) of 60% and were exposed to MW irridation in a microwave oven for 5, 5.5, and 6 min, while maintaining a constant power level of 800 W. Following the MW pre-treatment, the speciemens were impregnated with a 1.5% CCA solution using a vacuum-pressure method consisting if an initial vacuum phase of 20 min followed by a pressure stage of 30 min. Retention values and penetration depths were subsequently measured for each treatment group as well as for untreated control samples. The results indicated that MW pre-treatment significantly improved both retention and penetration performance. The retention values obtained for speciemens treated for 5, 5.5, and 6 min were 5.37, 6.04, and 6.18 kg/cm3, respectively, whereas the control samples exhibited a retention level of 3.64 kg/cm3. These findings demonstrate that MW pre-treatment enhances the impregnation efficiency of spruce wood. However, the treatment also led to reductions in certain mechanical properties, including modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS).

WOOD RESEARCH Volume 71, Number 1, 2026
YASİN KARAŞİN, BÜLENT TOPRAK, MUHAMMED ALİ AYDIN, and MEHMET ALİ ÜNLÜ

THE EFFECTS OF RAINWATER-HARVESTING V-SHAPED MICROCATCHMENTS AND PLANT-SUPPORTIVE AMENDMENTS ON SOIL MOISTURE AND EARLY ESTABLISHMENT OF FRAXINUS ANGUSTIFOLIA VAHL. UNDER SEMI-ARID MEDITERRANEAN CONDITIONS

This study assessed the effectiveness of V-shaped rainwater-harvesting micro catchments and selected plant-supportive amendments on soil moisture dynamics, survival, and early growth performance of narrow-leaved ash (Fraxinus angustifolia Vahl.) during three consecutive growing seasons (2022–2024) in western Türkiye. By the end of the first growing season, mean seedling survival was approximately 63% across treatments. However, complete mortality (100%) occurred in conventional terrace control plots by the second growing season, indicating plantation failure under this method. In contrast, V-shaped micro catchments maintained survival rates of 65% in the second year and 57% after three years. Volumetric soil water content (0–20 cm) measured during the peak drought period (July–September) was consistently higher in micro catchments than in terrace controls. In September 2024, soil moisture in the micro catchment control (C-V) reached 8.17% at the upper position and 5.88% at the lower position, compared to 3.83% and 1.53%, respectively, in terrace plots. Relative diameter increment (RDI) differed significantly among treatments (p < 0.0001), with the straw-based lignocellulosic superabsorbent polymer increasing stem diameter growth by approximately 40% compared with other micro catchment treatments. Relative height increment (RHI) was up to 2.3 times greater in micro catchment plots than in terrace controls. These findings demonstrate that integrating structural rainwater harvesting with wood- and plant-derived water-retaining amendments substantially enhances soil water availability, seedling survival, and early stem growth of F. angustifolia, thereby improving hardwood plantation establishment and resilience under semi-arid Mediterranean environments

WOOD RESEARCH Volume 71, Number 1, 2026
MONIKA STANKOVSKÁ, ANDREJ PAŽITNÝ, ŠTEFAN BOHÁČEK, ALBERT RUSS, and Elena Opálená

THE EFFECT OF FIBRILLATED CELLULOSE PREPARED FROM THE DISTILLERY CORN REFUSE ON POROSITY OF PAPER FILTERS

This study exploited the possibility of using corn distillery refuse as a cheap source of nanocellulose production. Coarse fibrillated cellulose and very fine particles were extracted by acid-alkali extraction. Two methods were compared where either acidic extraction took place before alkaline extraction or with the extraction in a reversed order. The effectiveness of removing hemicellulose and lignin was determined by IR Fourier transform spectroscopy. The optimal technique of application of fibrillated cellulose with added solutions of metal cations with antimicrobial properties on HEPA filter was selected. The optimal conditions were the alkali extraction followed by the acidic extraction and optimal application of solution of fibres and metal ions on filter paper was achieved using rod. The efficiency of filter materials was tested on a filter device with using of two model microorganisms and results showed that it is necessary to consider both the type of fibres, their optimal coating on filter paper as well as the morphology of microorganisms. The mixture of Cu, Al, Mg, Ca and Zn metal ions was sufficient for effective disinfection.

WOOD RESEARCH Volume 71, Number 1, 2026
PAVLO LYUTYY, PAVLO BEKHTA, GALYNA ORTYNSKA, and JÁN SEDLIAČIK

Evaluating the Environmental Impact of Wood-Plastic Composites Using Recycled Polyethylene

This study evaluates the environmental impact of producing wood plastic composites (WPC) using recycled polyethylene (rPE) compared to virgin polyethylene (PE). The assessment was based on a Life Cycle Assessment (LCA) framework in accordance with ISO 14040 and ISO 14044 standards, applying the Leontief model to quantify environmental performance indicators. Two key parameters were analysed: specific CO2 emissions and the amount of waste destined for landfilling. The findings indicate that the incorporation of rPE into WPC production leads to an approximate 2.7-fold reduction in total CO₂ emissions and a tenfold decrease in landfilled waste. Even when accounting for the additional 10% emissions associated with waste collection and sorting, the overall reduction remains above 60%. These findings are consistent with contemporary circular economy strategies and confirm the environmental feasibility of substituting virgin polymers with recycled feedstock.

WOOD RESEARCH Volume 71, Number 1, 2026
JATINING DIRI ABIMANYU and GANIS LUKMANDARU

The Effect of Heartwood Extraction on Kraft Pulp Properties of Acacia mangium and Acacia aulacocarpa Wood

Since heartwood parts generally contain higher levels of extractive, in this study, several extraction methods were carried out as a pre-treatment of Acacia mangium and Acacia aulacocarpa heartwood sawdust, followed by kraft pulping in a micro digester. After extraction, pulp properties from the two species were significantly different. Polar solvent extraction effectively increased pulp yield and decreased kappa number levels, while the successive extraction had less impact. Pulp kappa number significantly increased after n-hexane extraction. Compared to the control samples, pulp brightness of A. aulacocarpa wood for single solvent and successive extraction increased sharply. The overall pulp hexuronic acid content significantly decreased after extraction. Successive extraction led to significantly lower pulp viscosity compared to a single solvent extraction. In general, heartwood extraction significantly increased the pH values of A. aulacocarpa black liquor. Considering pulp properties, this study recommends hot-water extraction for A. mangium and successive extraction (n-hexane and methanol) for A. aulacocarpa

WOOD RESEARCH Volume 71, Number 1, 2026
RIZKI ARISANDI, AISHAH AGUSTIAN, DWI LARASWATI, IKHNU PAWESTRI WARDANI, MASAGUS MUHAMMAD PRIMA PUTRA, GANIS LUKMANDARU, Andrian Fernandes, AULIA NUR LAKSMITA, DEBY MIPA SALAM, and RIZKI MAHARANI

The Extractive Analysis of Resins from Dipterocarpus verrucosus Fowx. E and Araucaria cunninghamii Aiton ex D. Don

The extractive analysis of D. verrucosus and A. cunninghamii identified key chemical markers in their resins. GC-MS analysis showed that sesquiterpenes, such as β-spathulenol and β-elemene were dominant in the neutral fractions of the two species. Furthermore, diterpenes, especially thunbergol, were found to be dominant in D. verrucosus while absent in A. cunninghamii. In addition, the acidic fractions were primarily composed of fatty and resin acids, mainly palmitic acid (D. verrucosus) and sandaracopimaric acid (A. cunninghamii). The study concludes that the specific combination of sesquiterpenes, fatty acids, and resin acids serves as a chemical fingerprint for the two species.

WOOD RESEARCH Volume 71, Number 1, 2026
TIANWEI ZHANG, MINGZE BAI, HAO LIU, ZIDONG GUO, ZHIXIN TANG, HAO CHANG, and XIAORUI ZHANG

Aging of Wooden Components in Ancient Timber Structures. Fire Risk and Smoke-Heat Hazards

Based on the aging characteristics of wooden components, this study adopted artificial accelerated aging and fire propagation apparatus (FPA) to examine how aging affects the combustion behaviour, fire risk, and smoke-heat hazards of pine wood commonly used in ancient structures. Wood specimens with dimensions (100×100×10 mm and 300×100×10 mm) matching fire performance tests were prepared, and artificial accelerated photoaging treatment was conducted to obtain aged samples with 0, 60 and 120 aging cycles in accordance with the accelerated aging test protocol for wood materials. The results indicate that pine combustion involves three distinct thermal stages: pyrolysis, smouldering, and flaming, with critical high-risk transition points identified. Aging intensified fire risk and related hazards across all stages, particularly accelerating flame spread on vertical components.

WOOD RESEARCH Volume 71, Number 1, 2026
UMESH LAMICHHANE, TASFIA HASSAN, AMIR MOOTAB SAEI, FATEMEH REZAEI, MOSTAFA MOHAMMAD ABADI, YUNSANG KIM, ALI DORIEH, and SAURO BIANCHI

The Effect of Hardeners on the Dry and Wet Bondline Strength of Quebracho Tannin Resin in Three-Layer Plywood

This study investigates the tensile shear strength of maple plywood bond lines bonded with quebracho tannin adhesive, modified using different hardeners: hexamine, paraformaldehyde, and methylene diphenyl diisocyanate. Adhesives were prepared by dispersing tannin powder in water, followed by the incorporation of each hardener, and applied to three-layer veneer panels cured under hot pressing. Bond line performance was evaluated under dry and wet conditions using tensile shear tests, with wet testing incorporating an accelerated cyclic-boil aging protocol. The results revealed that paraformaldehyde-modified tannin adhesives achieved the highest dry strength, 3.5 MPa, significantly exceeding the performance of both other tannin-based systems and synthetic adhesives. In contrast, under wet conditions, no significant differences were observed among tannin-based and synthetic adhesives, underscoring the strong influence of moisture on performance

WOOD RESEARCH Volume 71, Number 1, 2026
CARLOS ALBERTO URTIS-FLORES, MAURO MANUEL MARTÍNEZ-PACHECO, REBECA DEL CARMEN PEÑA-MONTES, and Crisanto Velázquez-Becerra

The Identification of Xylophagous Fungi and Evaluation of Mechanical Damage in Preserved Wood

In this study, seven xylophagous fungi (Trametes; Trichoderma A1; Trichoderma A2; Aspergillus; Paecilomyces; Coniochaeta; Gloeophyllum) were exposed to wood preserved with CCA salts, boric acid, and a polyphenolic extract (ExPol). The results showed a prevalence of xylophagous fungi that affects the use of wood. Changes in physical parameters such as mass are accompanied by changes in mechanical properties; variation in weight losses went from 12.69-20.42 %, 6.13-19.70 % and 6.38-23.68% for CCA, H3BO3 and ExPol respectively. In conclusion, variations in response to the preservatives were shown for each microorganism due the fact that metabolism is not the same because they use the substrate components or polymers in different ways for growth, being Expol the best option to inhibit Trametes, Trichoderma A2 and Aspergillus, there’s not much difference between CCA and H3BO3 for the control of the rest of the organisms but both are better alternative than ExPol to inhibit their growth.

WOOD RESEARCH Volume 71, Number 1, 2026
TING LIU, YAOXING SUN, HONGGANG ZHAO, Huachun Qi, and Jiuyin Pang

Core-Shell Ag-TiO2@EVA Preparation and Its Application in Wood Anti-Fungal, Anti-Mold and Anti-Decay Research

Using silver-loaded nano-TiO2 (Ag-TiO2) and ethylene-vinyl acetate (EVA) emulsion as raw materials, a core-shell structured Ag-TiO2@EVA composite material was synthesized to impart antimicrobial, mold-proof, and decay-resistant properties to wood. The study investigated the composite material’s efficacy in controlling wood-staining fungi and molds, as well as its decay resistance and antifungal performance. The results showed that when the film thickness was between 0.12 to 0.15 mm with an Ag-TiO2 content of 20% or more, or when the film thickness was between 0.21 to 0.24 mm with an Ag-TiO2 content of 15% or more, the control efficacy against Botryodiplodia theobromae and Aspergillus niger reached 100%, and the decay resistance grade against Poria placenta was level I. For samples with 10% Ag-TiO2 content, the inhibition zone diameters against A. niger and B. theobromae were both greater than 10 mm, while samples with 15% and 20% Ag-TiO2 content exhibited inhibition zones larger than 20 mm, indicating strong antimicrobial effects.

WOOD RESEARCH Volume 71, Number 1, 2026
GÁBOR ORBÁN, FANNI SZOKE, LASZLO TOLVAJ, and ANTAL KÁNNÁR

The Comparison of the Effect of UV Irradiation and the Combined Effect of UV Irradiation and Water Leaching on the Color of Grey Poplar

A series of grey poplar (Populus x canescens) samples was irradiated by strong ultraviolet (UV) light emitter mercury lamp, while another series of specimens were treated with the combination of UV irradiation and water leaching. The total duration of UV irradiation for both series of specimens was 20 days. The colour parameters (CIE L*, a*, b*) were measured and evaluated after both UV irradiation and water leaching. Due to the 20 days of UV irradiation, the initial redness value of sapwood increased 2.69 times, while leaching reduced this factor to 1.77. In case of heartwood, the initial redness value increased 1.34-fold due to the 20-day UV exposure, while the leaching reduced this factor to 1.14. These multiplier values are 2.07 and 1.44 for the yellowness of sapwood, as well as 1.57 and 1.29 for the yellowness of heartwood. The leaching partly removed the yellow and red chromophore molecules generated by the UV irradiation. The samples were slightly lighter after water leaching

WOOD RESEARCH Volume 71, Number 1, 2026
QINYI GU, HONGHAI LIU, and TAO LI

The Effect of Surface-Densification and Superheated Steam Modification on Impact Resistance and Surface Properties of Rubberwood

Employing rapid surface loading (160°C, 10 s) during hot pressing can elevate the peak density of the wood’s surface, thus augmenting its rigidity and impact resistance capabilities. Subsequently treatment with superheated steam (190°C, 1.5 h). The findings of the study indicate that the impact resistance of the modified rubberwood increased by 29.2% compared to the untreated control samples. Remarkably, it even surpassed that of Fraxinus mandshurica, a premium quality hard wood species. Moreover, the wood’s colour has transformed into a purple brown hue, endowing it with a more aesthetically pleasing and refined appearance. Additionally, the paint film on the wood’s surface exhibits strong adhesion, meeting the requirements of Grade 1 as stipulated by the national standard. This combined modification method effectively enhances the overall performance of rubberwood.

WOOD RESEARCH Volume 71, Number 1, 2026
ABDÜLHALIM BEŞPARMAK and HASAN ÖZGÜR IMIRZI

Structural Integrity-in Unconstrained Densification of Partially Delignified Poplar

In this study, the effects of a chemical-mechanical modification system on low-density poplar (Populus tremula L.) wood were investigated without external confinement. Wood samples were initially treated with an alkali-sulphite solution (2.5 M NaOH, 0.4 M Na₂SO₃ for 7 h) to induce partial delignification, after which they were densified at 100°C under 5 MPa pressure. Following this process, a significant increase in density to 1.22 g/cm³ (+172.6%) was recorded. Mechanical evaluations indicated substantial enhancements; specifically, Brinell hardness, bending strength (MOR), and modulus of elasticity (MOE) were improved by 346.3%, 67.4%, and 78.3%, respectively, confirming the successful consolidation of the cellulose network. However, a trade-off was revealed by microscopic analysis, and two distinct failure mechanisms were identified. First, large cracks (~150 µm) were formed in the core due to diffusion limitations that prevented full chemical penetration. Second, widespread micro-cracks (~4 µm) were triggered in the densified shell by the Poisson effect due to the lack of lateral confinement. These results suggest that while hardness is significantly improved by unconstrained densification, compressive performance is compromised by the resulting defects. While the modification was intentionally applied to 35 mm thick lumber to reveal diffusion limitations and Poisson-induced defects under unconstrained conditions, small, defect-free specimens were subsequently selected for mechanical testing to isolate and characterize the intrinsic properties of the successfully modified regions near the surface.

Category: WOOD RESEARCH Volume 71, Number 1, 2026