Search Results (338)

Despite the significant reduction in the overall cultivated area registered in recent decades, poplar still plays an important economic role in the Po Valley–Italy, where many farms involved in the plantation of this species are present, and the leading wood-processing industries are located. This paper describes the current organization of the poplar plywood wood-chain and explores the challenges in introducing new cultivars into the sector. In particular, it analyzes the main physico-mechanical properties of solid wood from five selected poplar clones (‘Dvina’, ‘Lux’, ‘Mella’, ‘Soligo’, ‘Taro’) that are characterized by fast growth, more sustainable agronomic practices, and increased disease resistance. These clones were cultivated in a seven-year-old linear plantation located in Northern Italy. This model, widely used in the past, is being re-proposed as a complement to the traditional system with square planting distances. The peeling yields and some performances of plywood manufactured from their veneers were also investigated. Results indicate that all clones have a much higher (from +30% to +56%) wood basic density than the ‘I-214’, which remains the lighter and preferred reference. These clones appeared also suitable for rotary cutting, but only ‘Lux’ and ‘Soligo’, and to a lesser extent ‘Mella’, provided veneers of the best quality class. Interesting mechanical features were registered for the sample plywood produced, especially in relation to the age of the harvested timber, which reached a diameter adequate for processing in a shorter time compared to the turnover adopted in conventional plantations. Except for ‘Dvina’, for all the clones, bending MOE and MOR were found to be comparable with those of spruce plywood made of similar thickness and the same lay-up. The findings suggest that the availability of new poplar cultivars and that of different cultivation models designed to enhance fast growth, when supported by targeted research and cooperation among multiple stakeholders (including farmers and industrial manufacturers), can lead to new applications where their plywood performances are valued. This, in turn, allows the resulting panels to meet specific needs in previously unexplored sectors, offering additional market opportunities. Full article

The growing demand for sustainable adhesives has increased interest in lignin as a renewable alternative to phenol in PF resins. In this study, lignins from hardwood, softwood, and bamboo were evaluated as partial replacements for phenol in plywood and paper panel applications. Softwood lignin exhibited the highest molecular weight and guaiacyl-rich structure, hardwood lignin contained more syringyl units, and bamboo lignin presented notable p-hydroxyphenyl content with minimal ash and sulfur. Incorporating up to 50% lignin increased resin viscosity and markedly shortened gel time from 136–152 s for neat PF resins to 58–139 s, depending on lignin type and resin formulation. Among the tested lignins, softwood lignin produced the strongest adhesives, whereas bamboo lignin resulted in the lowest formaldehyde emission (<0.6 mg/L). These findings demonstrate the feasibility of tailoring LPF resin performance by selecting lignin type. Full article

Disruptions in supply networks have caused many logistical and planning challenges in the last few years. The previous predictability of the shipping times of raw materials changed drastically due to various global issues, which affected many production areas, including the wood industry. This work is motivated by a case study of a Central European plywood production facility, where supply-side disruptions caused difficulties in meeting deadlines for downstream companies of the construction and furniture industry. As a result, the objective of production planners shifted towards mitigating the financial burden caused by cancellation penalties. Three MILP (Mixed-Integer Linear Programming) models and a genetic algorithm were developed to tackle the scheduling of a plywood production plant with raw material shipments and order deadlines. The novelty of the considered problem lies in the flexibility of swapping order deadlines from the same client, which was inspired by the real-life deals of the aforementioned company. The methods were tested on 120 benchmark instances of different sizes generated from real industrial data. The genetic algorithm terminated within 60 s for all instances and found the optimal or best-known solution in 71 of 80 short-horizon instances, while also remaining efficient on larger 30-day cases. As the solution approach is not specific to plywood production, it can be applied to scheduling problems in other fields as well, where similar disruptions can develop, and the production process features are covered by the Multi-Mode Resource-Constrained Project Scheduling Problem class. Full article

The reliability of hygrothermal models depends on the quality of their inputs. Conventionally, thermal and moisture properties are treated as temperature-independent, yet previous studies have shown that many of these properties are temperature-dependent. This paper investigates the impact of using temperature-dependent material properties on hygrothermal simulation results compared to standard temperature-independent properties at the building envelope level. A representative exterior wood-frame wall assembly is modelled with constant material properties, including water vapour permeability, sorption isotherm, and water absorption coefficient corresponding to values measured at 3 °C, 21 °C, and 45 °C, as well as a case in which the properties vary with temperature. The variation in hygrothermal response is evaluated under several scenarios, including different climates (Toronto and Vancouver, Canada), cladding types (fibre cement and stucco), sheathing materials (oriented strand board (OSB) and plywood), and with and without rain-penetration load. Results indicate that the variation attributed to temperature-dependent material properties was greater for Vancouver than for Toronto and increased with rain penetration. In particular, the choice of cladding seemed to have a greater impact than the choice of sheathing material, with stucco showing greater differences than fibre cement. Overall, however, the temperature at which material properties are defined has a minimal impact on hygrothermal simulation results and wall performance assessments, with maximum hourly differences in sheathing moisture content (MC) differences ranging from 1.18 to 4.32 wt% without rain penetration. These findings demonstrate that the use of temperature-dependent material properties does not have a significant impact on the hygrothermal simulation results or the performance assessment of exterior wood-frame wall assemblies. Full article

We estimate Oregon’s mass timber-related market value and economic contribution using two complementary valuation strategies and two IMPLAN implementations. Although mass timber includes CLT, glulam, nail-laminated timber, dowel-laminated timber, mass plywood panels, and structural composite lumber products, the empirical market-value estimates are centered primarily on CLT- and MPP-related evidence because these products have the most consistently available Oregon-specific data. Market value is inferred from production-based approaches, including facility capacity, Oregon’s share of U.S. output, and tracer-product scaling, and from demand-based approaches, including harvest routing, construction floor area, and U.S. demand allocation. These direct values are then entered into industry contribution analysis (ICA) for Oregon’s Engineered Wood Member and Truss Manufacturing sector and into analysis-by-parts (ABP) using a custom mass timber spending pattern. During 2018–2023, production-based estimates were larger and more variable than demand-based estimates, bracketing a plausible scenario range rather than providing a single point estimate. In 2022 price scenarios, all price-exposed cases scale proportionally with assumed panel prices. When identical direct values are used, ABP produces larger total employment and output effects than ICA because it routes more activity through upstream supplier industries. Output-per-worker sensitivity affects only direct employment in ABP. Forward scenarios for 2030 and 2035 indicate substantially larger total effects under ABP than ICA, but these estimates are conditional scenarios rather than forecasts. The framework provides a transparent basis for policy, investment, supplier-development, and workforce-planning discussions in an emerging industry with incomplete product-level data. Full article

This qualitative systematic review evaluates the potential of modular prefabricated OSB/plywood housing systems in low-technification, high-seismicity settings. These systems are promoted as low-carbon options for emerging contexts, and we assess how far the evidence supports that promise and under which conditions they can contribute to net-zero housing pathways. An adapted PRISMA 2020 workflow was applied to Scopus (TITLE-ABS, 2000–2025); 153 studies were synthesized in a table-first, coded matrix into axes for structural, digital fabrication, sustainability/circularity, and extrapolatable systems—supplemented by curated housing cases—with other EWPs used only for contrast. To address fragmentation and heterogeneity across domains, we developed a domain-based QA/QC instrument (STRUCTURAL, LCA, and FABRICATION) to judge whether studies provide minimally comparable evidence. Structural performance is relatively mature for certain patterns (calibrated FEM, cyclic tests, some 1:1 trials), whereas digital fabrication and LCA evidence remain partial: file-to-factory workflows rarely report verifiable QA/QC traceability, and most LCAs stop at A1–A3 with uneven treatment of A4, C/D, and biogenic carbon. Full convergence of adequate STRUCTURAL, LCA, and FABRICATION evidence within the same system type is rare, so both transferability to low-technification, seismic-prone settings and alignment with net-zero objectives must be characterized as conditional rather than established. The review identifies minimum multi-domain thresholds—technical robustness, whole-life LCA coverage, and verifiable QA/QC—as prerequisites for positioning modular OSB/plywood housing as a credible low-carbon pathway. These conclusions are limited by Scopus-only, English-language coverage and methodological heterogeneity, especially in the LCA. Full article

Kerf bending, achieved through precisely patterned cuts, enables the transformation of rigid plywood into flexible, adaptive surfaces for advanced design and ergonomic applications. This preliminary, exploratory study systematically investigates 56 laser-cut kerf geometries—spanning both traditional and novel parametric patterns—in birch plywood sheets of two thicknesses. Mechanical performance was evaluated via standardised testing, with statistical analyses (including Weibull and coefficient of variation) employed to interpret the pronounced variability observed in maximum load (Fmax) values, even among geometrically similar patterns. Due to the limitation of single-specimen destructive testing per pattern, the results should be understood as indicative trends within this experimental set, not as definitive rankings. Observed results suggest that kerf geometry and arrangement—rather than thickness or gross material removal—are the primary determinants of flexibility and strength. Notably, specific parametric and meander-type patterns demonstrated promising balances of deformation capacity and mechanical reliability within this limited dataset. The inherent limitations of experimental replication and natural material heterogeneity are explicitly acknowledged, and the findings are intended as a foundation for future, more statistically robust investigations. This work provides a comparative framework and initial design guidance for kerf-based plywood structures and identifies key priorities for further research in replication, material selection, and real-world applications. Full article

To develop a fully green and non-toxic wood adhesive with improved water resistance and bonding performance for soybean meal (Glycine max (L.) Merr.)-based adhesives, oxidized tannin (OTN) was obtained by the laccase treatment of waxberry tannin (TN), a natural polyphenolic polymer, and then blended with soybean meal (SM) to prepare an oxidized tannin–soybean meal adhesive (OTS). Laccase-mediated oxidation converted the tannin polymer into quinone-rich oxidized polymeric structures, which reacted with amino groups in soybean meal proteins through Michael addition and Schiff base reactions to form a covalently crosslinked polymeric network. Under the optimal conditions of a laccase dosage of 10%, an oxidation time of 6 h, an OTN:SM mass ratio of 0.5:1, and a hot-pressing temperature of 160 °C, plywood bonded with OTS exhibited a wet shear strength of 0.85 MPa at 63 °C, representing a 136% increase over that of the neat soybean meal adhesive, and showed slightly higher bonding performance than the commercial urea-formaldehyde (UF) resin under boiling-water conditions. Structural analyses (FT-IR and XPS) verified quinone formation and carbon–nitrogen single and double bonds. Thermal analyses (DSC and TGA) revealed improved curing reactivity and significantly enhanced thermal stability compared with the neat soybean meal adhesive. Full article

Conventional adhesives for plywood are mostly derived from petroleum-based materials and commonly suffer from formaldehyde emission, posing threats to the environment and human health. In this study, a renewable resource, Xanthoceras sorbifolium Bunge oil, was used as the raw material. A high-performance bio-based adhesive was successfully prepared by synthesizing Xanthoceras sorbifolium Bunge oil dimethacrylate (MXOEA) as a reactive diluent, blending it with acrylated epoxy Xanthoceras sorbifolium Bunge oil (AEXO), and introducing 2-isocyanatoethyl methacrylate (IEM) to enhance crosslinking. The effects of the MXOEA/AEXO ratio and the IEM addition level on the properties of the adhesive and the resulting plywood were systematically investigated. The results showed that when the mass ratio of AEXO to MXOEA was 3:7, and the IEM content was 10%, the adhesive exhibited the best bonding performance: the resulting plywood achieved a modulus of rupture of 68.85 MPa, a modulus of elasticity of 8086 MPa, and dry and wet bonding strengths of 3.21 MPa and 2.32 MPa, respectively. Mechanistic analysis indicated that the introduction of IEM moderately reduced the viscosity of the adhesive system. Meanwhile, the isocyanate groups in IEM reacted with the hydroxyl groups on the wood surface, forming a chemical crosslinking structure at the adhesive-wood interface, which is considered one of the reasons for the improved mechanical properties of the plywood. This study provides a formaldehyde-free, high-performance bio-based adhesive derived from Xanthoceras sorbifolium Bunge oil for the field of wood-based composites. Full article

To address the hazards posed by formaldehyde emissions from wood-based products to human health and the indoor environment, research on wood adhesives has focused on developing green and eco-friendly alternatives. However, the limited water resistance and bonding strength of bio-based or glyoxal-based adhesives have hindered their practical application. In this work, a co-condensation method was employed to prepare glyoxal-based co-condensation adhesive incorporating starch and a small amount of chitosan as synergistic reinforcing agents to enhance their cross-linking extent. Considering cost control, the starch content was varied to adjust the adhesive properties. When the molar ratio of glyoxal to urea was 2:1 and the mass ratio of starch to urea was 0.5:1, the adhesive exhibited optimal bonding strength, reaching 1.48 MPa after immersion in cold water for 24 h and 0.91 MPa after treatment in 63 °C hot water for 3 h. These values exceeded the requirements of the Chinese national standard (GB/T 9846-2015, ≥0.7 MPa). Structural analysis indicated Schiff base and aldol condensation reactions among amino groups in chitosan and urea and hydroxyl and aldehyde groups in starch and glyoxal, forming chemical covalent cross-links that contributed to improved water resistance and bonding strength of plywood samples. Furthermore, the excellent penetration ability of the adhesive could promote the formation of a uniform and dense cross-linked network under hot-pressing conditions, thereby enhancing the overall performance of the plywood. Full article

With non-rainfall water (NRW), principally dew and fog, serving as an important water source, especially in arid and semiarid regions, factors that may increase the NRW yield may have important hydrological and ecological consequences. On the other hand, dew and fog may also have hazardous effect on inorganic and human-made materials that may undergo corrosion and/or degradation. It has long been noted that dew and fog are affected by neighboring objects, the effect of which was, however, only barely explored. Hypothesizing that it may principally be linked to the sky view factor (SVF) (determining, in turn, substrate temperature and heat flow) and, therefore, to the angle that is formed between the collecting substrate and the height of the neighboring objects, a set of square boxes (30 × 30 or 60 × 60 cm) was constructed. The boxes had variable heights, forming angles of 15°, 30°, 45°, 60°, and 75° between 6 × 6 × 0.1 cm cloth attached to a substratum (10 × 10 × 0.2 cm glass plate overlying 10 × 10 × 0.5 cm plywood) at the center of each box and the top walls of the box. NRW that accumulated at the cloths was compared with cloths placed in the open, serving as control. Another set served to measure the plate temperatures. A clear decrease in NRW, with an angle corresponding to a third-degree polynomial equation, was found (r² = 0.998). Taking 0.1 mm as the threshold for vapor condensation (dew), and taking the average maximal NRW as measured for two years in the Negev (0.20 mm), angles of ≥45° will suffice to impair condensation. However, with the projected decrease in NRW with global warming, even angles of ≥30° may impair condensation in 1–2 decades. While it may decrease the dew amounts and subsequently negatively affect the vegetation in forest clearings and wadis or canyons, it may decrease the exposure of construction materials to corrosion and/or degradation, thus exerting a positive effect on construction materials in urban settings. Full article

Plywood has emerged as a key sustainable material in modern building. Yet, ensuring its consistent performance requires rigorous quality control of the rotary-cut veneers used in its manufacture. This task is complicated by the high-speed nature of industrial conveyors, where motion blur and the complex, varying textures of eucalyptus wood drastically reduce the effectiveness of real-time surface inspection. This study proposes an intelligent, real-time defect detection system specifically optimized for the diverse defect morphology of eucalyptus veneers. A lightweight model, YOLOv11-DMS-Veneers, was developed by integrating MobileNetV4 as the backbone, a Dynamic Head for multi-scale feature extraction, and a Shape-IoU loss function to precisely localize irregular defects like cracks and knots. Additionally, an ERD video enhancement framework (combining ESRGAN, RIFE, and DnCNN) was implemented to mitigate motion blur in dynamic environments. Experimental results demonstrate that the proposed model achieves a mean Average Precision (mAP@50) of 96.0% and a Precision of 95.7% with a low computational cost of only 4.5 GFlops, significantly outperforming traditional algorithms. Notably, the detection precision for challenging linear cracks reached 93.9%. In dynamic tests at conveyor speeds up to 24 m/min, the video enhancement strategy increased the average detection confidence by 0.288, maintaining a maximum confidence of 0.890. This technology offers a robust solution for the automated quality control of eucalyptus veneers, facilitating the production of high-performance plywood and advancing the efficient application of engineered wood in the building industry. Full article

This study evaluates bamboo–coir hybrid composite panels developed for formwork applications using an 80:20 fiber–matrix ratio and a 50:50 bamboo-to-coir distribution. The novelty of this study lies in the combined assessment of formwork-relevant mechanical performance, Mode I and Mode II fracture behavior, finite element validation and post-fracture microstructural correlation for a high fiber volume fraction natural fiber hybrid panel. Mechanical, durability, fracture, numerical and microstructural investigations were performed and benchmarked against 10 mm thick construction-grade plywood. The hybrid panels exhibited a density of 805 ± 10.84 kg/m³, which is within 0.7% of plywood, a tensile strength of 50.20 ± 2.85 MPa, representing an increase of 41.8% over plywood, and a flexural strength of 38.60 ± 2.10 MPa, corresponding to an increase of 12.9% as compared to plywood. The impact energy absorption of hybrid panels was 7.85 ± 0.62 J, which is 26.6% greater than plywood. Mode I fracture testing yielded a fracture toughness of 456.65 ± 15.42 J/m², corresponding to an increase of 9.3% over plywood, while Mode II fracture toughness yielded a value of 792.42 ± 30.18 J/m², representing an increase of 13.7% over plywood. Finite element predictions deviated from experimental load–displacement responses by 5–13%. SEM observations identified fiber bridging, fiber pullout and interfacial sliding in the hybrid panels, consistent with the measured fracture energy values. The results indicate that bamboo–coir hybrid panels satisfy the mechanical and fracture performance requirements for reusable formwork systems. Full article

This study evaluates the environmental performance of plywood manufactured from thermally modified birch veneers using the Thermovuoto^® process, bonded with a birch bark–derived suberinic acids adhesive. Framed within the context of sustainable materials development and the circular bioeconomy, the research examines the potential of bio-based adhesive systems as alternatives to conventional phenol–formaldehyde resins. A cradle-to-grave life cycle assessment (LCA) was performed, encompassing birch bark harvesting, adhesive production, veneer thermal modification, plywood manufacturing, distribution to the customer, and end-of-life management. Environmental impacts were modelled using openLCA 2.4 in combination with the Ecoinvent 3.11 database, in accordance with ISO 14040 and ISO 14044, applying the ReCiPe 2016 v.1.03 (H) midpoint life cycle impact assessment method. The results indicate that the birch bark extraction stage, particularly ethanol use derived from potato fermentation, constitutes the dominant contributor across all assessed impact categories. Overall, the LCA outcomes suggest that thermally modified, suberinic-acid-bonded birch plywood represents a promising niche bio-based material, with clear potential for further environmental improvement through process optimization. Full article

Traditional steel–wood composite formwork systems often exhibit mechanical imbalances, such as high strength with insufficient stiffness or high stiffness with low toughness, under both ultimate and serviceability limit states. To address the deficiency, this paper proposes a novel reinforced steel–wood composite formwork system (RSWC-FS). The system features a multi-layer plywood panel, ribbed cold-formed thin-walled Q235 steel secondary wales, and double-channel steel primary wales, interconnected by high-strength bolts to create a surface-to-surface bonded interface. This design enhances load transfer efficiency and mitigates stress concentration. Field testing was conducted on cast-in-place shear walls and frame columns, and corresponding finite element models were established in ANSYS for numerical analysis. The results demonstrate that the RSWC-FS delivers stable mechanical performance. The maximum stress of shear walls reaches 42.57 MPa and that of columns 49.98 MPa, while the corresponding displacements are 4.719 mm and 1.541 mm, all of which remain well within the allowable limits. Through an inverse analysis calibration process, optimal load partial factors of 1.26 for shear walls and 1.31 for columns are recommended, significantly reducing the deviation between calculated and measured values. The proposed RSWC-FS effectively resolves the mechanical imbalance inherent in traditional steel–wood composite formwork systems and demonstrates considerable potential for practical engineering application. Full article