Search Results (41)

Human activities undoubtedly increase greenhouse gases (GHG), negatively influencing global climate change. The building and construction sector uses at least 40% of the total energy consumption and produces the same percentage of GHG emissions. Therefore, the development of sustainable building materials is a crucial key factor for environmental protection. The study contributes to the development of bio-based façade materials using available raw biomass like wheat straw, grey alder, and softwood (a mix of spruce and pine), to promote reduced emissions of CO₂. Two technologies were used to produce high-density particleboards based on (1) steam explosion treatment and (2) the addition of bio-based suberinic acids as a binder. In addition to the biomass species and board type, the influence of conventional and mold hot-pressing was investigated on produced board properties: density, thickness swelling, modules of rupture and elasticity in bending, and internal bonding. The obtained particleboards demonstrate significant differences in terms of the tested properties depending on all variable factors. The best performance, in terms of physical–mechanical properties, was achieved by the conventionally hot-pressed board of steam-exploded grey alder particles, being influenced by the highest density (1380 kg/m³). Mold hot-pressing in most cases resulted in decreased performance of obtained boards. Full article

This study explores the lamination performance of wood-plastic composite boards designed for indoor decoration, aiming to enhance adhesion between a wood fiber/high-density polyethylene (HDPE) composite board and poplar wood veneer by incorporating fabrics (canvas or polyester fibers) as an intermediate layer. Traditional adhesives, such as polyvinyl acetate (PVAc) and isocyanate, were utilized to create decorative panels with a multi-interface sandwich structure. The impacts of factors such as the hot-pressing temperature, wood fiber content in the substrate, and fabric type on the performance of the panels were systematically investigated. The results indicated that the hot-pressing temperature of the substrate had minimal effect on the lamination performance. Panels that used canvas fabric as the intermediate layer and bonded with a mixed adhesive of PVAc and isocyanate exhibited superior surface bonding strength (2.76 MPa), bending properties (strength = 49.21 MPa; modulus = 3.92 MPa), and tensile properties (strength = 31.62 MPa; modulus = 1.51 GPa). The enhanced performance was attributed to the covalent bonding formed by isocyanate with canvas fabric, polyester fibers, and wood veneer, whereas PVAc primarily established physical bonds through penetration. 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 construction sector’s increasing eco-consciousness is driving the need for higher-performance wood-based engineered products from underutilized timber resources, such as small-diameter trees from hazardous fuel treatments of our forests. Strand-based products, including oriented strand board (OSB) and lumber (OSL), are widely used. However, hot-pressing during their manufacturing generates approximately 10% waste, which includes a substantial amount of resinated strands that are landfilled. The huge potential of using strand-based products has led to many studies and growing interest in strand-based three-dimensional sandwich panels that can be used as wall, floor, or roofing panels. As the market grows, understanding the recyclability of these resinated strands becomes crucial. This study investigates the feasibility of using re-resinated waste strands that were collected during lab-scale production of strand-based panels. Results demonstrate significant improvements in dimensional stability, mechanical properties, and fire resistance. Specifically, recycling increased internal bond strength, flexural strength, time to ignition, time to flameout, mass loss, and time to peak heat release rate by 107%, 44%, 58%, 35%, 51%, and 27%, respectively, and helped decrease water absorption and thickness swell by 51% and 58%, respectively. Full article

The development of wheat straw boards utilizing intrinsic bonding mechanisms not only facilitates the high-value utilization of agricultural solid waste but also diminishes the reliance on synthetic adhesives. In this study, using wheat straw as the primary substrate, we investigated the effects of mechanical smashing combined with pretreatment using inorganic acids or alkalis on the properties of hot-pressed boards, as well as the relationship between the properties of hot-pressed boards and the physical properties and chemical composition of wheat straw raw materials. These selective pretreatments effectively degraded lignin, hemicellulose, and other components, thereby promoting fiber reorientation and resulting in a denser microstructure with improved self-bonding capabilities. The optimal board was fabricated with a granularity of 0.3 mm and underwent alkali pretreatment, achieving a tensile strength of 11.564 MPa, an internal bonding strength of 0.556 MPa, and bending strength and modulus of 24.306 MPa and 2.766 GPa, respectively. These findings have significant implications for advancing manufacturing processes and conceptualizing binder-free boards derived from agricultural residues. Full article

The hot pressing process for 100% coriander-based fiberboards was optimized using an induction RocTool system, which offers rapid mold heating and cooling. The fiberboards were made using deoiled press cake as a protein binder and extrusion-refined straw as reinforcement. Doehlert’s experimental design was used to evaluate the influence of pressure (10–50 MPa), molding time (60–300 s), and mold temperature (155–205 °C) on fiberboard properties, energy consumption, cost, and environmental impact. The results showed that the RocTool device allows for better temperature control during shaping throughout the mold, resulting in mechanical properties that are both more homogeneous across the entire surface of the panel and, more importantly, substantially improved. Using the isoresponse curves, the optimal hot pressing conditions were 35 MPa, 300 s, and 205 °C, corresponding to a 40.6 MPa flexural strength. However, it was observed that to achieve an MDF-like fiberboard with minimal production costs, much less restrictive molding conditions were sufficient, i.e., 32.5 MPa, 170 s, and 160 °C. The study revealed that maximum thermopressing conditions emitted 3.87 kg of CO_2 eq., while conditions leading to the MDF-like board reduced emissions to 1.45 kg CO_2 eq., resulting in a more environmentally friendly material. Full article

Studies on self-binding hot-pressed fiberboards using agricultural byproducts aim to identify alternatives to scarce wood resources. Particle size and mixture significantly impact strength, although direct comparisons are difficult due to differences in study methods. We evaluated fiberboards made from the two perennial biomass crops Miscanthus and Paulownia and compared them to Picea (spruce), using five distinct particle size blends prepared from milled and sieved particles, respectively. The boards were evaluated for their modulus of elasticity, modulus of rupture, reaction to fire, water absorption, and thickness swelling. All specimens exhibited normal ignitability, as defined by Euroclass E according to EN13501-1. The results indicate that mechanical performance improves with increasing density, which correlates with higher proportions of finer particles. Notably, the finer Miscanthus blends and all Paulownia samples met the modulus of elasticity requirements of EN 622. Full article

In the hot press process of high-performance bamboo-based fiber composites, there is a highly nonlinear relationship between the production parameters of hot press and the quality parameters of the finished boards. Consequently, it is challenging to accurately predict the quality of the boards based on the given production parameters, and it is equally difficult to preset the production parameters to achieve the desired board quality. The current approach relies on manual experience, which may result in subpar board quality and material waste. To address these issues, this paper proposes a bi-directional prediction model based on cHGWO-SCA-SVR, using the collaboration-based hybrid GWO-SCA optimizer to optimize the relevant parameters of the SVR, and then accurately predicting the production parameters and the quality of the finished boards in both directions. Finally the cHGWO-SCA-SVR prediction model achieves an average ${\mathrm{R}}^2$ of 0.9591 for the forward prediction model and lower MAE and MSE values compared to other models; for the reverse prediction model, it attains an average ${\mathrm{R}}^2$ of 0.9553 and lower MAE and MSE values compared to other models. The results demonstrate the superiority of the cHGWO-SCA-SVR prediction model in comparison with other existing models, proving its significance in guiding the production of high-performance bamboo-based fiber composites by hot compression. Full article

Due to their outstanding properties, bamboo-based fiber composites are gaining significant traction in the fields of construction and decoration. Among the crucial process steps in their production, hot pressing stands out as a pivotal one. Temperature, being a key parameter in hot pressing, and its stability of control exert a profound impact on the finished mechanical properties and associated indices of bamboo-based fiber composites. In this investigation, we introduce an active disturbance rejection control (ADRC) methodology specifically tailored for the hot-pressing temperature of bamboo-based fiber composites. A mathematical model encompassing the motor, steam regulating valve, and, ultimately, the hot-pressing temperature is formulated, with the transfer functions at each level being precisely determined through parameter identification techniques. The simulation outcomes reveal that in the absence of signal interference, sinusoidal signal interference, or random signal interference, the ADRC method outperforms the traditional PID algorithm in the realm of hot-pressing temperature control for bamboo-based fiber composites. This approach effectively reduces the temperature fluctuations of the PID algorithm, thereby averting issues such as premature curing or board bursting. In summary, this study holds significant implications for enhancing the mechanical properties of bamboo-based fiber composites. Full article

Repurposing agricultural and forestry by-products not only is beneficial for the environment but also follows the principles of the circular economy. In southeastern Spain, the Canary Island palm tree (Phoenix canariensis W.) is widely used in urban landscapes. Plantations affected by the red weevil, a pest, generate an abundance of plant waste that must be crushed and transferred to authorized landfills. The aim of this study was to manufacture boards using particles from trunks of the Canary Island palm tree without adding any binders in order to obtain an ecological and fire-resistant product. In order to manufacture the boards, three particle sizes (<0.25, 0.25–1, and 1–2 mm), a temperature of 110 °C, a pressure of 2.6 MPa, and a pressing time of 7 min were used. The boards were pressed in a hot plate press for 7 min up to four times (7 min, 7 + 7 min, 7 + 7 + 7 min, and 7 + 7 + 7 + 7 min). The resulting boards showed good thermal performance, and the board´s reaction-to-fire performance was classified as Bd0 (an Fs value of 70.3 mm). This study also showed that boards with a particle size smaller than 0.25 mm that underwent four pressing cycles of 7 min each in the press can be categorized as grade P2 according to the European Standards (MOR of 20 N/mm², MOE of 2589.8 N/mm², and IB of 0.74 N/mm²). Therefore, these manufactured particleboards could be used as a flame-retardant material for the interior enclosures of buildings (vertical and horizontal) without the need for coatings. Full article

To further improve the manufacturing process and product performance of decorated bamboo filament board, the Box–Behnken response surface analysis method was used to analyze the correlation between the hot-pressing parameters and surface bonding strength, and the optimal process optimization parameters were obtained. In addition, the wettability and color of each group of samples were tested. The results show that the optimum process parameters of decorated bamboo filament boards were 130 °C, 165 s and 2.00 MPa, and the surface bonding strength was 1.58 MPa. The relative error between the measured value and the predicted value was less than 5%. The contact angle of the bamboo filament after hot pressing was higher than without hot pressing. However, there was no correlation between wettability and the hot-pressing parameters. There was no effect on the change in bamboo surface color. This indicates that the temperature range selected in this study meets the requirements of surface color control in production. Full article

The production of wheat straw waste board materials encounters challenges, including inadequate inherent adhesiveness and the utilization of environmentally harmful adhesives. Employing a hot-pressed method for converting wheat straw into board materials represents a positive stride towards the resourceful utilization of agricultural wastes. This study primarily focuses on examining the influence of hot-pressing process conditions on the mechanical properties of wheat straw board materials pretreated with dilute acid. Additionally, it assesses the necessity of dilute acid treatment and optimizes the hot-pressing conditions to achieve optimal results at 15 MPa, 2 h, and 160 °C. Furthermore, a comprehensive process is developed for preparing wheat straw hot-pressed board materials by combining dilute acid pretreatment with surface modification treatments, such as glutaraldehyde, citric acid, and rosin. Finally, a thorough characterization of the mechanical properties of the prepared board materials is conducted. The results indicate a substantial improvement in tensile strength across all modified wheat straw board materials compared to untreated ones. Notably, boards treated with glutaraldehyde exhibited the most significant enhancement, achieving a tensile strength of 463 kPa, bending strength of 833 kPa, and a water absorption rate of 14.14%. This study demonstrates that combining dilute acid pretreatment with surface modification treatments effectively enhances the performance of wheat straw board materials, offering a sustainable alternative to traditional wood-based board materials. Full article

Wood chipboard, common in interior spaces for applications ranging from furniture to decorative panelling, often falls short due to the presence of toxic adhesives, posing risks to both human health and the environment. This research delves into the potential transformation of wood chipboard into a 100% bio-based product. Previous research has shown the possibility of the partial replacement of petrochemical-based adhesives with bio-based adhesives. Hence, previous results do not reach the policy ambitions of the Green Deal of making the Green Transition to a bio-based economy. For chipboard production, logging residues from Latvian State Forests were systematically gathered within two months post-logging, comprising primarily Picea abies and Pinus sylvestris biomass, including branches, needles, bark, and various particles. A custom chipper and Vibrotehnik PM-120 hammer mill were employed for particle size separation into three fractions via sieving: <2.8 mm, 2.8–8 mm, and 8.0–10.0 mm, and combined with binders and hot-pressed into board samples. As a result, particle boards containing 100% bio-based carbon were achieved, demonstrating the possibility of excluding petroleum adhesives from chipboard production, paving the way for new research exploring bio-based binders and conifer bark. Full article

Currently, the predominant thermal insulation materials in the construction industry are primarily derived from inorganic sources. While these materials demonstrate commendable thermal insulation capabilities, their widespread use raises significant environmental concerns. The utilization of wood fiber materials presents a promising solution to mitigate these drawbacks. This study focuses on the fabrication of biodegradable fiber insulation board (BFIB) using camphor branches. The manufacturing process avoids the use of chemical additives, employing a physical method that utilizes hot pressing and relies on the formation of intermolecular hydrogen and hydroxide bonds between the fibers. The study evaluates the influence of applied pressure on the properties of BFIB. SEM images reveal that, with an increase in applied pressure, the fibers exhibit a more regular pattern, subsequently enhancing the mechanical properties, hygric behavior, and fire resistance properties of BFIB. As an environmentally friendly and renewable material, BFIB holds the potential to substitute conventional insulation materials. It is particularly intriguing for energy-saving purposes when applied as building insulation for walls or ceilings. Full article

This study focuses on the increased risk of high heat release and asphyxiation (toxic gas poisoning) in the event of a fire involving polyurethane (PU)- and MDF-based building materials, which are commonly used in buildings. Among them, polyurethane (PU) building materials are very commonly used in buildings, except in Europe and some other countries, due to their excellent thermal insulation performance. Still, problems of short-term heat release and the spread of toxic gases in the event of a fire continue to occur. To overcome these problems, researchers are actively working on introducing various flame retardants into building materials. Therefore, in this study, we produced a laboratory-sized (500 mm × 500 mm) plate-like flame-retardant board that can be utilized as a building material with a lower heat release rate and a lower toxicity index. The material was made by mixing expanded graphite and ceramic binder as flame retardants in a material that is formulated based on the cellulose of waste paper, replacing the existing building materials with a hot-press method. According to the ISO-5660-1 test on the heat release rate of the plate-like flame-retardant board, the Total Heat Release (THR) value was 2.9 (MJ/m²) for 10 min, showing an effect of reducing the THR value by 36.3 (MJ/m²) compared to the THR value of 39.2 (MJ/m²) of the specimen made using only paper. In addition, the toxicity index of the flame-retardant board was checked through the NES (Naval Engineering Standards)-713 test. As a result, the test specimen showed a toxicity index of 0.7, which is 2.4 lower than the toxicity index of 3.1 of MDF, which is utilized as a conventional building material. Based on the results of this study, the cellulose fire-retardant board showed the effect of reducing the heat release rate and toxicity index of building materials in a building fire, which reduces the risk of rapid heat spread and smoke toxicity. This has the potential to improve the evacuation time (A-SET) of evacuees in fires. It is also important to show that recycling waste paper and utilizing it as the main material for building materials can be an alternative in terms of sustainable development. Full article