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.
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.
This study evaluated the ACQ treatability of 24 local timber species through vacuum pressure impregnation and correlated preservative retention and penetration with physical and anatomical wood properties. Retention ranged widely from 0.478 kg m⁻³ (Bridelia retusa) to 14.980 kg m⁻³ (Cullenia ceylonica and Cupressus macrocarpa). Based on retention and Chrome Azurol S (CAS) penetration assessment, species were classified into four treatability classes. One-way ANOVA confirmed highly significant differences in density (F₂₃,₄₈=199.79; p<0.001), moisture content (F₂₃,₄₈=48.04; p<0.001), and ACQ retention (F₂₃,₄₈=82.75; p<0.001) across species. Pearson correlation analysis revealed a very strong positive relationship between fibre wall thickness and wood density (r=0.955; p<0.05) and a strong negative relationship between fibre lumen diameter and density (r= −0.903; p=0.001), demonstrating that fibre morphology is the dominant determinant of wood density. Neither density (r= −0.411; p=0.163), moisture content (r = 0.005; p = 0.987), total ray area (r=0.097; p=0.789), total vessel area (r= −0.021; p=0.932), fibre wall thickness (r=0.082; p=0.725), nor fibre lumen diameter (r=0.302; p=0.183) produced statistically significant correlations with ACQ retention, indicating that preservative uptake is governed by the combined interactive influence of multiple anatomical and chemical wood properties rather than any single parameter. Cullenia ceylonica, Cupressus macrocarpa, and Ficus amplissima were identified as the most effectively treatable species, classified as very easy to treat (Class 4, retention >10 kg m⁻³) with full penetration exceeding 25 mm. These findings provide a species-specific treatability database for Sri Lankan timber and highlight the need for multi-variable modelling in future preservative research.
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 & centerdot;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.
In this study, wood-plastic composites were prepared using waste wood powder (WWP) and polybutylene succinate (PBS). Three interfacial modifiers, gamma-glycidoxypropyltrimethoxysilane (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 is prone to decay, flammability and poor dimensional stability, which restrict its high-value application in furniture manufacturing, architectural decoration and other fields. As an advanced wood modification technology, wood silicification modification can significantly improve wood properties by impregnating silicon-based precursors into the interior of wood and forming SiO2 in situ. This paper reviews the latest research progress of wood silicification modification, elaborates on the structural characteristics of two types of silicon sources (organic and inorganic), sorts out the key points of current mainstream silicification processes, and analyses the improvement effects of wood silicification modification on wood properties such as dimensional stability, decay resistance and flame retardancy. It is proposed that future research is going to focus on the development of green and efficient new technologies and the exploration of organic-inorganic interface regulation mechanisms, aiming to develop multi-functional intelligent silicified wood.
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).
This paper reports on an experimental study of a model of a historical timber roof segment subjected to progressive weakening of the central tie beam. A three-frame specimen was tested under controlled loading, short-term sustained full load, and sequential cutting of the middle tie beam. Close-range photogrammetry was combined with inductive displacement sensors and conventional control measurements. The study examined the agreement of optical and contact measurements, redistribution of displacement demand to the adjacent frames, and the temporary residual stability provided by lathing after complete failure of the middle tie beam. Across the tie-beam midspans, the mean absolute difference between inductive and paired optical measurements ranged from 0.07 to 0.40 mm, with a maximum point-wise deviation of 1.39 mm. After complete failure, additional settlement of the two intact frames reached 4.28 and 3.97 mm relative to the pre-cut full-load state, indicating longitudinal redistribution through the lathing.
Mannan is the main hemicellulose in coniferous wood. Spruce mannan was extracted and characterized by FT-IR, SEM and specific surface area test. FT-IR showed it was branched galactoglucomannan; SEM revealed its layered surface and rod-like polymerization units with spherical tops at high magnification; it had small specific surface area and large pore size. Hydrolysis experiments showed spruce mannan inhibited commercial second-generation cellulase (max inhibition rate 22.22%), with inhibition related to hydrolysis time, enzyme dosage and mannan amount. Tween 80 alleviated this inhibition (min inhibition rate 8.69%), promoted β-glucosidase at high concentration (max promotion rate 28.57%), and greatly reduced mannan’s hydrolysis effect (inhibition rate down to 31.82%). This study provides a basis for improving mannan utilization and biomass energy conversion.
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 degrees 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.
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 degrees 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.
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.
This study presents a modified approach for enhancing the fire performance of white poplar wood (Populus alba L.) through the in situ formation of MgAl layered double hydroxides (LDHs) within the wood structure. The treated wood exhibited significantly improved fire properties. The limiting oxygen index (LOI) increased from 19% to 45%, while cone calorimetry results showed reductions of approximately 65% in peak heat release rate (HRR), 58% in total heat release (THR), 80% in maximum average rate of heat emission (MARHE), and 80% in total smoke production (TSP) compared to untreated poplar wood. The enhanced fire performance is attributed to the formation of a protective char layer and the presence of inorganic residues derived from LDH decomposition, which influences the thermal degradation and combustion behaviour of the wood. The results demonstrate that this simple modification approach provides an effective method for improving the fire performance and smoke suppression properties of fast-growing wood species.
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 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 & times; 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 dm(3)/kg), indicating its strong potential for industrial application.
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.
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 & times;100 & times;10 mm and 300 & times;100 & times;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.
Employing rapid surface loading (160 degrees 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 degrees 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.
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.
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.
This study investigates the impact of top soundboard thickness on the modal parameters of violins. By analysing variations in plate thickness, the research explores how these changes influence modal frequencies, damping characteristics, and overall acoustic properties. Findings indicate that increased thickness results in lower modal frequencies and better damping, which may affect sound quality. The study references established research on violin acoustics and discusses the structural implications of varying plate thicknesses, particularly concerning the effects of string tension. These insights contribute to a deeper understanding of violin construction and offer potential guidelines for optimising instrument design to achieve desired tonal qualities.
