Search Results (72)

Cutting beech plywood using abrasive water jet (AWJ) technology represents a significant area of research due to increasing demands for precision, quality, and environmental sustainability in manufacturing processes within the woodworking industry. AWJ technology enables non-contact cutting of materials without causing thermal deformation or mechanical damage, which is crucial for preserving the structural integrity and mechanical properties of the plywood. This article investigates cutting beech plywood using technical methods using an abrasive water jet (AWJ) at 400 MPa pressure, with Australian garnet (80 MESH) as the abrasive material. It examines how abrasive mass flow rate, traverse speed, and material thickness affect AWJ lag, which in turn influences both cutting quality and accuracy. Measurements were conducted with power abrasive mass flow rates of 250, 350, and 450 g/min and traverse speeds of 0.2, 0.4, and 0.6 m/min. Results show that increasing the abrasive mass flow rate from 250 g/min to 350 g/min slightly decreased the AWJ cut width by 0.05 mm, while further increasing to 450 g/min caused a slight increase of 0.1 mm. Changes in traverse speed significantly influenced cut width; increasing the traverse speed from 0.2 m/min to 0.4 m/min widened the AWJ by 0.21 mm, while increasing it to 0.6 m/min caused a slight increase of 0.18 mm. For practical applications, it is recommended to use an abrasive mass flow rate of around 350 g/min combined with a traverse speed between 0.2 and 0.4 m/min when cutting beech plywood with AWJ. This balance minimizes jet lag and maintains high surface quality comparable to conventional milling. For thicker plywood, reducing the traverse speed closer to 0.2 m/min and slightly increasing the abrasive flow should ensure clean cuts without compromising surface integrity. Full article

The aim of this study was to evaluate the suitability of eight softwood species most commonly used by Greek timber industries, including furniture manufacturers and companies producing roundwood, sawn timber, and plywood. The analysis was based on integrated Multi-Criteria Decision Analysis (MCDA), using a combined approach of the PROMETHEE method and the Analytical Hierarchy Process (AHP), taking into consideration some important criteria that affect timber quality. According to the PROMETHEE complete ranking, Aleppo pine (Pinus halepensis Mill.) achieved the best performance under the selected criteria among the examined softwood species, underlying the importance of Aleppo pine to the Greek timber industry. Our findings could be highly beneficial to the wood industry, promoting the recovery and advancement of the forest sector in general, taking into account that sustainable wood supply is lower than the total biomass available in Europe. Policymakers should prioritize the selection of conifer tree species that can strengthen Greece’s forestry sector, promote sustainable management practices, and increase the economic value derived from the country’s diverse forest resources. Full article

The construction sector is swiftly evolving toward more sustainable practices. Life cycle assessment (LCA) is essential for assessing the environmental impact of construction materials. A crucial factor in this context is the wear-out coefficient (WOC), which indicates a material’s reusability and directly affects the amount of material used during a project’s life cycle. This study contrasts conventional timber formwork with alternative materials, including aluminum, steel, plywood, plastic, and various hybrid systems. The environmental consequences are assessed throughout several life cycle stages—manufacturing, transportation, usage, and disposal—utilizing a 3D building information modeling (BIM)-integrated life cycle assessment (LCA) framework. This method facilitates adherence to green building standards and corresponds with the Sustainable Development Goals (SDGs). Hybrid Option 2 (timber–aluminum–steel) and Hybrid Option 4 (steel–plastic–aluminum) distinguish themselves as superior choices, integrating environmental efficacy with resilience. Aluminum exhibits the lowest WOC (0.13), signifying its exceptional reusability and lack of environmental impact. The results highlight the need to incorporate BIM and LCA in formwork material planning to improve sustainability, prolong the service life, and maximize resource efficiency in construction. Full article

The plywood industry is one of the most significant sub-sectors of the forestry industry and serves as a cornerstone of sustainable construction within a bioeconomy framework. Plywood is a panel composed of multiple layers of wood sheets bonded together. While automation and process monitoring have played a crucial role in improving efficiency, data-driven decision-making remains underutilized in the industrial sector. Many industrial processes continue to rely heavily on the expertise of operators rather than on data analytics. However, advancements in data storage capabilities and the availability of high-speed computing have paved the way for data-driven algorithms that can support real-time decision-making. Due to the biological nature of wood and the numerous variables involved, managing manufacturing operations is inherently complex. The multitude of process variables, and the presence of non-linear physical phenomena make it challenging to develop accurate and robust analytical predictive models. As a result, data-driven approaches—particularly Artificial Intelligence (AI)—have emerged as highly promising modeling techniques. Leveraging industrial data and exploring the application of AI algorithms, particularly Machine Learning (ML), to predict key performance indicators (KPIs) in process plants represent a novel and expansive field of study. The processing of industrial data and the evaluation of AI algorithms best suited for plywood manufacturing remain key areas of research. This study explores the application of supervised Machine Learning (ML) algorithms in monitoring key process variables to enhance quality control in veneers and plywood production. The analysis included Random Forest, XGBoost, K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Lasso, and Logistic Regression. An initial dataset comprising 49 variables related to the maceration, peeling, and drying processes was refined to 30 variables using correlation analysis and Lasso variable selection. The final dataset, encompassing 13,690 records, categorized into 9520 low-quality labels and 4170 high-quality labels. The evaluation of classification algorithms revealed significant performance differences; Random Forest reached the highest accuracy of 0.76, closely followed by XGBoost. K-Nearest Neighbors (KNN) demonstrated notable precision, while Support Vector Machine (SVM) exhibited high precision but low recall. Lasso and Logistic Regression showed comparatively lower performance metrics. These results highlight the importance of selecting algorithms tailored to the specific characteristics of the dataset to optimize model effectiveness. The study highlights the critical role of AI-driven insights in improving operational efficiency and product quality in veneer and plywood manufacturing, paving the way for enhanced industrial competitiveness. Full article

This study evaluates the potential of various hardwood combinations in plywood production in response to increasing wood demand and a changing roundwood supply in Central Europe. Six different combinations of nine-layer plywood were produced using 2 mm rotary-cut veneers from lime (Tilia spp.), Norway maple (Acer platanoides), European hornbeam (Carpinus betulus), Sycamore maple (Acer pseudoplatanus), mountain ash (Sorbus aucuparia), and European beech (Fagus sylvatica) with phenol–formaldehyde adhesive, and they were compared to silver birch (Betula pendula) plywood as a reference. The raw densities of the test panels varied between 0.85 and 1.04 times the reference density (795 kg m⁻³). Flexural strengths (the modulus of rupture, MOR) ranged from 68 N mm⁻² to 104 N mm⁻² for a parallel fibre orientation and 44 N mm⁻² to 61 N mm⁻² for a perpendicular fibre orientation of the top layers. The modulus of elasticity (MOE) ranged from 7160 N mm⁻² to 11,737 N mm⁻² for the parallel fibre orientation and from 4366 N mm⁻² to 5575 N mm⁻² for the perpendicular orientation. The tensile shear strength varied between 0.91 and 1.69 times the reference (1.49 N mm⁻²). The thickness swelling after 24 h was higher in all variants than the reference (6.4%), with factors between 1.39 and 1.64. A significant effect was observed when layers with a lower density were arranged on the outside and those with a higher density in the core, resulting in a more uniform density distribution across the cross-section after hot pressing. This created a levelling effect on mechanical and physical properties, especially the modulus of rupture (MOR) and the modulus of elasticity (MOE). Overall, the evaluated hardwood combinations demonstrated comparable properties to the birch reference and industrially produced birch plywood. Full article

Coffee silverskin, a by-product of coffee processing, was studied using microscopic (SEM), spectroscopic (FTIR), and thermogravimetric (TGA, DSC) methods to assess its use as a substitute filler in the manufacturing of plywood. TGA showed that the material was compatible with plywood hot pressing temperatures (140 °C) and that it was thermally stable up to 50 °C, with a notable decomposition event at 335 °C. Functional groups like hydroxyl and carbonyl were detected by FTIR analysis, indicating possible hydrogen bonds and chemical adaptability. DSC analysis confirmed structural alterations by highlighting endothermic processes associated with dehydration and an exothermic transition over 150 °C. Coffee silverskin substituted rye flour in plywood adhesive compositions at different concentrations (0%, 1%, 5%, 10%, and 20%). Due to the structural and chemical constraints of the filler, larger concentrations (10% and 20%) dramatically lowered bonding strength, whereas low silverskin amounts (1% and 5%) attained strengths equivalent to rye flour, reaching up to 5 N mm⁻², according to internal bond strength tests. SEM images revealed smaller, more fragmented, and porous silverskin particles than larger, compact rye flour particles, which affected mechanical interlocking and adhesion. The findings point to coffee silverskin as an environmentally friendly and performance-balancing substitute for conventional fillers, especially at medium levels. Full article

The study of biomimetics allows for the creation of various structures inspired by nature. This work investigates the impact of using a bio-inspired tool path for manufacturing porous plates via 3D printing. The Bouligand (or plywood-like) structure is prevalent in several biological components. Structures that mimicked the Bouligand design concerning the tool path were printed and compared to uniform plates produced with a rectilinear pattern through mechanical testing. Quasi-static and dynamic tests were conducted on specimens with infill densities ranging from 25% to 100%. Results indicated that the Bouligand pattern displayed superior specific energy absorption at 75% infill density. This bio-inspired path pattern also provided excellent elongation during quasi-static and dynamic failure—the fracture pattern of the bio-inspired path adhered to the Bouligand structure. In contrast, brittle failure was demonstrated by the specimen with a rectilinear pattern at varying infill percentages, while the bio-inspired pattern enhanced the toughness of the polymer specimens. Full article

The construction industry faces significant challenges, including environmental sustainability, rising material costs, and a shortage of skilled labor. Digital fabrication technologies offer innovative solutions to address these issues by reducing raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an Environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, this study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and abiotic depletion potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low-clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities. Full article

In this study, a simple one-step blend of isolated soy protein and sucrose was used directly as a wood adhesive for plywood manufacturing. The bonding performance, water resistance, curing performance, and thermal stability of the adhesive were evaluated. The preparation process of the plywood was optimized and the curing mechanism was also investigated. The results demonstrate the following: (1) Sucrose was successfully converted into furan compounds, especially 5-hydroxymethylfurfural (5-HMF), which underwent a sufficient cross-linking reaction with the SPI, and this was the key during the curing of the adhesive. (2) The effect of hot-pressing temperature on the bonding performances was the most significant and played a key role in the success of the test, followed by hot-pressing time, solid content, and adhesive loading. (3) In this study, 200 °C was the critical point at which the adhesive obtained good wet bonding strength and was also the critical temperature at which the effective conversion of sucrose into 5-HMF occurred. (4) The optimum preparation parameters of plywood were a hot-pressing temperature of 216 °C, a hot-pressing time of 1 min/mm, a solid content of 50%, and adhesive consumption of 220 g/m². Using this process, a bonding strength in warm water of 1.74 MPa, a bonding strength in boiling water of 1.50 MPa, and a wood failure rate of more than 80% were obtained for the plywood. Full article

Rye flour is a commonly used filler in plywood production, made from finely ground rye grains. It enhances glue viscosity, ensuring even distribution and better adhesion, which improves the plywood’s mechanical properties, dimensional stability, and resistance to warping. Additionally, rye flour increases the plywood’s strength and durability, making it more resistant to mechanical damage and external factors. Its affordability and availability further support its widespread use in plywood production. However, the growing availability of new raw materials has sparked interest in alternative fillers, especially considering food waste challenges caused by low demand or poor household management. This study explores the potential of spirulina, bamboo flour, lupine flour, and coconut flour as alternative fillers to rye flour, being part of the food chain, in three-layer plywood production. Plywood panels were manufactured using birch and pine veneers, urea-formaldehyde resin, and varying filler contents (10, 15, and 20 parts by weight/pbw). Key mechanical properties were evaluated, including modulus of elasticity (MOE), modulus of rupture (MOR), shear strength, density profile, and filler water absorption. The highest MOE for hardwood plywood was observed with coconut flour (20 pbw, 17,228 N mm⁻²). Conversely, the lowest MOE values were recorded for coniferous plywood with spirulina (8440 N mm⁻²). For MOR, the best performance in softwood was achieved using lupine flour (10 pbw, 113 N mm⁻²), while coconut flour yielded the highest MOR in hardwood plywood (20 pbw, 177 N mm⁻²). Spirulina exhibited the lowest MOR (72 N mm⁻², 15 pbw). Shear strength peaked with lupine and coconut flour. The filler composition determines adhesive properties and bond performance through water absorption, structural interactions, and filler content optimization. These findings emphasize the potential for fine-tuning alternative fillers to achieve desired mechanical performance, ensuring sustainable and efficient plywood production. These also demonstrate the potential of certain alternative fillers, particularly coconut and lupine flours, excluded from the food value chain, in improving specific properties of plywood. Full article

Larch tannin, a valuable forest product resource, offers the benefits of being natural, renewable and environmentally friendly. With growing environmental concerns, the widespread use of phenolic resins in the wood industry has been limited due to the depletion of fossil resources and formaldehyde emission issues. In this study, larch tannin was modified using a NaOH/urea solution to enhance phenolic resin properties. The curing properties and thermal stability of the adhesives were analyzed using a differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA), and the formaldehyde emissions were also measured. The results showed that this treatment effectively reduced the resin’s gel time. LTPF-U-4 resin demonstrated the highest bonding strength of 1.09 MPa and exhibited low formaldehyde emissions, thereby meeting the requirements for Class I plywood (≥0.7 MPa) and complying with the E0 grade of plywood standards as outlined in the China National Standard GB GB/T 17657-2013. The sodium hydroxide/urea-treated larch tannin substitution improved the bonding performance of the LTPF-U resins; its impact on bonding strength is limited. Nevertheless, the treatment significantly reduces the formaldehyde emissions of plywood bonded with LTPF-U resins. The NaOH/urea treatment not only reduced the thermal stability of the resin but also improved its curing properties and lowered its curing temperature. This research offers valuable insights for developing modified phenolic resins, which have significant practical implications. Full article

Most wood-based panels were currently prepared using aldehyde-based adhesives, making the development of natural, renewable, and eco-friendly biomass-based adhesives a prominent area of research. Herein, the phenolic resin was modified using a soybean protein isolate (SPI) treated with a NaOH/urea solution through a copolymerization method. The physicochemical properties, chemical structure, bonding properties, and thermal properties of the soybean protein-modified phenolic resin (SPF-U) were analyzed using Fourier transform infrared spectroscopy, thermogravimetric analysis, and formaldehyde emission tests. The results indicated that the molecular structure of the soy protein isolate degraded after NaOH/urea solution treatment, while the gel time was gradually shortened with increasing NaOH/urea solution-treated soy protein isolate (SPI-U) dosages. Although the thermal stability of the soy protein isolate was lower than that of the phenolic resin, the 20% SPF-U resin demonstrated better thermal stability than other modified resins. The PF modified with 30% SPI-U (SPF-U-3) exhibited the lowest curing peak temperature of 139.69 °C than that of the control PF resin. In addition, all modified PF resins exhibited formaldehyde emissions ranging from 0.18 to 0.38 mg/L when the SPI-U dosage varied between 20% and 50%, thereby meeting the E0 plywood grade standard (≤0.5 mg/L). Full article

Problems with the availability of raw materials on the Polish market have forced wood industry producers to search for new, previously unused species of wood that meet the functional requirements of the target products. Therefore, it is necessary to conduct research on products whose structure is different from the popular offerings on the market. The goal of this study was to analyze the influence of the thickness of Scots pine veneers, also with Alder interlayer variants, on Young’s modulus and stiffness values of plywood-like composites dedicated to flooring applications regarding statistically based quality control of the products. The variables in this research are the thickness of the veneer, which creates the structure of the base layer of flooring materials, and the kind of wood used. This research looked at basic mechanical properties determining the suitability of flooring materials: modulus of elasticity and stiffness. Because both these parameters describe the product quality, the analyses were based on the normal distribution (containing kurtosis) and the creation of Shewart Control Charts for each parameter. Analyses of control charts provide information on whether the projected production process is stable and is able to give predictable results. In turn, the analysis of the kurtosis value allows us to determine whether Young’s modulus and stiffness values obtained for the products are as close as possible to the values assumed by the manufacturers. The thickness of veneers in the base layer of flooring composites can be enlarged, allowing production to be simplified and more environmentally friendly. New types of layered composites for flooring, manufactured by rotary cutting, without the need for quality assessment, with a minimum number of layers, and additionally verified with Shewart Control Charts, may be applied to production. Presented studies show that veneers of different quality classes, having plywood-like structures, can be used for flooring materials and that the thickness of the veneers in the base layer can be increased. In this way, wood can be used without the need for quality classification and with fewer production processes. Full article

This study experimentally investigated the effects of selected factors on the bending moment capacity (BMC) of case furniture joints. The main aim was to explore mixed applications of wood-based materials and fasteners in manufacturing case furniture to reduce material costs. The study examined the effects of the face member material—particle board (PB), plywood (PL), and block board (BB)—edge member material (PB, PL, and BB), and joint shape (T-shape and L-shape) on BMC. Additionally, the study evaluated the effects of joint type (two eccentrics (TE), two dowels (TD), and one eccentric and one dowel (ED)), and material type (PB, PL, and BB) on BMC for L-shaped joints. The results showed that joint shape and face member material significantly affected the BMC of case furniture joint. The BMCs of T-shaped joints were significantly greater than those of L-shaped joints, regardless of the material of the face and edge members, except when the face member was made of PL. For L-shaped joints with PL face members, the BMCs were significantly higher compared to others. Joints constructed with TE exhibited significantly higher BMC compared to ED and TD for the same material type. For PB, TE joints exhibited an increase of approximately 3.0 Nm and 2.0 Nm compared to TD and ED, respectively. For PL, TE showed an increase of 9.1 Nm and 4.1 Nm compared to ED and TD, respectively. For BB, the increases were 7.0 Nm and 6.6 Nm compared to ED and TD. The BMC of joints made with PL and constructed with TE and ED was significantly greater than those of BB, followed by PB. However, for joints assembled with TD, there was no significant difference among the three materials. The ratios of BMC for joints constructed with ED compared to the half-sum of TE and TD were 0.73, 1.04, and 0.79 for PB, PL, and BB, respectively. These results suggest that the face member material predominantly influences the BMC of case furniture joints, indicating the potential to reduce costs by combining different materials and joint types. Full article

In recent years, 3D printing technology has become very important in many fields of science, manufacturing, design, medicine, aviation, sports, etc. Furniture design and manufacturing are also not left out of this trend. In this study, the results of bending moments and stiffness of joints of thin structural elements connected by 3D printing with polylactic acid (PLA) connectors are given. The connectors are newly developed, and information on their strength characteristics is lacking in the literature. Ten joints were investigated, made with 9 and 12 mm plywood and 6 mm MDF. The tested joints constructed by 3D-printed connecting elements show a high strength under arm compression bending load, between 44.16 and 24.02 N·m. The stiffness coefficients of joints with 3D-printed connecting elements are between 348 and 145 N·m/rad and are higher than those of conventional detachable mitre joints but lower than those of glued ones. The type of filling of the hollow section of the connecting elements and the wall thickness influenced the joints’ strength and stiffness. Reducing the width of the connecting elements from 40 to 30 mm and the inner radius between the arms from 2 to 1 mm does not significantly affect the joints’ strength and stiffness coefficients. Full article