最新刊期
卷 38 ， 期 6 ， 2024
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摘要：The lack of nanopores and low specific surface area of natural wood limit its functional applications in many fields. In this study, 2,2,6,6-tetramethylpiperidinyl-1-oxyl radical (TEMPO)-mediated oxidation was applied to generate nanopores in wood and increase its specific surface area by in-situ fibrillation of cellulose microfibril bundles within the cell walls of balsa wood (Ochroma pyramidale). The microstructure and chemical composition of the TEMPO-oxidized wood were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS). Moreover, the effect of TEMPO-oxidation treatment on the pore structure of wood cell wall was investigated using a specific surface area and pore size analyzer. The results showed that the honeycomb-like cellular structure of the wood was well preserved after oxidation treatment, while the microfibrils in the wood cell wall were successfully individualized, resulting in a highly nanofibrillated network structure with microfibril diameters ranging from 20 to 40 nm. The TEMPO-oxidized wood exhibited a highly mesoporous structure with a high specific surface area of 96.92 m²/g, which is about 72 times higher than that of natural wood. This study provides a novel approach to regulating the nanostructure of wood cell walls for developing porous wood-based materials.关键词：balsa wood;cell wall nanostructure;pore structure;TEMPO oxidation;cellulose microfibrils1|0|0发布时间：2025-01-17 -
摘要：This paper presents the investigation on the waterlogged wood from Chinese Cruiser Zhiyuan. The information of wood species, moisture content, and basic density were analyzed. The species and degradation degree of the waterlogged wood were classified as mildly decayed teak and severely decayed banyan. The samples of waterlogged wood were pre-frozen at －20℃ and －79℃ for 48 hoours. The drying speed and the shrinkage rate of the samples were measured and analyzed. The results showed that pre-freezing treatment significantly reduced the shrinkage rate but had no significant effect on the drying rate. The impacts of two freezing temperatures were minimal, therefore the treatment result could be achieved by using －20℃ freezing treatment for energy saving. Although the deformation of the severely decayed banyan samples reduced during drying after pre-freezing treatment, the final deformation rate was considerably large due to the poor strength of samples. The pre-freezing process was not suitable for severely decayed samples. An optimized treatment process need to be further studied.关键词：waterlogged wood;pre-freezing treatment;drying;Chinese Cruiser Zhiyuan0|0|0发布时间：2025-01-17 -
Effect of Pressing Process of Impregnated Paper on Surface Bonding Strength of Ultra-Thin Fiberboard
摘要：The ultra-thin fiberboard, a novel wood material made with high precision, advanced processing, and high added value, has emerged in recent years. This material features a thin thickness, high density, and a smooth surface, making it widely applicable in the decorative materials industry. To investigate the critical parameters and the underlying mechanism of surface bonding performance for melamine-impregnated film paper-coated ultra-thin fiberboard, an L16 (45) orthogonal test was conducted to examine the effects of hot-pressing temperature, time, and pressure. Additionally, single-factor tests were employed to analyze the impact of the sanding process and the initial moisture content of the ultra-thin fiberboard on the surface bonding strength of the melamine-impregnated film paper-coated ultra-thin fiberboard. The results indicated that the surface bonding strength was primarily affected by the hot-pressing temperature. Under the optimal conditions (hot pressing time: 10 seconds, temperature: 205°C, pressure: 2.7 MPa), the surface bonding strength reached its maximum value of 1.95 MPa. The surface bonding strength of ultra-thin fiberboard with 180-mesh sanding was 1.5 times higher than that without sanding. When the initial moisture content of the ultra-thin fiberboard was approximately 8%, the surface bonding strength was optimal. Furthermore, SEM and contact angle analysis revealed that sanding treatment increased surface roughness, while an initial moisture content of approximately 8% enhanced hydrophilicity, facilitating stronger mechanical interlocking and interfacial wetting between the ultra-thin fiberboard and the melamine-impregnated film paper.关键词：ultra-thin fiberboard;hot-pressing process;sanding treatment process;initial moisture content;impregnated film paper;surface bonding strength2|0|0发布时间：2025-01-17 -
摘要：In this study mica powder and diatomaceous earth (composite powder) were physically blended to modify urea melamine formaldehyde (MUF) resin at different mass ratios (3∶7, 5∶5, 7∶3) and quantities (5%, 10%, 15%). Multiple characterization methods were used to investigate the properties of MUF resin before and after modification and medium density fiberboards (MDF) made with this resin. The effects of mass ratio and quantity of the blended powder on the properties of fiberboards was discussed. The results showed that adding blended powder to MUF resin increased its viscosity and solid content, extended curing time, and reduced free formaldehyde content. Minor changes in functional groups of fiberboards prepared with the modified adhesive were found. The thermal stability was improved. When the mass ratio of mica powder to diatomaceous earth was 7∶3 with the quantity of 5%, the modulus of rupture, the modulus of elasticity, and the internal bonding strength of the MDF were 27.11, 2 523, and 0.81 MPa, respectively, which were 9%, 7%, and 53% higher than without modification. The 24-hour water absorption thickness expansion rate was 8.5%. The physical and mechanical properties met the performance requirements of the ordinary MDF used in a dry state according to the GB/T 11718—2021 “Medium Density Fiberboard”. The formaldehyde emission decreased from 3.50 mg/100 g to 2.85 mg/100 g, which was a decrease of 19%, meeting the E0 level requirement of T/CNFPIA 1001—2019 “Formaldehyde Emission Limits for Artificial Boards”.关键词：blended powder;diatomite;mica powder;MUF resin;medium density fiberboard0|0|0发布时间：2025-01-17 -
摘要：In this study, oriented strand board (OSB) was made by adding amine copper quant (ACQ) and phenol formaldehyde resin (PF) in order to investigate the effects of ACQ additions (2, 4, and 6 kg/m3) and PF additions (8% and 10%) on the physical, mechanical, and preservative properties of OSB. The study revealed that the physical and mechanical properties of the OSBs achieved the requirements of OSB/4 class boards in the GB/T 41715—2022 “Oriented Strand Board”, although these property values decreased as the amount of preservative increased. Meanwhile, the addition of ACQ preservative improved the preservative properties of OSB. When the PF and ACQ content was at 10% and 6 kg/m3 respectively, the average mass loss rate of the samples after 12 weeks of infection by brown rot fungus was finally reduced to 1.72%, which was only 22.7% of the control samples. The results of average mass loss rate and morphological analyses indicated that the physical encapsulation of PF and the synergism of ACQ enhanced the preservative properties of the samples. This study added data to enhance the understanding of the physical, mechanical, and preservative properties of OSB, specifically regarding improvements in durability and long-lasting utilization.关键词：oriented strand board;ACQ;mechanical properties;preservative properties;cured property;mass loss rate0|0|0发布时间：2025-01-17 -
摘要：The compressive bearing capacity of timber columns with holes is a key research focus in ancient timber structures. In this study, larch wood (Larix sp.), commonly used in ancient buildings, was selected as the experimental material. To investigate the effect of vertical holes on the compressive bearing capacity of timber columns, an artificial opening method was used to simulate internal hole defects. The compressive test was conducted using digital speckle image correlation (DIC) in conjunction with a mechanical testing machine. The compressive failure mechanism in timber columns with vertical holes was examined through the macroscopic and microscopic mechanical properties. The results indicated that, under the conditions of this experiment, the effect of the hole’s cross-sectional area on the ultimate load of timber column was greater than that of the hole’s longitude direction. Fold failure was the primary compressive failure mode for timber columns with vertical holes, followed by the transverse tearing and oblique shear failure of the wood as displacement increased. Fold failure and oblique shear failure were primarily caused by the buckling of the wood tracheid cell walls, while transverse tearing failure primarily extended longitudinally along the wood tracheid cells resulting in an irregularly serrated cross-section. Additionally, the strain field distribution indicated that stress concentrations in the vertical, transverse stress, and shear stress occurred at the ends of holes, which demonstrated the effectiveness of the DIC method in predicting the damage location in ancient building wood components. This study provides a solid foundation for the protection and repair of ancient timber structures.关键词：timber column with holes;compressive bearing capacity;digital speckle image correlation (DIC);vertical hole;ultimate load;failure mode;strain field0|0|0发布时间：2025-01-17 -
摘要：A diaphragm board fastened to the frame by nails or screws in modern wood structure is the main factor determining the diaphragm structure stiffness, which significantly impact the seismic performance of the whole wood structure. In this study, the single shear specimens of nail joints were fabricated with the bamboo-wood composite board (BWC) and oriented strand board (OSB) on larch dimensional-lumber frame. The monotonic loading tests were carried out to investigate the effects of nail size, panel material, and grain direction on the nail joints properties. The results showed that the initial shear stiffness and ductility coefficient of nail joints of BWC along grain direction were greater than those across grain direction, however these scenarios reversed at the maximum load. There was no obvious difference between grain direction in OSB. When the nail diameter increased, the main shear performance of BWC nail joints increased, while the stiffness and ductility coefficients decreased. To minimize the risk of cracking of the larch wood frame, CN75 nails were recommended for the connection of the 28 mm thick BWC to the frame. The allowable load was 44% higher than that of the 18 mm-thick OSB nail joints. Furthermore, the initial stiffness was one time higher than that of 18 mm thick OSB; The shear failure mode of the BWC nail connection did not have the phenomenon of pulling through the board, and the nails mainly crush the wood and were bent to pull out at the shear plane. The Hassanieh model can simulate the shear load displacement curve of BWC, which provides prime data for structural analysis of BWC nail joints.关键词：bamboo-wood composite board(BWC);nail connection;shear performance;seismic diaphragm0|0|0发布时间：2025-01-17
RESEARCH PAPERS
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摘要：Moldable poplar veneer with the excellent folding formability was produced through delignification combined with air drying and water immersion processes. Molded wood products and 3D structural materials were created using a wavy mold and integrating a hot-press assembly technique. Various characterization methods were employed to analyze the macro- and micro-morphology of the moldable poplar veneer, as well as the structural stability and compressive strength of the 3D structural materials. The results showed that the moldable poplar veneer exhibited the superior tensile strength (190.67 MPa) in longitudinal direction of the wood, which were nearly five times that of untreated veneer. The compressive strength of a single-layer 3D structural material was about 0.97 MPa, demonstrating excellent structural stability and mechanical strength as a supporting component. Additionally, the multi-layer 3D structural materials, produced through layer-by-layer assembly, offer advantages such as lightweight and high strength, providing a novel approach to the high-value-added utilization of wood.关键词：Poplar veneer;moldable veneer;molding;3D structural materials;mechanical properties0|0|0发布时间：2025-01-17 -
摘要：The special scrimber for liquefied natural gas (LNG) ships is used as a load-bearing and insulation material between the cryogenic gas storage tankers and the ship hull. Currently, this material is mainly imported from abroad. In this study, Populus tomentosa veneers with thicknesses of 1.3 mm and 1.8 mm were used to prepare special wood scrimber for LNG ships. The microstructure, water absorption and mechanical strength were evaluated and compared. The results indicated that the performance of the special wood scrimber prepared from 1.3 mm veneers was superior, with a water absorption rate of 6.6%, vertical loading and bending resistance of 212.4 MPa and 17.5 GPa respectively, a compressive strength of 255.6 MPa, and a shear strength of 38.2 MPa. However, the shear strength and water absorption of wood scrimber-1.3 are still lower than those of imported products. Furthermore, during the mechanical strength test, it was found that the wood scrimbers prepared from two types of veneers were both crushed and exhibited some cracks.关键词：Populus tomentosa veneer;LNG ship;special wood scrimber;water absorption;mechanical properties;pore;Crack0|0|0发布时间：2025-01-17
RESEARCH BRIEFING
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摘要：Combining intelligent furniture manufacturing with the current digital workshop situation, the key to improving the operational efficiency of customized furniture workshops is to enhance the level of cyber-physical integration and build a digital twin model. To this end, this study proposes an architectural model, operating mechanism, and key technologies for a digital twin workshop in intelligent furniture manufacturing. It discusses the application of a digital twin workshop in customized furniture manufacturing. It analyzes the process from four aspects: the selection of process parameters and decision-making in intelligent furniture manufacturing, dynamic workshop scheduling for the flexible manufacturing of customized furniture, failure prediction and health management of equipment, and logistics and distribution. It promotes the rapid establishment of a digital workshop for customized furniture manufacturing. This study provides a theoretical foundation for the construction and application of a digital twin workshop in customized furniture manufacturing.关键词：customized furniture;digital twin workshop;operation mechanism;key technology;application0|0|0发布时间：2025-01-17
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