Search Results (247)

To improve the intelligence level of particleboard inspection lines, machine vision and artificial intelligence technologies are combined to replace manual inspection with automatic detection. Aiming at the problem of missed detection and false detection on small defects due to the large surface width, complex texture and different surface defect shapes of particleboard, this paper introduces image super-resolution technology and proposes a super-resolution reconstruction model for particleboard images. Based on the Transformer network, this model incorporates an improved SRResNet (Super-Resolution Residual Network) backbone network in the deep feature extraction module to extract deep texture information. The shallow features extracted by conv 3 × 3 are then fused with features extracted by the Transformer, considering both local texture features and global feature information. This enhances image quality and makes defect details clearer. Through comparison with the traditional bicubic B-spline interpolation method, ESRGAN (Enhanced Super-Resolution Generative Adversarial Network), and SwinIR (Image Restoration Using Swin Transformer), the effectiveness of the particleboard super-resolution reconstruction model is verified using objective evaluation metrics including PSNR, SSIM, and LPIPS, demonstrating its ability to produce higher-quality images with more details and better visual characteristics. Finally, using the YOLOv8 model to compare defect detection rates between super-resolution images and low-resolution images, the mAP can reach 96.5%, which is 25.6% higher than the low-resolution image recognition rate. Full article

This study investigates the effects of suberic acid residue (SAR) additions on structural single-layer particleboard (like the P5 type, according to EN 312) properties, specifically the water absorption (WA), thickness swelling (TS), modulus of rupture (MOR), modulus of elasticity (MOE), screw withdrawal resistance (SWR), and internal bond (IB) strength. The results indicate that finer SAR fractions (1/0.25 and 2/1) reduce the WA after 2 h of soaking, while larger fractions increase the WA after 24 h, with only the smallest fraction meeting the TS standards. The MOR values (18.5–19.6 N mm⁻²) and MOE (3627–3811 N mm⁻²) remain largely unaffected by SAR additions, while the SWR shows minimal variation across various SAR fractions (203–209 N mm⁻¹). The IB strength improves with SAR additions, peaking at 2.10 N mm⁻² for the 5/2 fraction, though slightly decreasing with the largest fraction (8/5). A density analysis reveals an increased surface density with finer SAR fractions, benefiting the surface strength but reducing the core uniformity with larger fractions. These findings suggest that SAR-enhanced particleboards could be valuable in applications requiring moisture resistance, such as bathrooms, kitchens, and exterior cladding. Further research should explore optimizing the SAR concentration, combining it with hydrophobic agents, and examining its long-term stability under varying environmental conditions to enhance its structural performance for sustainable building applications. Full article

Wood-based particleboards (PBs) are widely used in construction and interior applications, yet their durability, particularly against biological degradation, remains a challenge. Recycling wood and incorporating degraded particles from rotted wood can potentially enhance PB sustainability and align with circular bioeconomy principles. This study investigates the biological resistance of the three-layer, laboratory-prepared PBs with varied amounts of particles, from sound spruce wood to particles, and from spruce logs attacked by brown- or white rot, respectively, to particles from recycled wooden composites of laminated particleboards (LPBs) or blockboards (BBs), i.e., 100:0, 80:20, 50:50, and 0:100. The bio-resistance of PBs was evaluated against the brown-rot fungus Coniophora puteana, as well as against a mixture of moulds’ “microscopic fungi”, such as Aspergillus versicolor BAM 8, Aspergillus niger BAM 122, Penicillium purpurogenum BAM 24, Stachybotrys chartarum BAM 32, and Rhodotorula mucilaginosa BAM 571. PBs containing particles from brown-rotten wood or from recycled wood composites, particularly LPBs, had a partly enhanced decay resistance, but their mass loss was nevertheless more than 30%. On the other hand, the mould resistance of all variants of PBs, evaluated in the 21st day, was very poor, with the highest mould growth activity (MGA = 4). These findings suggested that some types of rotten and recycled wood particles can improve the biological resistance of PBs; however, their effectiveness is influenced by the type of wood degradation and the source of recycled materials. Further, the results highlight the need for improved biocidal, chemical, or thermal modifications of wood particles to enhance the overall biological durability of PBs for specific uses. Full article

Corner joints and edge banding are essential components that significantly impact the strength, durability, and aesthetic appeal of particleboard furniture. This review examines the critical role of edge banding in enhancing the performance of corner joints, which are fundamental to the overall quality of panel furniture. A targeted literature search was conducted across key databases, including the Web of Science Core Collection (WoS CC), Scopus, and Google Scholar, focusing on scientific resources in the technical and biotechnical sciences. The selection of joint types, materials, and construction methods can substantially influence both the structural integrity and visual design of the furniture. Well-designed corner joints improve durability and longevity by ensuring that furniture can withstand various forces and loads without failure or deformation. These joints enhance the aesthetics of furniture by providing seamless and visually appealing connections between different elements. Edge banding is vital for reinforcing corner joint strength, as different materials exhibit varying degrees of resistance to impact, scratches, and abrasion, thereby safeguarding furniture surfaces. Also, edge banding contributes to the furniture’s longevity, ensuring durability during use as well as through disassembly and transport during remodeling or relocation. This review aims to consolidate existing knowledge and establish parameters for future research on the quality and performance of corner joints and edge bands in particleboard furniture. Full article

The demand for innovative products from renewable sources has motivated research development to create new sustainable materials. Cassava starch (CS) has been widely used for bonding and composing different types of products. Particleboards produced from cocoa (Theobroma cacao), wood wastes, and CS adhesives can be an environmentally correct and economically profitable alternative to replacing traditional commercial panels. This study aimed to manufacture particleboards made with wood waste extracted from the stem of Theobroma cacao. The panels were bonded with different proportions of CS and urea–formaldehyde (UF) adhesives, and their physical–mechanical properties were determined. To manufacture the panels, cocoa wood wastes were mixed with the adhesive in ratios of 90:10, 70:30, and 50%:50% (CS/UF). Two control treatments were bonded with 100% of both adhesives. The resulting particleboards were employed as a reference to compare properties. The manufacturing process was carried out by cold pressing. Apparent density, water absorption, thickness swelling, and static bending strength were found for all panels. The data obtained were subjected to Levene’s homogeneity test, Shapiro–Wilk’s normality test, analysis of variance (ANOVA), and Tukey’s mean test. The results showed that the highest density value was 497.0 kg m⁻³, corresponding to the treatment composed of cocoa wood wastes bonded with 100% CS adhesive. The water absorption and thickness swelling results after a 24 h immersion showed that the panel formed using cocoa wood wastes and 100% UF had the lowest values, 22.1 and 11.2%. The highest bending strength value was 13.1 MPa for the experimental treatment composed of cocoa wood residue and 100% UF. However, this result did not differ statistically from the treatment (50–50). Therefore, cocoa wood waste combined with adhesive CS may be a sustainable alternative for producing particleboards. Full article

The continuous rise in global demand for wood products has led to an increase in prices and a surge in research into alternative resources. As a byproduct of the timber industry, bark has emerged as a promising supplement in particleboard (PB) production. However, its anatomical structure, the presence of extractives, and its inferior mechanical properties complicate the production process, which have not yet been fully overcome at a commercial scale. This study proposes a paradigm shift, advocating for separate and specialized bark constituent processing in a wet state. Three bark-based raw materials—namely, outer bark particles, bark fiber clumps, and bark fibers—were investigated under varying wood content scenarios. PBs with a target density of 0.7 g/cm³ and a thickness of 16 mm were produced using mixtures of these bark-based materials and wood particles in different ratios bonded with a urea–formaldehyde adhesive. The results demonstrated that these bark constituents exhibit distinct properties that can be optimized through tailored processing techniques. Compared to bark fibers, outer bark particles displayed about 40% lower water absorption and thickness swelling. However, bark fibers improved the internal bond by about 50% due to their favorable morphology compared to outer bark. These findings highlight the potential of bark as a valuable resource for particleboard production and pave the way for its efficient utilization through specialized processing strategies. Full article

Many factors (material properties, drill bit type and size, drill bit wear, drilling parameters used, and machine-tool characteristics) affect the efficiency of the drilling process, which could be quantified through the delamination factor, thrust force, and drilling torque. To find the optimal combination among the factors that affect the desired responses during drilling of wood-based composites, various modelling techniques could be applied. In this work, an artificial neural network (ANN) and response surface methodology (RSM) were applied to predict and optimize the delamination factor at the inlet and outlet, thrust force, and drilling torque during drilling of prelaminated particleboards, medium- density fiberboard (MDF), and plywood. The artificial neural networks were used to design four models—one for each analyzed response. The coefficient of determination (R²) during the validation phase of designed ANN models was among 0.39 and 0.96. The response surface methodology was involved to reveal the individual influence of analyzed factors on the drilling process and also to figure out the optimum combination of factors. The regression equations obtained an R² among 0.88 and 0.99. The material type affects mostly the delamination factor. The thrust force is mostly influenced by the drill type. The chipload has a significant effect on the drilling torque. A twist drill with a tip angle equal to 30° and a chipload of 0.1 mm/rev. could be used to efficiently drill the analyzed wood-based composites. Full article

Considerable efforts have been made to replace formaldehyde-containing adhesives in the manufacturing of wood products, particularly particleboard, with natural alternatives. One promising solution is the liquefaction of lignocellulosic materials such as wood using glycerol (C₃H₈O₃) under sulfuric acid catalysis (H₂SO₄). The aim of this study was to investigate the chemical composition and properties of spruce and oak biomass after liquefaction and to evaluate its potential as a formaldehyde-free adhesive substitute. All samples were liquefied at 150 °C for 120 min in five different wood–glycerol ratios (1:1 to 1:5). The liquefaction percentage, the insoluble residue, the dry matter and the hydroxyl (OH) number were determined as characteristic values for the polymer properties of the liquefied samples. The results showed the liquefaction percentage was up to 90% for spruce and oak. The insoluble residue ranged from 10 to 29% for spruce and from 10 to 22% for oak, the dry matter ranged from 54 to 70% for spruce and from 51 to 62% for oak, while the highest xydroxyl number was 570 mg KOH/g for spruce and 839 mg KOH/g for oak. Based on these results, liquefied wood was shown to be an effective natural alternative to synthetic resins in particleboard adhesives and a way to reduce formaldehyde emissions. This research not only supports environmentally sustainable practices but also paves the way for various bioproducts derived from liquefied biomass and points to future avenues for innovation and development in this area. Full article

The aim of the study was to identify limiting factors for reusing wood through the recycling of window frames by conducting research under fully controlled conditions. The research involved manufacturing new window frames, seasoning them, and then shredding them into wood particles to prepare a three-layer particleboard. The proportion of wood particles in recycling was 0, 5, 10, 25, 50, and 100 parts by weight of the manufactured particleboard. Mechanical property tests were conducted: modulus of elasticity (MOE) and modulus of rupture (MOR), internal bond (IB), screw withdrawal resistance (SWR), and physical properties: density profile (DP), thickness swelling (TS) after water immersion, water absorption (WA), as well as formaldehyde emission and total volatile organic compound (TVOCs) tests. The research indicates a significant potential for utilizing wood from this sector of the wood industry, particularly considering variants with a higher proportion of recycled wood. MOR and MOE results are most promising for variants above 50 parts by weight of recycled wood. Based on the results obtained, it is clear that the production process should be improved or the raw material modified to enhance the internal bonding of particleboard, as these results were the weakest. Thus, recycled wood from window joinery has the potential to be reincarnated as particleboard, which continues to be widely used in their production. Full article

This research focuses on producing particleboards from the biomass of plantation willow (Salix viminalis L.) and poplar (Populus spp.), aiming to explore their feasibility as sustainable materials for various applications. Fast-growing willow and poplar are known for their rapid growth and suitability for energy production. They present an intriguing alternative as raw materials with added value for particleboard manufacturing. This study investigates the selected mechanical and physical properties of the produced particleboards, considering parameters such as density profile, bending strength, modulus of elasticity, internal bond, water absorption, thickness swelling, and screw withdrawal resistance. The research results were also compared between different mass shares of willow and poplar particles in the particleboards. The results show that the panels produced entirely from the tested alternative raw materials had a modulus of rupture of 21.7 N mm⁻² compared to 14.6 N mm⁻² for the reference panels, with an internal bond of about 2.02 N mm⁻² compared to 0.65 N mm⁻² for the reference panels. The thickness swelling after 24 h of soaking was about 24.2% compared to 42.2% for reference panels. The findings underscore the promising potential of willow and poplar-based particleboards as eco-friendly alternatives in the construction and furniture industries, contributing to resource efficiency and carbon emission reduction efforts. Full article

Finishing coatings in the wood-based composites industry not only influence the final appearance of the product but also serve to protect against fungi and molds and reduce the release of harmful substances, particularly formaldehyde and volatile organic compounds (VOCs). Carbon-rich materials, such as those derived from birch bark extraction, specifically suberin acids, can fulfill this role. Previous research has demonstrated that adding suberin acid residues (SAR) at 20% and 50% by weight significantly enhances the gas barrier properties of surface-finishing materials based on poly(lactide) (PLA) and polycaprolactone (PCL), particularly in terms of total VOC (TVOC) and formaldehyde emissions. This study aims to explore whether these properties can be further improved through the incorporation of nano-zinc oxide (nano-ZnO). Previous research has shown that these nanoparticles possess strong resistance to biological factors and can positively affect the characteristics of nanofilms applied as surface protection. The study employed PLA and PCL finishing layers blended with SAR powder at 10% w/w and included 2% and 4% nano-zinc oxide nanoparticles. The resulting blends were milled to create a powder, which was subsequently pressed into 1 mm-thick films. These films were then applied to raw particleboard surfaces. TVOC and formaldehyde emission tests were conducted. Additionally, the fungal resistance of the coated surfaces was assessed. The results showed that PLA/SAR and PCL/SAR composites with the addition of nano-zinc oxide nanoparticles exhibited significantly improved barrier properties, offering a promising avenue for developing biodegradable, formaldehyde-free coatings with enhanced features in the furniture industry. Furthermore, by utilizing SAR as a post-extraction residue, this project aligns perfectly with the concept of upcycling. Full article

The disposal of wood waste at facilities for incineration in Sweden is the only applied management practice today. Energy production from biomass has gained attention for its potential to recover energy and reduce greenhouse gas emissions. However, besides being a valuable source for energy generation, wood waste can be effectively recycled into new products. Specifically, recycling wood waste into particleboard is the widely practiced method in Europe, while its benefits have not been explored in the country so far. The objective of this study is to assess the environmental, social, and economic sustainability of producing particleboard and generating energy from wood waste in Sweden. This research investigates four alternative systems for wood waste disposal. The first system involves the production of heat, the second system involves heat and power by wood waste, while the third and the fourth systems, in addition to energy recovery, include partial recycling of wood waste in particleboard production. A life cycle sustainability assessment covering all three pillars (environment, social, and economic) of sustainability was conducted to compare these systems. The results show that adding recycling schemes to incineration in wood waste management practices strengthens the sustainability for all three aspects, and hence, these management methods can be considered as complementary methods rather than competing methods. When all sustainability categories are considered, alternative three (heat recovery and recycling) comes forward as the best option in 11 out of 16 impact categories. Full article

Various methods for the effective modification of urea–formaldehyde (UF) adhesives, aimed at enhancing the performance of wood-based materials, have been continually explored worldwide. The aim of this work was to investigate and evaluate the effect of introducing small amounts (0.25–1.5%) of activated carbon from coconut shells (ACCS) in UF adhesive on the properties of particleboard. The performed investigations of the adhesive mixture’s properties showed an increase in both viscosity and reactivity. Moreover, the use of loadings of 0.75% and 1% had a positive effect on mechanical properties such as bending strength, modulus of elasticity, and internal bond. In these variants, a delay in the degradation of the adhesive bonds by water was also observed, as indicated by the lower thickness swelling values measured after 2 h. However, under long-term exposure to water, the modification had no considerable effect on the dimensional stability of the boards. Markedly, the addition of 1 and 1.5% of ACCS resulted in a reduction in formaldehyde content, which can be attributed to the excellent adsorption capacity of activated carbon. Overall, a loading of 1% was found to be optimal, resulting in improved strength, enhanced water resistance, and reduced formaldehyde content. Full article

In this study, we used a self-neutralizing system to counteract too acidic a pH, unsuitable for wood adhesives, and tested it on MUF resins augmented by the addition of citric acid or other organic acids, based on the addition of small percentages of hexamine or another suitable organic base to form an acid–base buffer. In this manner, the pH of the adhesive was maintained above the minimum allowed value of 4, and the strength results of wood particleboard and plywood bonded with this adhesive system increased due to the additional cross-linking imparted by the citric acid. Thus, the wood constituents at the wood/adhesive interface were not damaged/degraded by too low a pH, thus avoiding longer-term service failure of the bonded joints. The addition of the buffering system increased the strength of the bondline in both the plywood and particleboard, both when dry and after hot water and boiling water tests. The IB strength of the particleboard was then increased by 15–17% when dry but by 82% after boiling. For the plywood, the shear strengths when dry and after 3 h in hot water at 63 °C were, respectively, 37% and 90% higher than for the control. The improvement in the bonded panel strength is ascribed to multiple reasons: (i) the slower, more regular cross-linking rate due to the action of the buffer; (ii) the shift in the polycondensation–degradation equilibrium to the left induced by the higher pH and the long-term stability of the organic buffer; (iii) the additional cross-linking by citric acid of some of the MUF resin amine groups; (iv) the already known direct linking of citric acid with the carbohydrates and lignin constituents at the interface of the wood substrate; and (v) the likely covalent linking to the interfacial wood constituents of the prelinked MUF–citric acid resin by some of the unreacted citric acid carboxyl groups. Full article

Global poultry waste production is substantial, with billions of poultry raised annually for meat and egg production, resulting in significant feather waste. Conventional poultry waste disposal methods are restricted due to environmental concerns. Meanwhile, wood-composite panel industries face raw material shortages, emphasizing the need for sustainable, renewable fiber sources. In this study, in the core layer of panels, wood particles were replaced with 5 wt% clean duck feathers without pretreatment to take advantage of feather attributes like hydrophobicity, thermal insulation, and sound damping as an alternative construction material. Three adhesives—urea-formaldehyde (UF), polymeric 4,4′-diphenylmethane diisocyanate (pMDI), and polyvinyl acetate (PVAc)—were examined for resin–feather compatibility. The control panels in this study were identical but wood was not replaced with feathers. The results revealed that wood–feather particleboard with pMDI and PVAc resins meets the requirements of the relevant standard for P2 boards (where applicable) concerning their modulus of rupture (MOR: 11 N·mm⁻²), modulus of elasticity (MOE: 1600 N·mm⁻²), internal bond (IB: 0.35 N·mm⁻²), and screw withdrawal resistance (SWR). However, those produced with UF resin did not meet the standards for IB and MOE. Furthermore, the physical properties showed similar water resistance and thickness swelling to control panels with pMDI. Notably, substituting 5 wt% wood with feathers improved thermal insulation by approximately 10% for UF and pMDI resins. Additionally, particleboard with feathers demonstrated improved sound absorption at high frequencies, ranging from 2500 to 500 Hz, particularly with pMDI resin, approaching Class B classification according to EN ISO 11654:1997. This study identifies the higher compatibility of pMDI over PVAc and UF adhesives for feather-based composite materials in construction applications. Full article