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Chicken eggshells are a useful waste that may be used somewhere rather than being placed in landfills. They are created in poultry hatcheries, the food sector (making pasta, cakes, and egg products), or our homes. In this project, this study aimed to investigate the possibility of producing plywood using a filler in the gluing process in the form of ground eggshells. This study includes the production of plywood with 0, 1, 5, 10, and 20 parts by weight (pbw) of eggshell filler (called E0, E1, E5, E10, and E20, respectively) and one reference variant with rye flour (10 pbw; hereafter called REF10). This research also includes investigating the produced panels' selected physical and mechanical properties. The results show that chicken eggshells can be used to produce plywood if the right amount of filler is chosen to improve specific mechanical and physical properties. Promising properties were obtained in the determination of the modulus of elasticity under bending (MOE) for samples E5 (11,310 N mm−2) and E10 (11,394 N mm−2) and modulus of rupture (MOR) for sample E5 (130 N mm−2). The results for the internal bond (IB) show that the addition of 5 pbw of filler in the form of ground shells shows good properties with as much as 5.23 N mm−2, but still, the reference sample with the addition of filler in the form of rye flour has higher results of 6.22 N mm−2. In the test of water absorption of fillers, the absorption of calcium carbonate is 207% and is lower than that of rye flour (224%). For the swelling thickness results, the E10 sample showed the weakest results of 7.6% after 2 h and 8.9% swelling after 24 h. [ABSTRACT FROM AUTHOR]

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

This study aimed to evaluate the bondability of beech and alder wood modified through styrene polymerization within the wood lumen. Unmodified wood samples served as the reference material. Bondability was tested using four adhesive types commonly used in wood technology: polyvinyl acetate (PVAc), urea-formaldehyde (UF), phenol-resorcinol-formaldehyde (PRF), and epoxy resin. In addition to shear strength measurements, the adhesive density profile was also assessed. Results indicated that styrene modification generally reduced wood bondability, with reductions in shear strength ranging from 8% to 23% for beech wood and 1.6% to 29% for alder wood, depending on the adhesive type. The only exception was observed with the epoxy adhesive, which showed a 13% improvement in bonding quality for modified wood. These findings suggest that while styrene modification may enhance specific properties of wood, it can adversely affect its adhesion performance with some adhesive systems, except epoxy, which displayed improved compatibility with styrene-modified wood. The study offers insights for selecting suitable adhesives when using modified wood in structural applications. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Recycling upholstery textiles is challenging due to the complexity of materials, which often include a mix of fabrics, foams, and adhesives that are difficult to separate. The intricate designs and layers in upholstered furniture make it labor-intensive and costly to dismantle for recycling. Additionally, contaminants like stains, finishes, and flame retardants complicate recycling. Despite these difficulties, recycling upholstery textiles is crucial to reducing landfill waste and conserving resources by reusing valuable materials. It also helps mitigate environmental pollution and carbon emissions associated with producing new textiles from virgin resources. The presented research aimed to establish the feasibility of incorporating textile fibers from waste artificial leather fibers from the upholstery furniture industry into the structure of high-density fiberboards. The bulk density of samples with wood fiber was 28.30 kg m−3, while it was 25.77 kg m−3 for textile fiber samples. The lowest modulus of elasticity (MOE) was 2430 N mm−2, and it was 3123 N mm−2 for the reference sample. The highest bending strength (MOR) was 42 N mm−2, and the lowest was 27.2 N mm−2. Screw withdrawal resistance decreased from 162 N mm−1 in the reference sample to 92 N mm−1 with 25% artificial leather fibers. The internal bond (IB) strength ranged from 1.70 N mm−2 (reference) to 0.70 N mm−2 (25% of artificial leather fibers content). Water absorption ranged from 81.8% (1% of artificial leather fibers) to 66% (25% of artificial leather fibers content). It has been concluded that it is possible to meet the European standard requirements with 10% addition of the artificial leather fiber content. This approach positively contributes to carbon capture and storage (CCS) policy and mitigates the problem of such waste being sent to landfills. The research shows that while selected mechanical and physical parameters of the panels decrease with a rising content of recycled textile fibers, it is possible to meet proper European standard requirements by adjusting technological parameters such as nominal density. [ABSTRACT FROM AUTHOR]

This manuscript explores the development of sustainable biopolymer composites using suberin extraction waste, specifically suberinic acid residues (SAR), as a 10% (w/w) reinforcing additive in polylactide (PLA) and thermoplastic starch–polylactide blends (M30). The materials were subjected to a detailed analysis using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA) to assess their thermal, mechanical, and structural properties. The study confirmed the amorphous nature of the biopolymers and highlighted how SAR significantly influences their degradation behavior and thermal stability. M30 exhibited a multi-step degradation process with an initial decomposition temperature (T5%) of 207.2 °C, while PLA showed a higher thermal resistance with decomposition starting at 263.1 °C. Mechanical performance was assessed through storage modulus (E′) measurements, showing reductions with increasing temperature for both materials. The research provides insights into the potential application of SAR-enriched biopolymers in sustainable material development, aligning with circular economy principles. These findings not only suggest that SAR incorporation could enhance the mechanical and thermal properties of biopolymers, but also confirm the effectiveness of the research in reassurance of the audience. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Nonwoven upholstery fabric is a waste product which is mainly generated during upholstered furniture production. The polyester composition makes it problematic to recycle and reuse this product. This study examined the manufacturing process of nonwoven fabric-reinforced plywood composites and their selected mechanical and physical properties. Nonwoven fabric was integrated between veneers bound with urea–formaldehyde resin to improve standard layered composites' mechanical and physical properties. Several board variants were produced, differing in the position of the nonwoven layers in the composite structure. The composites were evaluated for modulus of rupture (MOR), modulus of elasticity (MOE), internal bond, and screw withdrawal resistance, among others. The results showed that the addition of nonwoven fabric significantly improved some properties, like internal bond and screw withdrawal resistance. Variants with strategically placed nonwoven layers showed the highest performance increases. The results underscore the potential of nonwoven fabric as an effective reinforcing material, offering a path to developing high-performance plywood composites suitable for demanding applications. Another environmental advantage is that the nonwoven fabric waste used in the tested plywood production has not been subjected to burning or landfilling but, through its incorporation into plywood structure, has positively contributed to the Carbon Capture and Storage (CCS) policy. The findings advocate for a circular economy approach, in which industrial waste is effectively repurposed, contributing to the development of green materials in the wood-based composite industry. [ABSTRACT FROM AUTHOR]

This study investigates the potential of utilizing hazelnut shells (HS) as an innovative filler in three-layer plywood technology, addressing the growing need for sustainable, high-performance materials. Traditional plywood production relies on adhesives enhanced with various fillers to improve physical, mechanical, and operational characteristics. This research explores using native, chemically modified, and activated carbon derived from hazelnut shells as fillers in urea–formaldehyde (UF) resin. The produced plywood's mechanical properties, water absorption, and formaldehyde emissions were thoroughly analyzed. Key findings demonstrate that incorporating 10 part by weight (pbw) native hazelnut shell flour significantly enhances the modulus of rupture (MOR) to 138.6 N mm−2 and modulus of elasticity (MOE) to 13,311 N mm−2. Chemically modified hazelnut shell flour achieves optimal results at 5 pbw, while activated carbon from hazelnut shells, even at 1 pbw, markedly improves bonding strength (2.79 N mm−2 referred to 0.81 N mm−2 for reference sample without filler added). Notably, activated carbon effectively reduces formaldehyde emissions (2.72 mg 100 g−1 oven dry panel referred to 3.32 mg 100 g−1 oven dry panel for reference samples with 10 pbw filler) and improves water resistance, indicating better further dimensional stability and lower environmental impact. The study also shows that excessive filler content negatively affects strength parameters, confirming the importance of optimizing filler concentration. These results highlight the potential of hazelnut shells as an eco-friendly alternative filler in plywood production, contributing to waste valorization and environmental sustainability. This study supports the practical application of hazelnut shell fillers, promoting a circular economy and reducing reliance on traditional, less sustainable materials, thus providing a valuable solution for the wood composite industry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth's climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. Phase change materials (PCMs) can store and release heat when it is abundant during the day (e.g., from solar radiation), for use at night, or on chilly days when buildings need to be heated. As a consequence, buildings use less energy to heat and cool, which lowers greenhouse gas emissions. Consequently, research on thermally active medium-density fiberboard (MDF) with PCMs is presented in this work. MDF is useful for interior design and furniture manufacturing. The boards were created using pine (Pinus sylvestris L.) and spruce (Picea abies L.) fibers, urea–formaldehyde resin, and PCM powder, with a phase transition temperature of 22 °C, a density of 785 kg m−3, a latent heat capacity of 160 kJ kg−1, a volumetric heat capacity of 126 MJ m−3, a specific heat capacity of 2.2 kJ kgK−1, a thermal conductivity of 0.18 W mK−1, and a maximum operating temperature of 200 °C. Before resination, the wood fibers were divided into two outer layers (16%) and an interior layer (68% by weight). Throughout the resination process, the PCM particles were solely integrated into the inner layer fibers. The mats were created by hand. A hydraulic press (AKE, Mariannelund, Sweden) was used to press the boards, and its operating parameters were 180 °C, 20 s/mm of nominal thickness, and 2.5 MPa for the maximum unit pressing pressure. Five variants of MDF with a PCM additive were developed: 0%, 5%, 10%, 30%, and 50%. According to the study, scores at the MOR, MOE, IB, and screw withdrawal resistance (SWR) tests decreased when PCM content was added, for example, MOE from 3176 to 1057 N mm−2, MOR from 41.2 to 11.5 N mm−2, and IB from 0.78 to 0.27 N mm−2. However, the results of the thickness swelling and water absorption tests indicate that the PCM particles do not exhibit a substantial capacity to absorb water, retaining the dimensional stability of the MDF boards. The thickness swelling positively decreased with the PCM content increase from 15.1 to 7.38% after 24 h of soaking. The panel's thermal characteristics improved with the increasing PCM concentration, according to the data. The density profiles of all the variations under consideration had a somewhat U-shaped appearance; however, the version with a 50% PCM content had a flatter form and no obvious layer compaction on the panel surface. Therefore, certain mechanical and physical characteristics of the manufactured panels can be enhanced by a well-chosen PCM addition. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Non-food use of solid residues from the dairy industry as a binder in dry-formed fiberboard technology. The research investigated the possibility of using solid residues from the dairy industry as a binder in dry-formed fiberboard technology. The scope of work included the production of boards with a mass content of milk powder of 0%, 10%, 12%, 15%, and 20% (concerning the totally dry mass of wood fibers) and studying their selected physical and mechanical properties. The results show that the properties of the produced boards are related to the mass amount of the binder, and that is, using the right amount of binder makes it possible to obtain values that meet the requirements of the relevant European standards. [ABSTRACT FROM AUTHOR]

Finishing coatings used in the wood-based composite industry play a key role in the final appearance of the finished product. However, the use of such coatings is not only for aesthetic purposes, but also to protect the product against surface damage and moisture or to minimize the emission of harmful substances. The latter is an extremely important factor in terms of safety for both the manufacturer and the user, which is why the emissivity test is one of the most important tests conducted in this case. Carbon-rich materials, such as those remaining from the extraction of birch bark, can fulfill the role of minimizing the emission of harmful substances. In this article, an attempt to create coatings in the form of a film by combining a biopolymer with suberinic acid residues (SARs) was made. Two types of biopolymers were used, polylactide (PLA) and polycaprolactone (PCL), in various polymer–SAR ratios. Suberinic acid as a residue is a raw material that can potentially contribute positively to the fixing of CO2 from the atmosphere, which creates the possibility for further use. As part of this study, the obtained coatings were tested in terms of scratch resistance, relative hardness, cold liquids, total volatile organic compounds (TVOCs), formaldehyde emission, surface absorption, etc. Differences between the polymers used and the effect of the SAR additive on selected surface properties were demonstrated. The addition of carbon-rich SAR significantly improves gas barrier properties of the PLA- and PCL-based surface finishing materials. The relative hardness and scratch resistance also increased with rising SAR content. However, the increasing content of SAR filler acts as a limiter in the depth of penetration of the deposited surface finishing materials onto the wood surface. It is possible to state that this innovative approach regarding (1) the utilization of biopolymers as a matrix, instead of conventional, crude oil-based resins, and (2) the incorporation of post-processed carbon-rich waste lignocellulosic materials to produce the surface finishing and/or protective films has been confirmed. [ABSTRACT FROM AUTHOR]