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The pulp and paper industry generates vast quantities of paper sludge, posing significant environmental challenges due to its disposal in landfills or incineration. This study explores the potential of valorizing paper sludge by incorporating it into particleboard production. It aims to optimize sludge content and particle size to enhance board properties—a novel approach to waste management in the wood composites industry. Through systematic variation of sludge content (0–25%) and particle size (< 0.5 to > 2 mm), we assessed the mechanical and physical properties such as internal bond strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA), and thickness swelling (TS). The findings indicate that incorporating paper sludge at moderate levels (5–15%) with optimized particle sizes (< 1 mm) significantly improves the mechanical properties of the particleboard, including increased IB, MOR, and MOE while reducing WA and TS. Principal Component Analysis (PCA) further supported these results, revealing that higher-density boards with enhanced mechanical properties absorb less water, highlighting the interrelationship between structural integrity and moisture resistance. The PCA also identified thickness swelling as an independent factor, suggesting that while mechanical properties can be optimized, additional strategies are needed to control swelling. In conclusion, this study demonstrates that up to 15% paper sludge can be effectively used in particleboard production without compromising quality, provided particle size is carefully controlled. This approach not only offers a sustainable solution for managing paper sludge but also contributes to the development of eco-friendly composite materials, aligning with circular economy principles. [ABSTRACT FROM AUTHOR]

The effect of shredded waste office paper was considered when producing one-layered particleboard. Five different mixing ratios of shredded waste office paper/wood particles were used (0/100, 25/75, 50/50, 75/25, and 100/0) and two amounts of urea formaldehyde (UF) resin (10% and 15%). The boards were tested for their physical and mechanical properties, including modulus of elasticity (MOE), bending strength (MOR), and internal bond (IB) strength, in accordance with the European Norm (EN) standards. All properties of the boards were found to be improved via increasing the resin content. The 15% UF-bonded board with 100% wood particles had the highest MOR, whereas the board containing 100% wastepaper for 15% UF had the highest MOE. However, there was no statistical difference between the board types. Although increasing wastepaper content in the board negatively affected the IB, the usage of wastepaper up to 25% was shown to be acceptable as a raw material in the production of particleboard. None of the prepared boards met the EN 312 (1999) requirements for thickness swelling. The boards made from shredded waste office paper were more suitable for dry and indoor use. [ABSTRACT FROM AUTHOR]

Under this study, the particle boards of lops and tops of poplar were prepared using urea formaldehyde resin with 110 °C pressing temperature. One set of particle boards was kept as control particle boards, and remaining boards were treated with five different combinations of fire retardant (FR) chemicals at 10% and 20% conc. by dipping method for 15 min and 30 min duration. The prepared control particle boards as well as FR treated boards were tested in accordance with IS 3087, IS 2380 and IS 5509 for their various properties, viz. modulus of rupture (MoR), modulus of elasticity (MoE), internal bond strength (IBS), time taken under rate of burning test (RBT), flammability test (FT) and flame penetration test (FPT). It was found that particle board treated at both concentration (10%, 20%) and both duration (15 min, 30 min) of dipping with all five compositions passed the mechanical test, viz. MoR, MoE and IBS whereas particle board treated at lower concentration (10%) and both duration (15 min, 30 min) of dipping with all five compositions do not pass the FR properties, viz. time taken under RBT, FT and FPT as per relevant IS specifications. The particle board treated at higher concentration (20%) and both duration (15 min, 30 min) of dipping with all five compositions passed the FR properties, viz. time taken under RBT, FT and FPT as per relevant IS specifications. However, at higher concentration (20%) and higher duration (30 min) of dipping the IBS reduces significantly but still all mechanical properties, viz. MoR, MoE and even IBS meet as per relevant IS specifications. [ABSTRACT FROM AUTHOR]

The valorization of bioeconomy by-products holds immense significance in achieving sustainability goals and fostering resource efficiency, not only to reduce the amount of waste generated but also to significantly decrease the carbon footprint associated with several industrial fields, by promoting circular economy. The wine industry is not only one of the major contributors for world’s economy but also a great producer of by-products, with no valorization process associated. Grape stalks are a great source of chemical molecules, as polyphenols, that can be applied in the production of bio-adhesives. In the present work, grape stalk particles were used as raw material to obtain a highly rich extract with bonding properties through solid/liquid extraction. Different extraction agents were tested (water, NaOH, and Na2CO3) at varied concentrations (0.1%, 0.5%, and 1.0%, respectively). Additionally, extracts were chemically characterized, and the bonding capacity was also evaluated. Using NaOH 1.0%, an extraction efficiency of 8.9% and a total content of polyphenols of 1.4% were achieved. Moreover, all extracts presented an interesting bonding capacity (>1.0 MPa) by hot-press at 120°C for 120 s. The composite panel produced using grape stalk adhesive and vine strain particles fulfills the requirements for type P1 particleboards in terms of internal bond strength, reaching 0.66 MPa. The mechanical and wettability properties of composite material allow foreseeing a promising application in the food packaging industry. [ABSTRACT FROM AUTHOR]

In this study, under laboratory conditions, hazelnut husk and astragalus plant were mixed separately into black pine wood chips, and multi-purpose boards were produced from the obtained chips with urea formaldehyde glue. After the hazelnut husk and astragalus plant were dried and ground, they were added to the chip and glue mixture in certain proportions. Hazelnut husk mixture ratios were applied as 100 %; 0 %, 75 %; 25 %, 50 %; 50 %, 25 %; 75 %, 0 %; 100 % to black pine wood chip in the particle board mixture. These ratios were made in the same way for the astragalus plant. From these mixtures, chipboard blanks of 16 mm thickness and densities between 0,68 g/cm3 and 0,72 g/cm3 were produced. Density, moisture content, thickness increase, water intake, bending strength, modulus of elasticity in bending and tensile strength perpendicular to the surface were tested in physical and mechanical experiments. According to the results obtained, as the participation rate of hazelnut shells and astragalus increased, the durability properties of the panels decreased. At the same time, it shows that the technological properties of the panels produced by adding up to 25 % astragalus plant and hazelnut shells to the mixture comply with the standards.

While most of the influences on the mechanical properties of particleboard appear to have been investigated, there is a lack of knowledge about the influence of particle size or particle dimensions due to the absence of a suitable particle measuring technique. The introduction of laser-based 3D scanning technology makes it possible to automatically determine the dimensions, surface area, and volume of particles. In this study, the influence of particle size on the mechanical properties of particleboards was investigated. To isolate potentially overlapping influences, single-layer particleboards with a uniform density profile were produced and analyzed. The amount of adhesive specific to the surface of the (fine) face layer particles and (coarse) core layer particles was adjusted utilizing 3D scanning of the surface areas to ensure comparability despite changes in particle size. It was found that with increasing particle size, the modulus of rupture (MOR) and modulus of elasticity (MOE) increase, while the internal bond strength (IB) decreases. It is considered whether these effects result from a particle-size-dependent orientation of the particles in the board. Furthermore, it is shown that all the aforementioned properties increase with increasing surface-specific adhesive amounts. Examples are provided to demonstrate how such fundamental relationships can be utilized to enhance the particleboard production process. [ABSTRACT FROM AUTHOR]

A novel conductive composite material was developed using woven carbon nets. For this purpose, carbon nets with different mesh sizes of 25, 100, 225, and 400 mm2 were woven, using two different carbon yarns with widths of 2 and 0.5 mm. The woven carbon nets were used before and after the core layer formation during mat forming of the particleboard. It was found that the insertion of carbon nets into the panel structure not only transforms insulated particleboard into a highly conductive composite but also significantly improves the flexural properties of the composite. However, the internal bond strength and physical properties of the composites were negatively affected by the presence of carbon nets in the panel structure, although their values were still above the minimum requirements of the standard values. Increasing the mesh area of the carbon nets and using thinner carbon yarns to weave the nets had a negative effect on the electrical and mechanical properties of the composites. In addition, a demonstration object was made of conductive composites to integrate lighting and a smartphone charging port into the object and prove the applicability of the developed composites for the furniture industry. Highlights: Composites with carbon nets with smaller mesh area showed higher conductivity.The smaller the width of the carbon yarn, the higher the electrical resistance.The carbon net in the composites led to a decrease in internal bond strength.The carbon nets improved the flexural properties of the composites.Thickness swelling was significantly reduced by the use of carbon nets. [ABSTRACT FROM AUTHOR]

Brewer's spent grain (BSG) is the main solid waste generated in beer production and primarily consists of barley malt husks. Based on the active promotion of circular economy practices aimed at recycling food industry by-products, this study assessed for the first time the production of particleboards based on BSG as the sole source of lignocellulosic material and natural adhesive without the use of additives or other substrates. In order to achieve particleboards from entirely sustainable sources, BSG particles have to self-bind by thermo-compression with water. In this context, the aim of this study is to assess the effects of pressing temperatures and particle size on properties such as modulus of elasticity, modulus of rupture, internal bond, thickness swelling, and water absorption. The performance of binderless boards was compared with that of a control panel (control) using BSG combined with phenolic resin. Processing conditions were selected to produce boards with a target density of 1000 kg/m³ and a thickness of 5 mm. To confirm the efficiency of the self-adhesion process, scanning electron microscopy was used to examine the boards. The processes of self-adhesion and particle-to-particle contact were facilitated at a pressing temperature of 170 °C and a particle size range of 200–2380 µm (ground BSG), resulting in improved flexural properties and enhanced water resistance. The properties of BSG-based binderless boards were comparable to those reported for other biomass residues, suggesting that they might be used in non-structural applications, such as interior decoration. [ABSTRACT FROM AUTHOR]

This study investigated Australian hemp hurd (Cannabis sativa L., "Frog One") as a lignocellulosic raw material for ultra‐low‐density hemp particleboard (ULHPB) with densities ranging from 213 to 309 kg/m3. The hurd was first milled and fractionated into three particle size categories, that is, fine (F), medium (M), and coarse (C). Twelve unique ULHPB variants were then fabricated comprising varying particle loadings from four particle size mixes, that is, 100% C, 100% M, 50%/50% CM, 25%/50%/25% CMF, and adhesive contents of bio‐epoxy (EPX), phenol resorcinol formaldehyde (PRF), and emulsifiable methylene diphenyl diisocyanate (MDI), respectively. The panel assessments, conducted in accordance with the Australian reconstituted wood‐based panels standard AS/NZS 1859.1 (2017), revealed a significant effect of particle dimension on most physico‐mechanical properties. Furthermore, the resination method and pressing temperature controlled post‐cure panel expansion and additional panel characteristics. Notably, MDI‐ULHPB exhibited drastically different behavior and properties compared to EPX and PRF equivalents, demonstrating greater bending strength, stiffness, screw withdrawal strength, and dimensional stability. Importantly, all MDI variants conformed to the 15% thickness swelling limit for moisture resistant particleboard. Surface lamination of MDI‐bonded ULHPB with sheets of aluminum, Masonite, and Kraft liner significantly improved the inherently low flexural properties, suggesting the potential suitability of ULHPB as a core layer in lightweight sandwich composite panels. The integration of agricultural by‐products, such as hemp hurd, into engineered building materials presents a promising opportunity to mitigate the depletion of finite timber resources and aligns well with circular economy principles. Highlights: Utilizing agricultural residue as sustainable raw material in building products.Hemp hurd enables ultra‐low‐density particleboard with thermosetting resins.Coarse particle size mix enhances mechanical performance in panels.Panel characteristics controlled by resination method and pressing temperature.Lamination enhances functionality of lightweight hemp hurd sandwich panel. [ABSTRACT FROM AUTHOR]

Nowadays, the particleboard industry cannot meet the market's demand. Therefore, filler materials have started to be used both to conserve raw materials and to enable the use of wood-based boards in different areas. This study investigates the effects of incorporating different ratios of activated carbon (0%, 1.5%, 4.5%, 7.5%) on the properties of particleboards. The physical properties were examined, including density, moisture content, thickness swelling, and water absorption. The results reveal that the density increased with increasing activated carbon content while the moisture content decreased, indicating improved dimensional stability and water resistance. Additionally, the color properties were influenced by activated carbon, leading to a darker appearance with decreased lightness and yellow-blue components. The mechanical properties, such as internal bond strength, modulus of rupture, and modulus of elasticity, showed significant enhancements with the addition of activated carbon, indicating improved bonding and increased strength. Moreover, the thermal conductivity decreased with increasing activated carbon content and improved insulation performance. Scanning electron microscope analysis confirmed the uniform distribution of activated carbon within the particleboard matrix, without agglomeration, positively impacting the mechanical performance. According to the thermogravimetric analysis results, the addition of activated carbon led to a decrease of up to 6.15% in mass loss compared to the control group. The incorporation of activated carbon at a ratio of 4.5% in particleboards confers notable enhancement to their physical, mechanical, and thermal characteristics. These findings contribute to understanding the potential benefits and considerations of using activated carbon as an additive in particleboard production. [ABSTRACT FROM AUTHOR]

The mechanical properties and termite and decay resistance performance of wood-based panel used in wooden houses were evaluated. The physical and mechanical properties, along with the resistance levels, of commonly used wood-based panels, including oriented strand board, structural particleboard, and particleboard for use in interior, were compared. The structural particleboard complied with the physical, mechanical, and formaldehyde emission standards of the International Organization for Standardization and Japanese Industrial Standard, surpassing the requirements for oriented strand board. The structural particleboard exhibited excellent water resistance and a consistent performance. Decay tests classified the particleboard and structural particleboard as "Resistant," with mass losses of 7.82 to 12.72% (white rot) and 14.69 to 16.55% (brown rot). Pine (Pinus densiflora) and oriented strand board exhibited no decay resistance, with mass losses exceeding 45%. The particleboard and structural particleboard demonstrated superior termite resistance, resulting in 100% termite mortality in three days without chemical treatment. The structural particleboard exhibited excellent water, decay, and termite resistance, which can be an advantage in wooden-house construction in terms of maintenance. [ABSTRACT FROM AUTHOR]

Nowadays, a significant increase in interest in renewable energy sources can be observed. Wind farms have been one of the solutions representing this trend for many years. One of the important elements of windmills is the blades. The data indicate that what to do with the blades after their use is a global problem, and so it is important to find a way to recycle them. Hence, this work aimed to use these blades in the production of wood-based materials. Two fractions of a fragmented blade were used for the tests: a small one and large one. Boards characterized by densities of 650 kg/m3 and 700 kg/m3 were produced, in which the assumed substitution of the wood material with a polymer was 20% or 40%. Mechanical properties such as bending strength (MOR), modulus of elasticity (MOE), and internal bond strength (IB) were investigated. The 2S65 variant achieved the highest static bending strength and a modulus of elasticity of 2625 N/mm2. The second best result was noted for the 4S65 variant, which was significantly different from the 2S65 variant. In the case of the variants with a density of 700 kg/m3, no significant differences were found and their results were significantly lower. Moreover, research on thickness swelling (TS) after 24 h of immersion and water absorption (WA) were also conducted. The obtained results indicate that the manufactured boards are characterized by good physical and mechanical properties. [ABSTRACT FROM AUTHOR]

Biobased particleboards from rice husk (RH) and soybean protein concentrate (SPC) based adhesive were evaluated over 180 days under indoor conditions. Two alternatives were evaluated: the incorporation of carvacrol to the SPC based adhesive, as a natural preservative, and the coating of the RH-SPC based particleboards with a polyurethane lacquer. Coated panels showed the lowest thickness swelling and water absorption at 2 and 24 h of immersion. The modulus of rupture (MOR) increased for the coated panels, while the elasticity modulus (MOE) was the same for all formulations. MOR and MOE obtained for all particleboards evaluated over time met the requirements established by ANSI Standard A208.1 along the 180 days of study. Results showed that particleboard have good physical and mechanical stability under indoor environmental conditions, presenting a good performance at least up to six months. [ABSTRACT FROM AUTHOR]

In the present work, wooden furniture wastes were used as pore-forming agents for the manufacture of fired clay bricks. The main objectives of this study are (i) to investigate the impact of adding wooden furniture wastes into the clay body on the mechanical properties and (ii) to identify gas emissions during the firing process. For this purpose, five categories of wooden furniture wastes were selected and mixed, after grinding, with raw clay materials. The samples were extruded into green bodies and then fired at 950 °C. The influence of the type and amount of the addition of pore-forming agents (5 or 10 wt. %) on the mechanical properties of the fired samples was studied and compared to values obtained for lightweight bricks. Results showed that the formation of macropores slightly decreased the mechanical strength. The analysis of the chemical composition of the gas released during the firing process was carried out. Results were compared to literature for gases emitted in the manufacturing of porous masonry brick, using sawdust as a pore-forming agent. It was found that the gases released after the combustion of clay incorporating particle board wood wastes (PP) are not higher in content than those from the case of masonry brick using sawdust. [ABSTRACT FROM AUTHOR]

Paulownia wood has raised high attention due to its rapid growth and fire resistance. The number of plantations in Portugal has been growing, and new exploitation methods are needed. This study intends to determine the properties of particleboards made with very young Paulownia trees from Portuguese plantations. Single layer particleboards were produced with 3-year-old Paulownia trees using different processing parameters and different board composition in order to determine the best properties for use in dry environments. The standard particleboard was produced at 180 °C and a 36.3 kg/cm2 pressure for 6 min using 40 g of raw material with 10% urea-formaldehyde resin. Higher particle size lead to lower-density particleboards, while higher resin contents lead to higher density of the boards. Density has a major effect on board properties with higher densities improving mechanical properties such as bending strength, modulus of elasticity (MOE) and internal bond, lower water absorption but higher thickness swelling and thermal conductivity. Particleboards meeting the requirements for dry environment according to NP EN 312 standard, could be produced with young Paulownia wood with acceptable mechanical and thermal conductivity properties with density around 0.65 g/cm3 and a thermal conductivity of 0.115 W/mK. [ABSTRACT FROM AUTHOR]

The reuse of natural fibers, in order to manufacture a new product, is already becoming popular due to the generation of a series of advantages in social areas. Sugarcane bagasse is a set of tangled fibers of cellulose, produced in large quantities due to increased acreage and industrialization of sugarcane resulting from public and private investments in production aimed for the alcohol industry. The aim of this study was to evaluate the feasibility of producing sheet timber manufacture from the sugarcane bagasse, analyzing mechanical strength properties. A form of metal sheet for the molding of 12 specimens based on sugarcane bagasse and industrialized resin was made. Soon after molding, specimens were submitted to a three-point bending test, with the aid of a press. The analysis of the results allowed to conclude that the tensile strength and the modulus of elasticity did not obtain the minimum values recommended by the standard. The tensile strength must be improved to allow panels to be useful for ordinary strength applications. [ABSTRACT FROM AUTHOR]

branches, acacia, polyvinyl acetate, particleboard, physical properties, mechanical properties The quality of particleboard made from broad-leaved acacia branches and PVAc adhesive was investigated. A non-factorial completely randomized design (CRD) with adhesive contents of 10%, 15%, and 20% was employed. The parameters for testing physical properties included moisture content, density, water absorption, and thickness swelling. The parameters for testing the mechanical properties were modulus of elasticity, modulus of rupture, internal bonding, and screw withdrawal resistance. The results indicates that the concentration of PVAc adhesive has a significant effect on both physical and mechanical properties of the fabricated particleboards. The LSD further test indicates that particleboard with 20% adhesive content has the highest value in strength tests and meets the Indonesian National Standard (Standard Nasional Indonesia/SNI) 032105-2006. It is suitable for non-structural indoor (interior) element. [ABSTRACT FROM AUTHOR]

In the production of particleboard, the chips emerging from the drying oven usually pass into the bonding process without sufficiently cooling down. Moreover, along with the effect of friction during the bonding process, the increased chip temperature boosts the consumption of resin/adhesive and affects the properties of the board. This study investigated the effect of chip temperature during the bonding process on the properties of particleboard. With this aim, the effects were determined for six different temperatures (25 °C, 30 °C, 35 °C, 40 °C, 50 °C, 55 °C) measured during the bonding of the chips. According to the results, optimum board properties were obtained from the groups in which the chip temperature measured during the bonding process was 30 °C - 40 °C. Furthermore, it was determined that chip temperatures of above 40 °C during the bonding process significantly reduced the mechanical properties. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the applicability of sugar beet pulp (SBP) in particleboard production as a substitute for wood material. Two variants of board density, 650 kg/m3 and 550 kg/m3, containing 0%, 25% and 50% of SPB, were evaluated. During the study the following features were measured: modulus of rupture (MOR), modulus of elasticity (MOE), thickness swelling (TS) and water absorption (WA). The results showed that boards containing up to 25% of SBP meet standards for boards for general-purpose used in dry conditions. Further increases in SBP content deteriorated some of the investigated properties of the boards. [ABSTRACT FROM AUTHOR]

This is a bridge between circular economy issues and wood-based panels technology, especially particleboards. Because these composites contain a significant amount of non-wood raw material (10–12% thermoset resin, high hardness laminates, among others), their mechanical recycling leads to an uncontrollable reduction in produced particle size. This problem can be especially significant since the particleboards can be intended for multiple recycling due to the shortening of their service life. This research aimed to produce particles in the cycle of multiple re-milling particleboards and evaluate the selected properties of the produced particles and particleboards. Thus, the response to the following scientific problem can be given: what factors qualitatively and quantitatively influence the properties of the particleboards produced by multi-re-milled particles? The novelty of this research is the approach to recycling the raw materials from particleboards in fully controlled conditions, providing the characterization of produced particles and producing particleboards with close-to-industrial parameters, and, finally, evaluating the features of produced particleboards in the light of raw materials used. The results confirmed that subsequent mechanical recycling of particleboards, where the other panels are made entirely of second-milling particles, leads to an unprofitable and unacceptable reduction in the mechanical properties of the panels. The physical parameters, such as thickness swelling and water absorption, are improved, but this can be the result of increased content of chemical ingredients, which negatively influence the hygienic features of panels (emission of formaldehyde and total volatile organic compounds—TVOC). Further research should be directed towards estimating the optimal addition of mechanically recycled particles to particleboard production. [ABSTRACT FROM AUTHOR]

Urea formaldehyde-based amino resins were prepared in the laboratory using keratin hydrolysate through copolymerization reaction. Conventional urea formaldehyde amino resins were also synthesized without the addition of keratin hydrolysate powder during the reaction. The main aim of this study was developed to keratin hydrolysate-modified urea formaldehyde amino resin adhesive for the bonding of face and core particle. Low formaldehyde content amino resin has been synthesized with the help of different variables factors like urea formaldehyde mole ratio, adding a sequence of keratin hydrolysate and percentage of keratin hydrolysate. The synthesized resins were mixed with ammonium chloride as hardener and the wood-based particle board panels were made. The physical, mechanical and chemical properties of the modified and conventional were determined which include flow time, gel time, solid content and pH. Bond quality between resin and particles was evaluated along with the formaldehyde emission. The optimized results show that percentage of 5% keratin hydrolysate and adding keratin hydrolysate before the third feeding of urea is the best. [ABSTRACT FROM AUTHOR]

A growing world population means that demand for wood-based materials such as particleboard is constantly increasing. In recent years, wood prices have reached record highs, so a good alternative can be the utilization of branches, which can reduce the cost of raw materials for particleboard production. The goal of the study was to confirm the feasibility of using an alternative raw material in the form of Pinus sylvestris L. pine branches for the production of three-layer particleboard. Characterization of the alternative raw material was also carried out, and the bulk density was determined. As part of the research, six variants of particleboard, 0%, 5%, 10%, 25%, and 50%, w/w, and two variants where the first one had the face layer made of branch particles and the core layer made of industrial particles, and the reverse variant (all produced panels were three-layer) were produced and then their physical and mechanical properties were studied. The results show that even if the bulk density of branch particles is significantly higher than industrial material, the internal bond and water absorption rises as branch particle content increases. In the case of bending strength and modulus of elasticity, these were decreased with a branch particle content increase. The conducted tests confirmed the possibility of using the raw material, which was usually used as fuel or mulch, to produce particleboards even in 50% content. The present solution also contributes to the positive phenomenon of carbon storage, due to incorporating the branches' biomass into panels rather than burning it. Further research should be focused on the modification of particle production from branches to obtain lower bulk density and to reach fraction shares closer to industrial particles. Furthermore, the chemical characterization of the pine branch particles (cellulose and lignin content, extractives content, pH value) would provide valuable data about this potential alternative raw material. [ABSTRACT FROM AUTHOR]

Lignin is produced worldwide in pulp mills and is currently mainly used for energy recovery. Because of its chemical properties, one possible utilisation is the production of lignin-based materials. Currently, developed lignin-based adhesives are based mainly on lignosulfonate instead of kraft lignin since lignosulfonate is more reactive than kraft lignin. However, worldwide substantially more kraft lignin is produced. The presented research deals with the development of resin chemically modified with kraft lignin up to 40% (w/w) content of kraft lignin. The synthesis of adhesives is described, and developed adhesives are characterised. Namely, viscosity, mechanical properties of resins and results of differential scanning calorimetry are presented. Furthermore, the developed kraft-lignin-based adhesives were used for the production of particleboards. Pre-pressing in a cold press followed by hot pressing in a laboratory press was used for the production of particleboards. The physical (thickness swelling, moisture uptake, vertical density profile), as well as mechanical (internal bonding, modulus of rupture, modulus of elasticity in three-point bending) properties of particleboards, were evaluated. The results clearly show that kraft lignin can be used for the production of lignin-based adhesives for the production of particleboards. [ABSTRACT FROM AUTHOR]

In recent years, research has been conducted in search of alternative adhesives that are less harmful to human health and the environment. Cardanol derived from cashew nut shell liquid (CNSL) has attracted considerable attention due to its chemical and specific characteristics (antioxidant activity, flame resistance, and hydrophobicity). In this sense, this study aimed to evaluate the quality of particleboards using cardanol instead of urea–formaldehyde (UF) adhesive. Different percentages of cardanol were used (0, 20, 40, 60 and 80%) in which its physicochemical properties were evaluated. The panels were produced with particles of Pinus oocarpa and nominal density of 0.75 g/cm3, their physical and mechanical properties were evaluated, wood-adhesive interface evaluation with scanning electron microscopy (SEM), and the combustibility test. It is concluded that the maximum replacement of UF by cardanol is 5%, since, in this situation, the mentioned properties reach the established norms for the commercialization of the boards. [ABSTRACT FROM AUTHOR]

Nowadays, a significant increase in interest in renewable energy sources can be observed. Wind farms have been one of the solutions representing this trend for many years. One of the important elements of windmills is the blades. The data indicate that what to do with the blades after their use is a global problem, and so it is important to find a way to recycle them. Hence, this work aimed to use these blades in the production of wood-based materials. Two fractions of a fragmented blade were used for the tests: a small one and large one. Boards characterized by densities of 650 kg/m3 and 700 kg/m3 were produced, in which the assumed substitution of the wood material with a polymer was 20% or 40%. Mechanical properties such as bending strength (MOR), modulus of elasticity (MOE), and internal bond strength (IB) were investigated. The 2S65 variant achieved the highest static bending strength and a modulus of elasticity of 2625 N/mm2. The second best result was noted for the 4S65 variant, which was significantly different from the 2S65 variant. In the case of the variants with a density of 700 kg/m3, no significant differences were found and their results were significantly lower. Moreover, research on thickness swelling (TS) after 24 h of immersion and water absorption (WA) were also conducted. The obtained results indicate that the manufactured boards are characterized by good physical and mechanical properties.

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Açaí (Euterpe oleracea Mart.) is an important economic source in the north region of Brazil for agro-industry. However, it generates a huge amount of seed residue as agro-waste. The aim of this study is to evaluate the performance of this residue as reinforcement in particleboards. The medium-density particleboards were manufactured according to the experimental design (22 + 1), considering the parameters with two factors: "Granulometry", for different açaí seed sizes (2.38, 1.19, 0.29, 0.15 and 0.07 mm) and "%Resin", for different resin weight fractions (10%, 12.5% and 15%), both applied in the manufacturing of the composites. Measurements for the Apparent Density Thickness Swelling and Water Absorption (WA) of the particleboards were performed. Mechanical properties of particleboards were analyzed through top and surface Screw Withdrawal and Internal Bonding test. In addition, the morphology of surface from particleboards was evaluated through Scanning Electron Microscopy The results of TS for 24 h, WA for 2 and 24 h, and IB showed that the particle size was a significant factor (p <.05). These results established that the highest particle sizes provided lower percentages of absorption. The results of Screw Withdrawal did not achieve the requirements established by NBR 14810–2:2018 standard. Besides that, the results presented statistical difference, considering the particle size and the interaction between parameters ("%Resin" and "Granulometry"), which resulted in a p -value <.05. For the Internal Bonding test, the composite with highest particle size exhibited the best performance compared to the other ones. [ABSTRACT FROM AUTHOR]

The demand for particleboard has been increasing over the years. Currently, most particleboards are produced from wood which may not be sustainable in the long term. Therefore, there is need of exploring alternative materials such as making particleboards from waste materials. This study investigated the mechanical properties of particleboard consisting of waste leather shavings and waste papers blended together by unsaturated polyester. A single-layered particleboards were manufactured using compression method. Different resin contents (60%, 70%, 80%, and 90%) and leather/paper ratios (100:0, 25:75, 50:50, 75:25) were used to determine the effects on the mechanical properties (internal bond, bending strength, compression, and impact strength) of fabricated boards. From the results of this study, it was found that leather shavings and waste papers can be used as alternative raw materials for particleboard production and that mechanical properties were depended on the resin content and the blend ratio. Also, mechanical properties were reduced with resin content increment, except for impact strength, and improved by high paper blend ratio. It could be concluded that the produced particle panels could be used for indoor application or interior equipping. Additionally, it is recommended that further studies can be done on morphological analysis to establish the bonding between the particles and matrix. [ABSTRACT FROM AUTHOR]

Nanoscience and nanotechnology offer a plethora of possibilities for improving the qualities of wood composites. The present study aimed to use nanotechnology to develop low formaldehyde emitting particle board as ecologically acceptable composites. Conventional urea Formaldehyde resins were prepared by the percentage of second urea at 10%. Nano-wollastonite, silica and montomorillonite with the size range of 25-100 nm were applied at 0.5-2.0% based on the weight of resin. The nano-reinforced resins were admixed with suitable hardener and the panels were made. Formaldehyde emission reduction in wood panel products is critical and it can be partially controlled by using resin modification. The effectiveness of nanoparticle addition to reducing formaldehyde emission from wood particle board was examined by the perforator method as per IS 13745 (1993). Physical and Mechanical properties were evaluated according to IS 3087 (2005). The result indicated distinctly lower water absorption and thickness swelling of panels produced with 1.5 %, 1.5 % and 2.0 % nano silica, nano montomorillinite and nano wollastonite respectively. The results showed that static bending of the produced composite varied from 21.07 to 28.86 N/mm2 of MOR and from 2246 - 3353 N/mm2 of MOE; while internal bond strength (IB) varied from 0.35 to 0.58 N/mm2. As per IS 3087 (2005) requirements, 1.5 % nano silica and montomorillonite and 2.0 % nano wollastonite mechanically modified urea formaldehyde based agro composites gave the best results for grade II particle boards. The study concluded that nanoparticle addition reduces the formaldehyde content in the panel without affecting the strength properties. [ABSTRACT FROM AUTHOR]

The present paper shows the research conducted for the assessment of magnesium lignosulfonate as a potential binder for the particleboard manufacturing. Magnesium lignosulfonate (15 wt.%) in a pure state (as powder) was used first as binder for particleboard manufacturing, and was considered as reference for the next investigations, where the lignosulfonate was gradually modified by oxidation with hydrogen peroxide, than by addition of crosslinking agents, such as diphenylmethane diisocyanate (PMDI) in shares between 1% and 3% of the dry particles weight and glucose (15% of the lignosulfonate content). Mixed beech wood (30%) and spruce wood (70%) particles were used in the single mat configuration of the particleboard. Mechanical properties, formaldehyde emission, water absorption and thickness swelling were investigated for the manufactured panels in the laboratory conditions. The results showed that the oxidation process of lignosulfonate and addition of PMDI and glucose have positive impact on lowering formaldehyde emission and improving mechanical properties requested by EN 312 (2004) standard. Water absorption and thickness swelling tests performed on the samples cut from the experimental panels have shown their low resistance to water, recommending them to indoor use. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Warsaw University of Life Sciences - SGGW, Forestry & Wood Technology is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to analyse the contractual compression strength and modulus of elasticity under compression of ten commercially available wood composites of various thickness, density, structure and surface finish. Density and density profiles have also been performed. The tests showed that there is no significant dependence of the compression strength and MOEC on the density of composites. Celem badań była analiza umownej wytrzymałości na ściskanie i modułu sprężystości przy ściskaniu dziesięciu dostępnych na rynku kompozytów drewnopochodnych o różnej grubości, gęstości, strukturze i wykończeniu powierzchni. Zbadano również gęstość i profile gęstości badanych tworzyw. Badania wykazały, że brak jest istotnej zależności wytrzymałości na ściskanie oraz MOEC od gęstości tworzyw. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the potential of magnesium lignosulfonate as adhesive in particleboard manufacturing. Diphenylmethane diisocyanate (PMDI) between 1% and 3% and glucose (1% of the lignosulfonate content) were added as potential cross-linkers in the adhesive formulations. Mixed beech and spruce wood, 30% beech wood and 70% spruce wood, were employed for the configuration of the panel structure. The density, mechanical properties and formaldehyde emission of single-layer particleboard were investigated. Spectroscopic analysis (FTIR) revealed structural changes brought by oxidation that may indicate depolymerization by the splitting of C-O-C bonds and formation of carbonyl groups. Mechanical properties were improved, and the highest average values were recorded for panels having as adhesives oxidized lignin with cross-linkers as follow: 15 N/mm2 (MOR), 3320 N/mm2 (MOE) and 0.48 N/mm2 (IB). The density profile presented higher values for faces in case of oxidized lignin panels. Changes were observed for oxidized lignin with cross-linker panels wherein the core had higher values. The results showed that the panels manufactured with adhesives composed of oxidized lignosulfonate (20% of the dried wood particles weight) and the addition of PMDI and glucose in various percentages have a positive influence on their formaldehyde release and mechanical properties requested by EN 312 (2004) standard. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Warsaw University of Life Sciences - SGGW, Forestry & Wood Technology is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wood is a highly optimised lightweight material showing excellent mechanical properties in the fibre direction. However, strength and stiffness are low perpendicular to grain. Due to knots, stem taper and spiral grain, the wood material includes local and global fibre deviations. Mechanical disintegration of logs into veneers and sawn timber is more or less ignoring the orientation of the natural wood structure, reducing mechanical properties of the grown tree. This is also true for particle production processes e.g. for OSB or particleboard, which also applies cutting and crushing technologies. As a result, conventional mechanical disintegration of logs means, the destruction of a highly optimised structure, which is always accompanied by a significant reduction of mechanical properties. The basic idea of the novel non-cutting chipless particle production process is to preserve the natural structure by employing squeezing and shear forces. These squeezing and shear forces lead to the mechanical disintegration of the logs primarily in the fibre direction, whereby long fibrous particles, so-called macro-fibres, are gained. Macro-fibres gained from this process prove excellent strength properties. [ABSTRACT FROM AUTHOR]

This study investigated the effects of the pressing temperature on the mechanical and physical properties of binderless bark particleboard made from Gelam bark waste and the improvement of those properties. In addition, the thermal insulation properties of the particleboard were determined. Four different temperatures (140 °C, 160 °C, 180 °C, and 200 °C) were used to make single-layer binderless bark particleboard with a target density of less than or equal to 0.59 g/cm3. Results revealed that the pressing temperature affected the mechanical properties (modulus of rupture, modulus of elasticity, and tensile strength perpendicular to panel surface), which increased as the temperature increased, and the physical properties (thickness swelling and water absorption), which decreased as the temperature increased. Based on the Tukey test, increasing the temperature from 180 to 200 °C did not significantly affect the mechanical or physical properties, except for the tensile strength perpendicular to panel surface. None of the mechanical properties met SNI standard 03-2105-2006 (2006); however, the 12% maximum thickness swelling requirement was met for binderless bark particleboard hot-pressed at 200 °C. Binderless bark particleboard hot-pressed at 200 °C had high water resistance, regardless of its low strength, and a thermal conductivity value of 0.14 W/m·K. [ABSTRACT FROM AUTHOR]

The search for materials made from renewable resources and free of toxic substances is a global trend towards cleaner production, which can be extended to the development of wood-based panels. However, the industrial sector of wood-based panels has been facing several gaps and challenges related to the shortage of wood raw materials for panel manufacturing with the toxic emissions of traditional adhesives. Camellia oleifera shell (COS), as a common waste, is a potential alternative raw material for wood-based panels and also has an important role in alleviating environmental stress. Faced with these problems, the aim of this study was to assess the technical feasibility and environmental aspects of manufacturing particleboard from COS waste at scale. For this purpose, particles made from conventional eucalyptus species were used as particleboard reinforcing phase. Particleboard was manufactured and tested by varying some production parameters, namely: of 10, 20 and 30% content of COS addition; and adhesive types of melamine-urea-formaldehyde (MUF) and polymeric 4–4 diphenylmethane diisocyanate (pMDI) adhesives. The results showed that the physical-mechanical properties of COS-based particleboards were satisfactory for a 10% MUF resin loading or a 3.5% pMDI resin loading. COS-based particleboards with 20–30% COS content similarly met the standards and requirements for non-structural applications. This study presents an informative discussion for decision makers in the wood-based panel industry, providing a trade-off between lower adhesive application and higher COS substitution that is more suitable for direct production at total plant scale. • The feasibility of camellia oleifera shells for particleboard production is explored. • Qualified particleboard with low cost using camellia oleifera shells is manufactured. • The MUF bonded particleboard with 30% shells meet excellent dimensional stability. • The pMDI bonded particleboard with 30% shells showed ideal mechanical properties. [ABSTRACT FROM AUTHOR]

Considering the significant demands for construction products and the increasing disposals of plastic and agroforestry residues, this research evaluated the influence of recycled particles of polyethylene terephthalate (PET) inserted in the manufacture of five particleboard prototypes based on Pinus elliottii wood and castor-oil-based polyurethane resin (CPUR). The following panel traits were obtained: 100% pine wood, 0% PET and 10% CPUR (M100P-0PET-10C); 70% pine, 30% PET, and 10% CPUR (M70P-30PET-10C); 50% pine, 50% PET, and 10% CPUR (M50P-50PET-10C); 70% pine, 30% PET, and 5% CPUR (M70P-30PET-5C); and, 50% pine, 50% PET, and 5% CPUR (M50P-50PET-5C). Panels were evaluated according to physical (density, moisture content, thickness swelling, and water absorption), mechanical (modulus of rupture, modulus of elasticity, perpendicular tensile), and morphological tests (scanning electron microscope). M50P-50PET-10C particleboards revealed the best performance in the physical and mechanical tests, as well as M70P-30PET-10C and M50P-50PET-5C panels showed equivalent results. The findings suggested a notable environmental contribution and a great economic feasibility. Thus, it is possible to obtain wood-based particleboards manufactured from recycled PET, reusing this highly discarded non-biodegradable plastic and using a smaller volume of adhesive, with physical-mechanical properties that meet the expected performance for this bioresource-based product. [ABSTRACT FROM AUTHOR]

The study assessed the effect which plantain pseudostem particles in combination with cocoa pod had on the physical and mechanical properties of particleboards. This is against the backdrop that previous studies have indicated that particleboards produced from only plantain pseudostem particles had very good physical and mechanical properties whilst those produced from only cocoa pod had poor physical and mechanical properties. The two biomass materials were blended at the following ratios: 100:0; 90:10; 70:30; 50:50; 30:70; 10:90 and 0:100 (plantain pseudostem: cocoa pod). Cassava starch and urea formaldehyde were used as adhesives. Physical and mechanical properties of particleboards tested using ASTM standard procedures were: density, thickness swelling, water absorption, modulus of elasticity, modulus of rupture, hardness and internal bond strength. The results indicate that with the exception of density, all the physical and mechanical properties of the particleboards improved significantly with increased percentages of plantain pseudostem in the biomass mix. This is due to low bulk density, relatively high lignin content and higher aspect ratio of the plantain pseudostem particles. Generally, the particleboards produced met or exceeded the EN and JIS standard requirements. At 5% level of significance, the raw material mix and the adhesive type had significant effect on the physical and mechanical properties of the particleboards produced. In view of the results obtained the manufactured particleboards could be utilized for general purpose work including furniture for interior environments. [ABSTRACT FROM AUTHOR]

In this study, the optimum conditions for manufacturing particleboard-based waste cotton stalks were evaluated to achieve a good performance of mechanical properties. The response surface methodology (RSM) is used to calibrate the experiment results based on input variables consisting of the weight ratio of melamine formaldehyde to urea-formaldehyde (MU) resins, shelling ratio (SR), and the proportion of cotton particles to poplar particle (CP) in the core layer. An adaptive harmony search (AHS) algorithm is offered to search the optimum constructing conditions of mechanical properties for the composite particleboard using two optimization models. The optimum conditions are evaluated using maximum performance of mechanical properties. Besides, the optimum conditions are searched based on the material cost of the mechanical properties of composite particleboard that are utilized in its constraints. The results showed that the RSM can provide a perfect prediction for the mechanical properties of particleboard. The AHS is successfully applied to optimize the composite conditions. In the first optimization application, the optimal point is obtained for input variables in composite as 21.91% MU, 37.10% SR, and 13.54% CP. However, in the second condition, the optimum conditions are obtained for a good level as 18.32% MU, 51.71% SR, and 8.37% CP in the core layer. [ABSTRACT FROM AUTHOR]

• Cocoa almond husk waste was destined as alternative to produce MDP panels. • Extractives and ash may cause a damage in the adhesive-particles interaction. • Decrease in resin-to-particle ratio may cause damage to the mechanical properties. • Low percentages of cocoa waste did not hamper the properties of the panels. • Inclusion up to 21% of cocoa waste meet the standardization for all properties of MDP. This research proposed to investigate a possible destination for the cocoa waste as component in the core layer of Medium Density Particleboards (MDPs) and to evaluate the effect of the waste insertion on the physical-mechanical properties of the panel. The core layers of the MDPs were composed by different percentages of cocoa wastes (0, 25, 50, 75 and 100%) in combination with pine wood. The targeted density of the panels was pre-established in 0.7 g cm−3, bonded with urea-formaldehyde. The cocoa waste showed higher extractives content (34.8%) when compared with the pine wood (4.0%). The inclusion of the waste did not cause a significant difference in the moisture and bulk density of the panels; however, there was an increase in water absorption 24 h (71–105%) and thickness swelling 24 h (13–35%). Despite the values of the mechanical properties decreased in general, in low percentages, the cocoa waste does not prevent the use of the MDPs as furniture for internal environments. The results show that the cocoa waste has potential for being applied as raw material in the core layer of the MDP, in percentages up to 21%. The lignocellulosic wastes are promising alternatives for the achievement of the required current context of the sustainability and should be highlighted with research focused on their management for the development of added value materials. [ABSTRACT FROM AUTHOR]

There is a global concern about the types of adhesives used for the binding of wood particles, most of which include formaldehyde in their formulation. The aim of this work is to study the effect of raw montmorillonite (Mt) particles on blended urea formaldehyde (UF)/soy protein (SP) adhesives for the manufacture of wood particleboards to reduce the use of this carcinogenic component. Rheology showed that Mt does not alter the viscosity of adhesives at high shear rates, so they can be applied by spray. Thermogravimetric analysis/derivative thermogravimetry (TGA/DTG) analysis revealed an enhancement of their thermal stability due to the presence of clay particles. Polymer–Mt interaction was studied by small amplitude X‐ray scattering and scanning electron microscopy. According to these results, the exfoliated structure of the clay particles was achieved. Wood particleboards were manufactured with UF/SP/Mt adhesives in order to study their mechanical properties. The three‐point bending test showed that Mt particles improved the modulus of both rupture and elasticity. UF/SP/Mt resins proved to be a prominent product for the development of environmentally friendlier particleboards with desirable mechanical properties. [ABSTRACT FROM AUTHOR]

Addition of mineral filler in the surface layer of three-layer particle board and its influence on material properties was studied as a function of filler content. Three-layer particle board with a density of 700 kg m−3 and 0, 10, 20, and 40% weight fraction (wt-%) of calcium carbonate filler in surface layers was produced in laboratory scale using urea formaldehyde as resin. The effect of inorganic filler on elastic and strength properties, dimensional stability and formaldehyde emissions was investigated. The results demonstrated that the addition of filler in amounts up to 10 wt-% in surface layers does not significantly affect mechanical properties. Further increase in filler addition above 10 wt-% resulted in a nearly linear decrease in bending properties and increase in water uptake, however did not significantly affect dimensional stability and formaldehyde emissions. [ABSTRACT FROM AUTHOR]

Particleboards were manufactured using coconut fibers (Cocos nucifera). The panels were made using different green adhesives, i.e., native potato starch, citric acid, and glutardialdehyde modified potato starch, that were applied at 10%, 12%, and 15% based on oven-dry particle weight for each green adhesive type. The properties of the panels were determined according to the Japanese industrial standard. The results showed that the panels that were bonded with the 15% citric acid-modified starch green adhesive yielded the best mechanical properties (the modulus of elasticity, modulus of rupture, and internal bonding strength). The modified potato starch had potential as a green adhesive used for the production of particleboards from coconut fibers. [ABSTRACT FROM AUTHOR]

At present, a large number of waste textiles are disposed through incineration and burial, which cause serious environmental pollution. Therefore, recycling textile wastes into high mechanical products with eco-friendly method is an urgent issue. Based on the above status quo, three kinds of 3D waste denim fiber needled felts/epoxy composites (3DWECs) with different areal densities of the mono-layer fiber web were designed and fabricated, and the effect of the areal density of the mono-layer fiber web on its mechanical properties was studied in this work. The cross-section morphologies of 3DWECs were also examined. Tensile, bending and compressive test results revealed that 2# 3DWECs (the planar density of mono-layer fiber webs was 557 g/m2) possessed better mechanical properties than 1# 3DWECs and 3# 3DWECs. Both the static and dynamic mechanical testing results showed that 3D waste denim fiber needled felts acting as the reinforcement played an essential role in the bearing function. Moreover, the peel tests indicated that the peel strengths of the 3DWECs were above the limits of the Chinese National Standard for particle board. The composites have the potential as a substitute for some particle boards. [ABSTRACT FROM AUTHOR]

It is known that there is a correlation between hydration heat and physico-mechanical properties of wood based cement panels. Cement hydration is affected by many variables, such as chemical composition, water/cement ratio, wood/cement ratio, wood chemical properties, mineral additions and producing conditions. This study mainly aimed to investigate the effects of press temperature on some properties of three-layer cement bonded particleboard made from the particles of spruce (Picea orientalis) and poplar (Populus tremula). For this purpose, a total of 16 experimental board groups with 1200 kg/m³ target density and 1/3 wood-cement ratio were produced at the press temperatures of (20, 30, 40, 50, 60, 70 and 80) °C. As cement curing accelerator, CaCl2 was used at a rate of 5 % (cement weight basis). The physical, mechanical and thermal properties of the boards were determined. The results indicated that the press temperature substantially affected the properties of cement-bonded particleboard depending on the wood species. In the light of this study, the optimum temperatures in producing of cement-bonded particleboard were found as 40 °C for poplar wood and 60 °C for spruce wood. [ABSTRACT FROM AUTHOR]

Low density of hemp hurd (Cannabis Sativa L), better end of life impact, performance comparable to wood chips and low energy requirement for cultivation make it a suitable alternative raw material for particleboards (Pb). However, due to concerns about sustainability and formaldehyde emissions, it is essential to develop the new bio-based resins from renewable resources. In this research, the mechanical and physical properties of Pb produced from hemp hurds (HH) and a variety of resins: Urea-formaldehyde (UF), formaldehyde-free acrylic resin (Acrodur®) and bio-based soy resin (Soyad™) were compared to those of wood particles (WP) bonded with UF. The results indicate that boards from HH are generally lighter than WP with a 5.6% variation between HH+UF and WP+UF. Hemp boards based on soy-resin showed higher tensile performance, with an average of 0.43 MPa compared to the 0.28 MPa and 0.24 MPa of (HH+UF) and (WP+UF) respectively. Nevertheless, thickness swelling (TS) of HH+UF (27%) was the least, while there was no significant difference in the water absorption (WA) compared to HH+Soyad4740, both were still lower than that of WP+UF. The overall outcome shows that bio-based soy resin can be a suitable alternative to UF as a binder in Pb production. [ABSTRACT FROM AUTHOR]

Olive prunings are, in the majority of cases, treated as agricultural residues and burned in open fires or mulched into soil. However, they can be exploited in various ways and offer added value. Apart from their exploitation for energy purposes, they can be potentially used for the production of other bio-commodities such as particleboards, used in the construction and furniture sector. In this light, the current study investigates the potential of producing particleboards from olive tree prunings by replacing common wood. Harvested olive tree prunings, thin branches along with leaves, were used for the production of particleboards by gradually replacing commercial wood at 20%, 40%, 60%, 80% and 100% rate. Based on the results achieved, a maximum substitution level of 40% of the conventional wood with pruning material can be applied. The mechanical properties of the panels were reduced by increasing the substitution level. This may be attributed to the higher amount of bark compared to the conventional wood chips, and the presence of leaves. On the other hand, particleboard properties such as the formaldehyde emissions of the boards (along with the thickness swelling) are reduced by increasing the substitution level, which makes the panels safer in terms of indoor pollution and human health and more consumer friendly, and attractive for the market. • Particleboards from two varieties of Olive tree prunings (OTP) mixed with commercial wood were fabricated. • Higher substitution reduced the panels' mechanical properties and lowered the formaldehyde content and thickness swelling. • 20% OTP/80% commercial wood in order to have comparable properties to the reference panels. • Findings support increased valorization of olive tree pruning waste into particleboard. [ABSTRACT FROM AUTHOR]

In this paper, the impacts of heartwood and sapwood usage on the physical, mechanical, and surface properties and formaldehyde emission of particleboard are investigated. European Larch (Larix decidua) trees are chosen as a raw material. The logs are divided into three segments: sapwood, heartwood and total wood. The highest amounts of cellulose (51,54%), and hemicelluloses (22,24%) in the sapwood, followed by total wood, and the heartwood, respectively. However, the highest amount of lignin (30,54%) was found in the heartwood. The highest extractives values are obtained from heartwood, followed by total wood, and the sapwood, respectively. While the lowest pH value (3,03) is found in heartwood, the sapwood samples provide the highest values (4,95). The highest ash (0,49%) content and amount of condensed tannin (13,89%) are extracted from heartwood, followed by total wood, and sapwood, respectively. The test panels manufactured from sapwood have the smoothest surface (7,49 μm (Ra), 48,86 μm (Ry), and 35,12 μm (Rz)) and the lowest contact angles (67,8°), while the roughest surface (14,20 μm (Ra), 68,05 μm (Ry), and 50,02 μm (Rz)) and highest contact angle (96,9°) are obtained from the panels of heartwood. The thickness swelling (19,88%) and formaldehyde emission (7,28%) values of the panels manufactured from heartwood are significantly lower than the panels manufactured from the total wood and sapwood. The highest modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB) values are observed on sapwood, respectively, 15,60 MPa (MOR), 2201 MPa (MOE), and 0,523 MPa (IB). These mechanical strength values (MOR, MOE, and IB) are followed by total wood, and the heartwood, respectively. Surface smoothness and wettability of the particleboards manufactured from sapwood are better than those of total wood and heartwood. [ABSTRACT FROM AUTHOR]