Search Results (184)

Next to solid wood, laminated particleboard is the most widely used wood-based material in the furniture industry. Ensuring the high quality of the laminate surface after machining is of critical importance for furniture manufacturers, particularly prior to the edge banding process, as this process significantly influences the final aesthetic and functional quality of panel elements. The objective of this review article is to gather and evaluate the current state of knowledge regarding the influence of machining process parameters and the physical and mechanical properties of laminated particleboard on machining quality. Particular emphasis is placed on the occurrence of laminate damage, commonly referred to as delamination, a prevalent defect in the furniture manufacturing sector. Both categories of influencing factors—process-related and material-related—are analyzed within the context of the three primary technological processes employed in the woodworking industry, namely drilling, cutting, and milling. The analysis revealed that a persistent research gap concerns the relationship between machining quality and material parameters, particularly in the case of milling—a process of critical importance in the furniture industry. Full article

Acid hydrolysis can be more efficient than water hydrolysis, particularly in breaking down cured adhesives found in waste panels within a shorter reaction time, which could benefit large-scale industrial processes. This study evaluates the effects of various acid hydrolysis conditions on the thermal, physical, and chemical properties of recycled particles intended for particleboard production. Particleboards were recycled using oxalic acid and ammonium chloride at different concentrations and reaction times at 122 °C. The thermal stability of the particles was determined by thermogravimetric analysis. Particle size distribution, particle morphology, nitrogen content, pH and acid/base buffer capacity were analyzed. The effect of the recycled particles on the urea-formaldehyde (UF) curing was assessed using differential scanning calorimetry and the gel time method. The recycled particles exhibited a higher thermal degradation beyond 200 °C, indicating their thermal stability for manufacturing new panels. The acid treatments did not damage the anatomical structure of the particles, preserving the prosenchymatous elements. The nitrogen content of recycled particles decreased by up to 90% when oxalic acid was used, compared to raw board particles. Recycled particles exhibited a lower pH, with a maximum reduction of 44%. They also showed a decreased acid buffer capacity and an increased base buffer capacity compared to raw board particles. This effect was particularly pronounced in treatments that included ammonium chloride. The recycled particles did not significantly affect the peak polymerization temperature of the UF adhesive. However, some treatments affected the gel time of the adhesive, particularly those using 30% ammonium chloride. The results indicate that particleboards can be effectively recycled through acid hydrolysis, mainly with oxalic acid, which provides better results than hydrolysis using water alone. Oxalic acid showed increased selectivity in eliminating the cured UF adhesive, resulting in recycled particles suitable for manufacturing new panels. Full article

Plywood and particle boards, commonly used in construction and interior environments, are sources of indoor chemical emissions from synthetic adhesives, resins, and surface treatments. Among these, formaldehyde, classified as a group 1 carcinogen by the International Agency for Research on Cancer, and other compounds are associated with oxidative stress, inflammation, and organ toxicity. This study aimed to evaluate the toxicological and physiological effects of plywood and particleboard emissions in female C57BL/6 mice. The mice were exposed to formaldehyde, phytoncides, and untreated wood samples under short- (30–60 days) and long-term (120–180 days) conditions. Biological effects were assessed through histopathology of major organs, differential white blood cell counts, oxidative stress markers, antioxidant enzyme activities (catalase and glutathione peroxidase), liver and kidney function tests (alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine), and inflammatory cytokine profiling (interferon-gamma, tumor necrosis factor-α, interleukin (IL)-10, and IL-12p70). These findings revealed no significant pathological changes or systemic toxicity following long-term exposure. Minor elevations in hepatic and renal biomarkers were observed but remained within physiological limits. Antioxidant responses and cytokine fluctuations suggested mild adaptive and immunomodulatory effects. These results highlight the importance of reducing emissions from engineered wood products to improve indoor air quality and minimize potential health risks. Full article

This review examines the potential use of alternative wood raw materials, including fast-growing plantation species, juvenile wood, non-plantation species, and recycled wood, in the production of particleboard (PB) and oriented strand board (OSB). In light of the ongoing challenges faced by the wood-based industry in securing a stable and sustainable supply of raw materials, these alternatives present several advantages, such as cost-effectiveness, greater availability, and reduced reliance on natural forest resources. Fast-growing plantation species and juvenile wood are particularly suited for lightweight applications, while non-plantation species and recycled wood contribute to sustainability goals by lowering environmental impact and promoting resource efficiency. Nonetheless, the successful integration of these materials requires overcoming certain challenges, including variability in their physical and mechanical properties, as well as the need for tailored adhesive systems and processing parameters. This review examines strategies to optimize production processes and enhance the utilization of waste materials while emphasizing the role of alternative raw materials in advancing circular economy principles. The findings highlight the importance of future research to improve material knowledge, technological solutions, and industry practices, thereby supporting the sustainable development of the wood-based materials sector. Full article

Particleboards were developed by replacing a part of wood with various biomass residues, including coffee bean husks, spent coffee grounds, thistle, Sideritis and dead leaves of Posidonia oceanica. These materials were analysed to determine their physicochemical properties like the moisture content, pH, and buffer capacity, using standard laboratory techniques, while thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were also used for their further characterisation. The results revealed that all biomasses contained cellulose, hemicellulose, and lignin in varying proportions, along with differing degrees of crystallinity. To produce particleboards, the biomasses were bonded using two types of adhesives: (a) conventional urea-formaldehyde resin (UF) and (b) polymeric 4,4′-methylene diphenyl isocyanate (pMDI). Laboratory-scale, single-layer particleboards were manufactured simulating industrial production practices. These panels were evaluated for their mechanical and physical properties according to European standards. The findings showed a general reduction in mechanical performance when compared to conventional wood-based panels. However, panels made with coffee grounds and Posidonia showed improved resistance to thickness swelling after 24 h in water at 20 °C. Additionally, all experimental panels exhibited lower formaldehyde content than wood-based reference panels. This study demonstrated the feasibility of upcycling biomass residues as a sustainable alternative to virgin wood in the production of particleboard, providing a resource-efficient solution for specific interior applications within a circular economy framework. Full article

The growing volume of plastic waste from end-of-life vehicles presents environmental concerns, driving efforts to integrate recycled plastics. This study investigates the possibility of using recycled plastic from automotive parts (painted and unpainted bumpers, fuel tanks) as a 10% filler in the core layer of three-layer particleboards (P) and evaluates its impact on physical properties (water absorption—WA and thickness swelling—TS), mechanical properties (internal bonding strength—IB, modulus of rupture—MOR, modulus of elasticity—MOE and screw driving torque—SDT) and volatile organic compounds—VOC emissions. The boards were produced using conventional hot-pressing technology and analyzed according to applicable standards. Based on the results, the density of the reference (P) was 0.72 g·cm⁻³, while wood–plastic composites ranged from 0.70 g·cm⁻³ to 0.72 g·cm⁻³. After 24 h, WA reached 40% for reference (P) and from 36.9% (for (P) containing unpainted bumpers) to 41.9% (for (P) containing fuel tanks). TS reached 18% for (P) and from 16.8% (for (P) containing unpainted bumpers and fuel tanks) to 18.1% (for (P) containing painted bumpers). Plastic is a hydrophobic material and it is assumed that by increasing the proportion of plastic filler in the particleboards, the WA and TS of prepared boards will decrease. From the point of view of mechanical properties, values for (P) containing plastic filler were slightly lower compared to reference (P). The lowest value of IB (0.39 MPa) were reached for (P) containing painted bumpers. Plastic surface treatment could interfere with adhesion between the plastic and adhesive, weakening the bond in the core layer. For this reason, is preferable to use unpainted fillers, which provide better adhesive properties and higher structural integrity. VOC emissions from wood components consisted primarily of monoterpenes such as α-pinene, 3-carene and limonene. Adding 10% plastic to the particleboard did not increase overall VOC emissions. On the other hand, combining wood and plastic particles resulted in a reduction in overall VOC emissions. The findings confirm that recycled automotive plastics can be effectively incorporated into particleboards, maintaining standard performance while reducing reliance on virgin wood materials, making them a viable and sustainable alternative for furniture and interior applications. Full article

The effects of produced wood particles from three wood species—alder, birch, and larch—added in various amounts in the particle mixture consisting of spruce particles and three tested wood species in a particleboard core layer on selected physical and mechanical properties of particleboard were studied. In a laboratory, 16 mm thick three-layer urea–formaldehyde (UF)-bonded particleboards were produced at 5.23 MPa, 240 °C, and with a 10 s/mm pressing factor. Two particleboard surface layers consisted of fine spruce particles. In the particleboard core layer, spruce particles were combined with particles from alder, birch, and larch. The tested particleboards containing alder, birch, and larch were characterized by approximately identical thickness swelling and they met the requirements of the conventional values stated by major particleboard manufacturers of 8–10%. The tested particleboard in all variations met the minimum strength value P2 particleboard in three-point bending, which is conventionally set at 11.0 MPa. The tested particleboard also exceeded the required values of modulus of elasticity in bending and internal bond strength. Analysis of the relationships demonstrated by the density profile confirmed that all three investigated wood species are usable in a mixture of core particles of high-quality particleboard in the recommended amounts (10, 15, 20%). Full article

Eucalyptus wood particleboard (EPB), commonly used in indoor decoration, releases volatile organic compounds (VOCs) that can adversely affect indoor air quality and human health. This study systematically examined the VOC emission characteristics of EPB using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC-MS). A total of 65 VOCs were identified, with medium-volatility organic compounds (MVOCs) accounting for 28 compounds, low-volatility organic compounds (LVOCs) for 26, and high-volatility organic compounds (HVOCs) for 11. Terpenoids dominated the VOCs, comprising 78.46%, followed by aldehydes (10.77%) and alkanes (7.69%). Key odorant compounds (KOCs) were identified using the relative odor activity value (ROAV), with hexanal (ROAV = 100) and o-cymene (ROAV = 76.90) emerging as the most significant contributors to the overall odor profile. Thermal post-treatment at temperatures of 50–60 °C for durations of 6–12 h was found to be an effective method for reducing the residual VOCs and KOCs in the EPB, leading to a marked decrease in the peak areas of key odorants. The findings suggest several strategies for minimizing VOC emissions and eliminating residual odor, including reducing the use of miscellaneous wood materials, controlling the production of o-cymene, and employing thermal post-treatment at moderate temperatures. These measures provide a promising approach to reducing VOC and odor emissions from EPB and similar composite wood products, thereby enhancing their suitability for indoor applications. This study innovatively establishes an evaluation system for VOC emission characteristics in wood-based panels based on the ROAV. It elucidates the contribution mechanisms of key odor-active substances (e.g., hexanal and pentanal) and presents a thermal post-treatment process for source control, achieving simultaneous VOCs and odor elimination. A ROAV-guided hierarchical management strategy is proposed, providing scientific guidelines for the industrial production of high-quality particleboards with ultralow emissions (TVOC < 50 μg/m³) and minimal odor intensity (OI < Grade 3). Full article

Particleboard is an important forest product that can be reprocessed using wood processing by-products. This approach has the potential to achieve significant conservation of forest resources and contribute to the protection of forest ecology. Most current detection models require a significant number of tagged samples for training. However, with the advancement of industrial technology, the prevalence of surface defects in particleboard is decreasing, making the acquisition of sample data difficult and significantly limiting the effectiveness of model training. Deep reinforcement learning-based detection methods have been shown to exhibit strong generalization ability and sample utilization efficiency when the number of samples is limited. This paper focuses on the potential application of deep reinforcement learning in particleboard defect detection and proposes a novel detection method, PPOBoardNet, for the identification of five typical defects: dust spot, glue spot, scratch, sand leak and indentation. The proposed method is based on the proximal policy optimization (PPO) algorithm of the Actor-Critic framework, and defect detection is achieved by performing a series of scaling and translation operations on the mask. The method integrates the variable action space and the composite reward function and achieves the balanced optimization of different types of defect detection performance by adjusting the scaling and translation amplitude of the detection region. In addition, this paper proposes a state characterization strategy of multi-scale feature fusion, which integrates global features, local features and historical action sequences of the defect image and provides reliable guidance for action selection. On the particleboard defect dataset with limited images, PPOBoardNet achieves a mean average precision (mAP) of 79.0%, representing a 5.3% performance improvement over the YOLO series of optimal detection models. This result provides a novel technical approach to the challenge of defect detection with limited samples in the particleboard domain, with significant practical application value. Full article

The aim of the article was to test new types of rubber-containing particleboards created from waste materials, which positively contributes to environmental protection, saving primary resources and reducing production costs. This article focuses on the study of three-layer particleboards made from wood particles (spruce non-treated beams) and waste rubber granulates (tires, mixture of seals and carpets, internal flammable cables, external non-flammable cables). Urea–formaldehyde glue, melamine–formaldehyde glue, paraffin emulsion, and ammonium nitrate were used as a binders and excipients in the manufacturing of particleboards. In the core layer of each particleboard, 10% of the weight was made up of rubber granulate. Physical properties (density, water absorption, thickness swelling) and mechanical properties (internal bonding strength, modulus of rupture, modulus of elasticity, screw driving torque) were assessed from this perspective using current EN technical standards. According to the findings, the average densities of all particleboards were comparable to each other in a range from 0.692 to 0.704 g·cm⁻³. The lowest average water absorption and thickness swelling reached particleboards containing 10% of waste internal flammable cables, namely 32.79% for water absorption and 13.21% for thickness swelling. The highest average internal bonding strength reached particleboards without rubber filler and particleboards containing 10% of waste external non-flammable cables, namely 0.52 MPa for both types. The highest average modulus of rupture reached particleboards without rubber filler, namely 12.44 MPa. The highest average modulus of elasticity reached particleboards containing 10% of waste internal flammable cables, namely 2206.29 MPa, and the highest screw driving torque reached particleboards without rubber filler, namely 0.46 N·m for seating torque and 1.44 N·m for stripping torque. The results show that particleboards containing waste external non-flammable cables and particleboards containing waste internal flammable cables achieved comparable results to particleboards without rubber filler, which provides a good basis for a new way of utilizing this type of waste in the form of producing new wood–rubber composites. Full article

Recycling wood-based panels is essential for promoting the cascading use of wood, advancing the transition to a circular economy, and maximizing the efficient use of natural resources. While recycling particleboard has become a well-established industrial practice, recycling medium density fiberboard (MDF) panels presents challenges, particularly in preserving material quality. The aim of this research work was to investigate and evaluate the combined effect of recycled MDF fibers and urea–formaldehyde (UF) resin content on the performance characteristics of the panels. MDF recycling was conducted using hydrothermal hydrolysis and hammer mill refinement. Preliminary experiments revealed that the degradation of properties in recycled MDF panels is not uniform with the addition of recycled fibers. The panels retained their properties significantly with up to 20% recycled fiber content, while formaldehyde emissions decreased by 1.2%. Based on these findings, the optimization of recycled fiber and UF resin content was performed, revealing that the maximum allowable recycled fiber content through hydrothermal hydrolysis and hammer mill refinement is 24%, with a minimum UF resin content of 12%. This study highlights the potential for integrating recycled MDF fibers into new panels, contributing to more sustainable production practices. By optimizing the balance between recycled fiber content and UF resin, it is possible to produce MDF panels that meet industry standards while reducing the environmental impact. Full article

The enhanced use of wood residues from the timber industry contributes to mitigating the global climate crisis. Currently, bark, a by-product of the timber industry, is primarily burned for thermal energy generation. However, with the growing demand for lignocellulosic products and the emphasis on extending life cycles, it would be more beneficial to prioritize substantial uses of bark over thermal utilization. Although numerous methods for substantial bark utilization have been explored, a significant untapped potential remains. The extractives obtained through water extraction, for instance, can be applied to various further uses like biopolymers or medical applications. This study investigates the impact of hot water extraction on the mechanical and physical properties of bark-based panels, with the aim of extending the life cycle of tree bark and its valorization in bio-based composites. The findings demonstrate that hot water extraction can enhance the bending properties (modulus of rupture, modulus of elasticity) of bark-based panels. Additionally, the extractives obtained from the process have potential applications in the pharmaceutical and adhesive industries. The study also includes an LCIA that highlights the differences between the three scenarios addressed in this research, namely energy generation from bark-based biomass, extraction of bark, and use of extracted bark residues in the production of bark-based particleboard. Full article

Wood-based panels (WBPs) have versatile structural applications and are a suitable alternative to plastic panels and metallic materials. They have appropriate strength parameters that provide the required stiffness and strength for furniture products and construction applications. WBPs are usually processed by cutting, milling and drilling. Especially in the furniture industry, the accuracy of processing is crucial for aesthetic reasons. Ensuring the WBP surface’s high quality in the production cycle is associated with the appropriate selection of processing parameters and tools adapted to the specificity of the processed material (properties of wood, glue, type of resin and possible contamination). Therefore, expert assessment of the durability of WBPs is difficult. The interest in the automatic monitoring of cutting tools in sustainable production, according to the concept of Industry 4.0, is constantly growing. The use of flexible automation in the machining of WBPs is related to the provision of tools monitoring the state of tool wear and surface quality. Drilling is the most common machining process that prepares panels for assembly operations and directly affects the surface quality of holes and the aesthetic appearance of products. This paper aimed to synthesize research findings across Medium-Density Fiberboards (MDFs), particleboards and oriented strand boards (OSBs), highlighting the impact of processing parameters and identifying areas for future investigation. This article presents the research trend in the adoption of the new general methodological assumptions that allow one to define both the drill condition and delamination monitoring in the drilling of the most commonly used wood-based boards, i.e., particleboards, MDFs and OSBs. Full article

This study evaluated the fire properties of various particleboard (PB) types, including those made from sound spruce particles, degraded wood (brown and white rot), and recycled materials (blockboard, pallets, thermally modified wood, raw and laminated PBs, or mixtures). Laboratory-manufactured PBs showed densities ranging from 587 to 654 kg·m⁻³, with higher densities generally correlating with longer ignition times, although no statistically significant relationship was observed. Ignition times varied depending on material composition, with PBs made from sound spruce particles exhibiting the longest ignition times (103 ± 4.89 s). In contrast, PBs containing recycled or degraded particles ignited faster, influenced by additives such as adhesives and laminates. The burning rate peaked between 90 and 180 s, with PBs containing recycled raw PB particles and those degraded by brown rot showing the highest maximum burning rates (0.214 and 0.213 %·s⁻¹, respectively). Recycled laminated PBs reached peak burning rates in the shortest time, while control PBs required the longest time. Mass loss was higher in PBs with recycled or degraded particles, ranging from 47.52% to 51.71%, compared to 44.89% for control PBs. These findings highlight the trade-offs between fire resistance and the use of recycled materials, emphasizing the impact of additives on combustion behavior. Full article

This study investigated the effect of using juvenile pine and birch wood for the production of particleboards with lowered density, glued with urea-formaldehyde (UF) resin. The wood used was characterized by a number of annual rings ranging from 5 to 13, which ensured that only juvenile wood was used in the study. In addition to the basic characteristics of the wood particles obtained from this type of raw material, the density profiles of the manufactured particleboards, the internal bond, bending strength, modulus of elasticity, swelling, and water absorption after short-term water exposure (2 h) were also investigated. The results were compared to particleboards made from industrial wood particles from mature wood. It was found that particleboards made from juvenile pine wood exhibited higher internal bond than those made from juvenile birch wood. The bending strength of boards made from both types of juvenile wood was comparable to that of industrial particleboards; however, the modulus of elasticity of the particleboards made from juvenile pine was lower, which indicates reduced stiffness. These particleboards also showed higher swelling and water absorption, which may limit their durability under humid conditions. In contrast, birch boards exhibited lower internal bond, but their bending strength and modulus of elasticity were similar to those of industrial particles-based particleboards. Birch boards also showed slightly better water resistance than pine particleboards made from juvenile wood. However, their swelling remained higher than that of industrial particleboards. Overall, particleboards made from juvenile wood, especially birch, show good potential for further research. Full article