Articles – Page 2 – Wood Research

WOOD RESEARCH Volume 71, Number 2, 2026
RICARDO DE CARVALHO BITTENCOURT, STÉPHANI CAROLINE DE LANA ARÊDES, GABRIEL DE CASTRO BRUMANO, ISABELLE LUISA DA SILVA FERREIRA, GABRIEL MACHADO AUGUSTO, and MARCELO MOREIRA DA COSTA

The Production of Bleached Hardwood Kraft Market Pulp Utilizing Corymbia spp. Wood

Forestry innovation in wood quality seeks to enhance pulp and paper industry performance, particularly in the production of bleached hardwood kraft pulp (BHKP), by reducing operating costs through lower specific wood consumption (SWC) and decreased bleaching chemical demand. In this study, 16 clones of Eucalyptus spp. and Corymbia spp., developed by Aperam BioEnergia Co., were initially evaluated and ranked, with the top six selected for further analysis. The objective was to assess their performance during the bleaching stage of kraft pulping. Pulp quality was determined based on intrinsic viscosity, brightness, and chemical composition. The hybrid ID 3 (Corymbia citriodora × Corymbia torelliana) showed superior performance, achieving 93.0% ISO brightness, 54.8% oxygen delignification efficiency, an S/G ratio of 3.62, and xylan content of 16.4%. It also presented the highest intrinsic viscosity (912.5 dm³/kg), indicating its strong potential for industrial application

WOOD RESEARCH Volume 71, Number 2, 2026
MONIKA STANKOVSKÁ, ALBERT RUSS, ANDREJ PAŽITNÝ, ŠTEFAN BOHÁČEK, Elena Opálená, and JURAJ KRIŠTA

THE COMPARISON OF METHODS FOR THE PREPARATION OF FIBRILLATED CELLULOSE FROMDISTILLERY CORN REFUSE USING STEAM EXPLOSION

This study proposes a novel approach involving steam explosion for the production of fibrillated cellulose using distillery refuse as a by-product of bioethanol production. The effect of the steam explosion with or without additional pre-treatment or post-treatment of distillery refuse on lignin and hemicellulose degradation was studied by infrared spectroscopy and fibre length distribution. Partial decomposition of hemicellulose was observed after the use of steam explosion combined with acid-alkali pre-treatment. The process was less effective by using steam explosion, followed by oxidation and bleaching, however, it showed better results in comparison with steam explosion followed by single oxidation. Steam explosion combined with acid-alkali pre-treatment or with oxidation combined with bleaching effectively decomposed lignin. Average arithmetic fibre length after treatment by single steam explosion rapidly decreased but additional treatments no longer caused its further decline. The application of fibrillated cellulose obtained by a single steam explosion on the filter decreased the average pore size. Anchoring of metal salts combined with fibrillated fibres on paper surface was confirmed by SEM-EDS and its ability to act as a barrier against microorganisms was proved.

WOOD RESEARCH Volume 71, Number 2, 2026
YUQI SUN, XUANJIANG LIU, JIANING LI, TONGTONG LI, and HONGHAI LIU

Comparative Study on Characteristics of Vacuum and Conventional Kiln Drying of Non-Pith Heartwood of Rubberwood

This study compared the drying characteristics of non-heartwood rubberwood in vacuum drying (VD) and conventional kiln drying (CKD). The results show that overall, VD had a 21.6% higher drying rate than CKD. Especially below the fibre saturation point (FSP), VD’s rate was 1.56 times that of CKD because the low pressure in VD reduces the bound- water diffusion resistance. An ANOVA test shows that VD had significantly lower uniformity of moisture content (MC) in the longitudinal direction and higher uniformity of MC in the radial direction, especially when the MC drops below the FSP. VD also had significantly lower shrinkage ratios, colour change, and residual stress than CKD (p < 0.05). The greatest differences in shrinkage occurred at 20% MC. Overall, the colour change in VD was 30% lower, and the maximum decrease in the residual stress index in VD was 17.9% at 40% MC. These advantages of VD are likely related to its more uniform internal moisture gradient and low-oxygen environment.

WOOD RESEARCH Volume 71, Number 2, 2026
FRANCIS AKINYELE FARUWA, OLUSOLA OLORUNFEMI, and IYIOLA EBENEZER

APPARENT KINETIC MODELLING OF TORREFACTION BEHAVIOUR AND AXIAL VARIATION IN PINUS CARIBAEA AND LEUCAENA LEUCOCEPHALA UNDER REACTOR-SCALE CONDITIONS

Torrefaction improves the fuel properties of woody biomass. This study investigated kinetics of torrefaction-induced weight loss in Pinus caribaea and Leucaena leucocephala grown in Nigeria, between 225–300°C and axial stem position (top, middle, base). Oven-dried samples (300 g) were torrefied in a fixed-bed reactor under oxygen-limited conditions. Apparent rate constants were derived using a pseudo-first-order Arrhenius model. A total of 72 experimental runs were conducted. The sample weight loss increased with temperature. Pinus caribaea exhibited higher rate constants (0.0136–0.0761 min⁻¹) and lower activation energies (48.6–56.8 kJ.mol⁻¹) compared to Leucaena leucocephala. Axial variation significantly influenced activation energy, with base sections exhibiting 15–22% higher values than top sections. These findings demonstrate that biomass heterogeneity strongly affects reactor-scale torrefaction kinetics and should be considered in feedstock selection, process optimisation, and industrial-scale thermochemical conversion systems.

WOOD RESEARCH Volume 71, Number 2, 2026
SI XU, HAOYANG LI, JIAJIE CHEN, TONGYU XU, ZIYAN LUO, XIANGHE LIU, HAIDI JI, Bin Li, and Yan Yang

The Study on Timber Species used in Wooden Components of the Cultural Heritage Buildings of Shijia Courtyard, Xuzhou City

To clarify the timber species composition of wooden components in the cultural heritage buildings of Shijia Courtyard, and to provide support for the precise protection and restoration of these cultural heritage buildings, timber species were identified through microscopic observation. The results showed that the wooden components adopt typical native tree species including Pinus bungeana, Cunninghamia lanceolata, Acer spp., Populus spp., and Ulmus spp. This finding clarifies the timber species lineage of the building’s wooden components. This study fills the gap in basic research on the timber species used in the wooden components of Shijia Courtyard. It also provides scientific guidance for the restoration of wooden components and the selection of replacement materials in Shijia Courtyard and other similar folk cultural heritage buildings of the Ming and Qing dynasties.

WOOD RESEARCH Volume 71, Number 2, 2026
JAKUB BACA and PETER RANTUCH

The influence of gypsum board claddings and fasteners on the thermal degradation of a timber substrate

This article deals with the influence of gypsum board cladding and mechanical fastening on the thermal degradation of a timber substrate exposed to external radiant heat flux. Test specimens consisting of spruce wood protected by either standard gypsum board or fire-rated gypsum board were exposed to a heat flux of 50 kW·m⁻² in a cone calorimeter. Temperature development was monitored using thermocouples placed at the gypsum board–wood interface and inside the timber element within a pre-drilled hole with a diameter of 1 mm. In addition, thermogravimetric analysis of the individual components of the tested assembly was performed. The results indicate that the dehydration of gypsum significantly slows down heat transfer to the timber substrate. Samples protected by fire-rated gypsum board showed a slower temperature increase, lower CO production, and a greater residual thickness of timber compared to samples with standard gypsum board. No significant effect of the screw on temperature development or residual timber thickness was observed.

WOOD RESEARCH Volume 71, Number 2, 2026
IDA SKOTNICOVÁ, KRISTÍNA KYSEĽOVÁ, BRANISLAV NIŽNANSKÝ, LOTA CHRVALOVÁ, Štefan Šutý, and VERONIKA JANČÍKOVÁ

THE SYNERGISTIC EFFECT OF PULP BEATING AND POLYMER ADDITIVES ON MECHANICAL PROPERTIES AND ELASTICITY OF PAPER

The work investigates the possibilities of increasing the elasticity of paper by combining mechanical beating and the addition of some biopolymers directly to the pulp. The novelty of the approach lies in the volumetric modification of the pulp with biopolymers (gelatine, chitosan, PVA, CMC), which were not applied as a surface treatment, but were incorporated into the pulp suspension. The results confirmed that the increase in beating degree (up to 70°SR) and free drying significantly increase the relative elongation of the paper (an increase of 12.4%). The addition of gelatine increased the elasticity by 2.6%, especially at lower beating levels. The key finding is the synergistic effect of the combination of 1% chitosan and 5% CMC, which was the only combination that ensured a simultaneous increase in elasticity and strength (by 3.9 kN/m). This procedure represents an environmentally sustainable alternative for the production of high strength and elastic packaging materials.

WOOD RESEARCH Volume 71, Number 2, 2026
YOSAFAT AJI PRANATA, AMOS SETIADI, OLGA CATHERINA PATTIPAWAEJ, and AAN DARMAWAN HANGKAWIDJAJA

THE Compression Parallel to Grain Stress-Strain Model of TWELVE Tropical Wood Species with specific gravity Range of 0.39 to 0.67 g/cm3

This study aims to propose a compression parallel to grain stress-strain model equation for tropical wood species with a specific gravity range of 0.39 to 0.67 g/cm3. The stress-strain model is compiled from the results of experimental testing of twelve tropical wood species based on empirical data of stress-strain relationship curves from destructive testing. The test uses a reference according to ASTM D143-22. The results of this study are empirical equations for calculating and creating stress-strain relationship curves in the longitudinal direction of wood }compression parallel to grain).

WOOD RESEARCH Volume 71, Number 2, 2026
LEI YAN, QIANHUI HUO, JINGWEN SHA, LILI YU, SHUGUANG LI, and HUI LI

THE EFFECTS OF INTERFACE MODIFICATION ON THE PROPERTIES OF WASTE WOOD/POLYBUTYLENE SUCCINATE COMPOSITES

In this study, wood-plastic composites were prepared using waste wood powder (WWP) and polybutylene succinate (PBS). Three interfacial modifiers, γ-glycidoxy-propyltrimethoxysilane (KH560), isopropyl tri(dioctylpyrophosphate) titanate (CS201), and maleic anhydride-grafted PBS (MAPBS) were used to modify the interface of the composites and enhance the mechanical properties. The materials were characterized using infrared spectroscopy, three-point bending, and water absorption tests. The results indicated that all three interfacial modifiers were successfully grafted onto the wood powder surface, thereby influencing the mechanical properties. When the mechanical properties of the composites reached their optimal levels, the optimal loading levels of KH560, CS201, and MAPBS were 2%, 1%, and 2%, resp. At this point, compared to the unmodified composite, the elastic modulus increased by 9.44%, 15.03%, and 12.92%, resp; the flexural strength increased by 5.35%, 11.51%, and 8.91%, resp; the water absorption decreased by 4.88%, 3.68%, and 6.21%, resp; and the thickness swelling decreased by 4.56%, 3.08%, and 7.54%, resp.

WOOD RESEARCH Volume 71, Number 2, 2026
HUI LI, HONGXIA CUI, YU LIU, SHU-GUANG LI, JUN JIANG, HAO LYU, HUIJIE ZHANG, YONGQI SHI, and LILI YU

THE EFFECT OF COMPOSITE MODIFIED BORON-BASED WATERBORNE FLAME-RETARDANT COATING ON COMBUSTION PERFORMANCE OF BAMBOO DECORATIVE FILAMENT

To address the flammability of bamboo decorative filament, seven waterborne composite flame-retardant coating systems were developed using waterborne acrylic resin as the film-forming matrix, with boric acid, borax, ammonium polyphosphate (APP), nano-SiO2, and disodium octaborate tetrahydrate (DOT). The filament was treated as primer-only, topcoat-only, and combined primer/topcoat application. The combustion performance was evaluated by a cone calorimeter following ISO 5660-1: 2002. The results indicated that in the primer-only coating system, the boric acid/borax/disodium octaborate tetrahydrate composite system reduced total smoke production (TSP) by 11.90%, while the total heat release (THR) of the boric acid/borax/disodium octaborate tetrahydrate/ammonium polyphosphate composite system decreased by 18.83%. In the topcoat-only system, the boric acid/borax single-component system exhibited the optimal comprehensive performance, which the peak value of heat release rate (HRR) and the TSP decreased 13.54% and 8.24%, resp. In the combined primer-topcoat systems, THR reductions of 10.99% and 10.21% were achieved. Notably, nano-SiO2/boric acid/borax exhibited superior smoke suppression performance, with a 14.12% decrease in TSP, attributed to the synergistic physical barrier effect between the silicate network formed by nano-SiO2 and the boron-based glassy protective layer

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