WOOD RESEARCH Volume 71, Number 3, 2026
QIANHUI HUO, LEI YAN, LILI YU, HUI LI, Jun Li, and SHU-GUANG LI

THE EFFECTS OF INTERFACIAL MODIFICATIONS ON THE PROPERTIES OF BAMBOO FIBER /WASTE TETRA PAK /PLA COMPOSITES

In this study, BF/TP/PLA ternary composite was constructed utilizing bamboo fiber (BF) as the reinforcing phase and waste Tetra Pak (TP) along with polylactic acid (PLA) as the matrix. The effects of different interfacial modification methods on the properties of the composites were systematically investigated. Bamboo fibers were modified using a silane coupling agent (KH570), nano-SiO2, and compatibilizers (MAH-g-PLA, MAH-g-PE). The composites were subsequently fabricated via hot pressing, and their mechanical properties, water absorption, chemical structure, and micromorphology were characterized. The results showed that after KH570 treatment, the flexural modulus and flexural strength of the composites increased by 15% and 32%, respectively. Following the introduction of compatibilizers, the water absorption was further reduced, and the thickness swelling rate was significantly improved. Optimal comprehensive performance was achieved at a nano-SiO2 content of 1 wt%; the flexural modulus reached 2524.1 MPa, exceeding the requirement of Chinese standard LY/T 3275-2021 for outdoor wood-plastic composites (≥2500 MPa), while the water absorption decreased to its lowest value (11.3%). Furthermore, interfacial bonding became more compact.

WOOD RESEARCH Volume 71, Number 3, 2026
SÜHEYLA ESİN KÖKSAL, ORHAN KELLECİ, and YASEMİN ÖZTÜRK

Surface Preparation for Lamination of OSB with Phenol Formaldehyde Film and Melamine Formaldehyde Decorative Paper

This study investigated the lamination of oriented strand board (OSB) surfaces using phenol formaldehyde impregnated polymer film (PF) and melamine formaldehyde impregnated decorative paper (MF). To enhance surface smoothness, OSB panels were sanded and treated with different putty systems, including commercial wood putty, polyvinyl acetate (PVAc), and polyvinyl alcohol (PVA). Ground hazelnut shell and furnace slag particles were incorporated as fillers at a 10% loading level. Results revealed that PF film laminated samples demonstrated significantly superior physical and mechanical performance compared to MF laminated boards. Among all specimens, the sample, prepared exclusively with wood putty and laminated with PF film, achieved the best overall performance, exhibiting the lowest water absorption (WA) and thickness swelling (TS) alongside the highest modulus of rupture (MOR), modulus of elasticity (MOE), abrasion resistance, and surface soundness (SS) values. Although hazelnut shell and furnace slag additions generally reduced putty system performance, their incorporation into PVAc and PVA-based formulations improved certain surface properties.

WOOD RESEARCH Volume 71, Number 3, 2026
SAIP NAMI KARTAL, EKİM ELÇİN SOYTÜRK, YUKO ITO, and WAKAKO OHMURA

Preliminary Evaluation of Copper Leaching from Commercially Available Wood Species in Japan Treated with Copper Azole Wood Preservative

This study examined copper fixation and leaching in wood treated with copper azole (CuAz) and copper sulfate (CuSO₄), emphasizing the effects of wood species and post-treatment conditions. Five Japanese softwoods, including Sugi, Hinoki, and Douglas fir, were assessed under three conditions: unfixed, ambient-fixed, and heat-treated (60°C for 3 days). Copper fixation was defined as the proportion of non-leachable copper remaining after standardized leaching, with release rates measured via leachate analysis. Results showed that post-treatment condition is the dominant factor controlling copper stabilization. Heat treatment significantly enhanced fixation and reduced leaching across all species and preservative types, indicating improved bonding between copper ions and wood components. Ambient fixation was often insufficient. Sugi sapwood showed the highest leaching, while Hinoki heartwood exhibited the greatest retention. Overall, CuAz outperformed CuSO₄, underscoring the importance of formulation in improving copper stability and durability.

WOOD RESEARCH Volume 71, Number 3, 2026
DOAN VAN DUONG and MASUMI HASEGAWA

VARIATION IN BASIC DENSITY AND TRANSVERSE SHRINKAGE AMONG SIX EUCALYPTUS CLONES PLANTED IN VIETNAM

This study examined clonal and radial variation in basic density (BD) and transverse shrinkage among six Eucalyptus clones grown under uniform conditions in north-central Vietnam. A total of 30 ramets were sampled, and 196 small clear specimens were prepared from positions near the pith and the bark. Partial and total shrinkage in tangential (Tn, T) and radial (Rn, R) directions were determined following ISO 13061-13:2017. Basic density (BD) ranged from 0.39 to 0.50 g/cm³ and increased consistently from pith to bark. Tangential shrinkage (Tn: 4.45–5.83%; T: 5.64–6.85%) showed greater variation among clones than radial shrinkage (Rn: 2.95–3.32%; R: 3.89–4.72%). Clone U1427 showed the highest BD while also presenting the lowest shrinkage values, suggesting excellent dimensional stability and considerable potential for utilization in solid wood and lumber production in northern Vietnam.

WOOD RESEARCH Volume 71, Number 3, 2026
FIRDUS HAVERAJ, GERTI XHIXHA, and Dritan Ajdinaj

Short notes. COMPARATIVE STUDY OF THE IMPACT OF THERMAL MODIFICATION PARAMETERS ON THE THERMAL CONDUCTIVITY OF DIFFERENTWOOD COMPOSITE PANELS

This study examined how thermal modification influenced the thermal conductivity of plywood, oriented strand board, and medium-density fiberboard. Samples were exposed to two temperature levels, 130°C and 180°C, for 20 and 40 min, while untreated panels were retained as controls. Measurements were carried out under controlled laboratory conditions using the steady-state hot-box method. The thermal modification consistently reduced thermal conductivity across all materials, which suggests improved insulation properties. The observed reductions varied. OSB exhibited the most significant overall decrease in thermal conductivity, while plywood displayed relative stability; conversely, MDF demonstrated a marked reaction under the more rigorous treatment conditions. The type of material used had the most significant overall statistical effect. The duration of the treatment was more important than the temperature. The interaction between temperature and time did not achieve statistical significance within the parameters of the experiment; conversely, interactions involving material type were significant.