Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (108)

Search Parameters:
Keywords = veneer mechanical properties

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
19 pages, 2592 KiB  
Article
Lignin-Based Carbon-Fiber-Reinforced LVL Beams for Landscape Timber Structures
by Xuebo Li, Yuan Niu, Zhanpeng Jiang, Jiuyin Pang and Xiaoyi Niu
Polymers 2025, 17(15), 2030; https://doi.org/10.3390/polym17152030 - 25 Jul 2025
Viewed by 296
Abstract
This study focuses on the development of lignin-based carbon-fiber-reinforced laminated veneer lumber (LVL) beams for garden timber structures, addressing wood shortages and environmental concerns. The research consisted of three main phases: the extraction and characterization of the lignin from corn stalks; the preparation [...] Read more.
This study focuses on the development of lignin-based carbon-fiber-reinforced laminated veneer lumber (LVL) beams for garden timber structures, addressing wood shortages and environmental concerns. The research consisted of three main phases: the extraction and characterization of the lignin from corn stalks; the preparation and characterization of lignin-based carbon fibers; the fabrication and testing of reinforced LVL beams. Lignin was extracted from corn stalks using a deep eutectic solvent, followed by the preparation of lignin-based carbon fibers through electrospinning. These carbon fibers were integrated with poplar veneers to create reinforced LVL beams. The test results demonstrated significant improvements in mechanical properties, with the reinforced LVL beams exhibiting a 17% increase in elastic modulus and a 30% enhancement in flexural strength compared with conventional LVL beams. Notable improvements were also observed in tensile strength, compressive strength, and shear strength. This research provides a novel approach for producing high-value-added carbon fibers from agricultural waste, advancing the development of sustainable building materials. Full article
(This article belongs to the Section Biobased and Biodegradable Polymers)
Show Figures

Figure 1

13 pages, 6838 KiB  
Article
Preparation and Bonding Properties of Fabric Veneer Plywood
by Ziyi Yuan, Limei Cheng, Chengsheng Gui and Lu Fang
Coatings 2025, 15(8), 864; https://doi.org/10.3390/coatings15080864 - 23 Jul 2025
Viewed by 304
Abstract
Fabric veneer panels were prepared using ethylene-vinyl acetate copolymer film (EVA) as the intermediate layer and poplar plywood as the substrate. Eight fabrics with different compositions were selected for evaluation to screen out fabric materials suitable for poplar plywood veneer. The fabrics were [...] Read more.
Fabric veneer panels were prepared using ethylene-vinyl acetate copolymer film (EVA) as the intermediate layer and poplar plywood as the substrate. Eight fabrics with different compositions were selected for evaluation to screen out fabric materials suitable for poplar plywood veneer. The fabrics were objectively analyzed by bending and draping, compression, and surface roughness, and subjectively evaluated by establishing seven levels of semantic differences. ESEM, surface adhesive properties, and peel resistance tests were used to characterize the microstructure and physical–mechanical properties of the composites. The results show that cotton and linen fabrics and corduroy fabrics are superior to other fabrics in performance, and they are suitable for decorative materials. Because the fibers of the doupioni silk fabric are too thin, and the fibers of felt fabric are randomly staggered, they are not suitable for the surface decoration materials of man-made panels. The acetate veneer surface gluing performance was 1.31 MPa, and the longitudinal peel resistance was 20.98 N, significantly exceeding that of other fabric veneers. Through the subjective and objective analysis of fabrics and gluing performance tests, it was concluded that, compared with fabrics made of natural fibers, man-made fiber fabrics are more suitable for use as surface finishing materials for wood-based panels. The results of this study provide a theoretical basis and process reference for the development of environmentally friendly decorative panels, which can be expanded and applied to furniture, interior decoration, and other fields. Full article
(This article belongs to the Special Issue Innovations in Functional Coatings for Wood Processing)
Show Figures

Graphical abstract

9 pages, 1699 KiB  
Article
Density and Modulus of Elasticity (MOE) Distribution and Grading of Flattened Bamboo Boards
by Xun Luo, Jiarui Xu, Yuquan Li, Zhiru Song, Zhen Jiang, Xiubiao Zhang, Chunping Dai, Hu Miao and Huanrong Liu
Forests 2025, 16(7), 1163; https://doi.org/10.3390/f16071163 - 15 Jul 2025
Viewed by 302
Abstract
The standardization of physical and mechanical properties is critical for the large-scale application of engineered bamboo products. In this study, the distribution characteristics of density and modulus of elasticity (MOE) were systematically examined in a large sample of flattened bamboo boards. The density [...] Read more.
The standardization of physical and mechanical properties is critical for the large-scale application of engineered bamboo products. In this study, the distribution characteristics of density and modulus of elasticity (MOE) were systematically examined in a large sample of flattened bamboo boards. The density and MOE ranged from 0.46 to 1.12 g/cm3 and 5.60 to 22.18 GPa, respectively. Both exhibited a decreasing trend with increasing board thickness. Based on interquartile analysis, four density grades and five MOE grades were established. A strong positive correlation was identified between density and MOE, indicating that density—closely linked to fiber volume fraction—is the primary factor influencing mechanical performance. Notably, the graded bamboo boards demonstrated significantly higher modulus values than conventional wood veneers such as hemlock and poplar, highlighting their potential for high-performance structural applications. This study proposes a practical grading framework that contributes to the standardization and broader engineering utilization of flattened bamboo boards. Full article
(This article belongs to the Special Issue Wood Properties: Strength, Density, Hardness)
Show Figures

Graphical abstract

22 pages, 11082 KiB  
Article
Exploring the Impact of Inter-Layer Structure on Glass Fiber-Poplar Composite Board: Mechanical and Thermal Properties Analysis
by Jiong Zhang, Shurui Liu, Jinpeng Li, Jixuan Wang, Haoyu Bai, Peng Wei and Tian Liu
Materials 2025, 18(14), 3284; https://doi.org/10.3390/ma18143284 - 11 Jul 2025
Viewed by 258
Abstract
This study presents the design and fabrication of a glass fiber–poplar veneer composite plate, investigating how varying interlayer configurations of glass fiber (single- and double-layer) and the arrangement of poplar veneer layers (odd and even) impact the mechanical and thermal insulation characteristics of [...] Read more.
This study presents the design and fabrication of a glass fiber–poplar veneer composite plate, investigating how varying interlayer configurations of glass fiber (single- and double-layer) and the arrangement of poplar veneer layers (odd and even) impact the mechanical and thermal insulation characteristics of these composite plates. Compared to plywood made from natural wood, glass fiber significantly improved the properties of fast-growing poplar plywood. The highest impact strength increased by 3.62 times, while the flexural strength increased by 26.22% and the tensile strength by 29.66%. The thermal diffusion coefficient of the experimental group decreased by 40.74%, indicating better insulation. Interestingly, single-layer glass fiber is superior to a double-layer structure in terms of thermal insulation. An optimal interlayer structure was identified, comprising one veneer layer between two layers of glass fiber cloth, repeated three times. Abaqus 2019 was used for finite element analysis (FEA). The simulation results agree with the experimental data to within 5%. These findings confirm the importance of structural configuration in determining the properties of composite materials, providing a theoretical basis for the structural design of fiber–reinforced composite materials. Full article
Show Figures

Figure 1

22 pages, 2033 KiB  
Article
The Mechanical Properties of Laminated Veneer Products from Different Stands of Douglas Fir and Norway Spruce in Germany
by Tobias Krenn, Dirk Berthold, Nina Ritter and Carsten Mai
Forests 2025, 16(7), 1040; https://doi.org/10.3390/f16071040 - 21 Jun 2025
Viewed by 285
Abstract
The relationship between silvicultural strategies, manifested in the thinning method and rotation age on sites with different water supply, and the mechanical properties of engineered wood products plywood and laminated veneer lumber has been analyzed. Sample logs from five German sites of Norway [...] Read more.
The relationship between silvicultural strategies, manifested in the thinning method and rotation age on sites with different water supply, and the mechanical properties of engineered wood products plywood and laminated veneer lumber has been analyzed. Sample logs from five German sites of Norway spruce (Picea abies (L.) Karst.) and Douglas fir (Pseudotsuga menziesii (M.) Franco) have been rotary-peeled and processed into boards with a phenol–resorcinol–formaldehyde adhesive to evaluate their performance under flexural, tensile, and compressive loads. Satisfactory coefficients of determination were reached for Norway spruce in regard to the silvicultural framework and the tree characteristics of slenderness and crown base height. Douglas fir products did not achieve comparable determination due to high variance within boards and stands but did achieve significantly better mechanical properties. Norway spruce was observed to be more responsive to thinning measures, while the effect of different thinning regimes was not evident for Douglas fir. The on-site evaluation of Douglas fir stands for veneer product quality based on silvicultural parameters and tree characteristics was shown to be inconclusive, with its naturally higher wood density being the decisive constant. Full article
(This article belongs to the Special Issue Wood Properties: Strength, Density, Hardness)
Show Figures

Figure 1

14 pages, 959 KiB  
Article
Effective Wood Veneer Densification by Optimizing Key Parameters: Temperature, Equilibrium Moisture Content, and Pressure
by Tolgay Akkurt, Anti Rohumaa and Jaan Kers
Forests 2025, 16(6), 969; https://doi.org/10.3390/f16060969 - 7 Jun 2025
Viewed by 465
Abstract
Due to increasing environmental concerns and the scarcity of high-quality hardwood resources, enhancing wood properties—such as strength, surface smoothness, and impact resistance—has become essential, especially for veneer-based products. Wood densification is a promising method for such improvements, typically involving mechanical, thermo-mechanical, or hygrothermal-mechanical [...] Read more.
Due to increasing environmental concerns and the scarcity of high-quality hardwood resources, enhancing wood properties—such as strength, surface smoothness, and impact resistance—has become essential, especially for veneer-based products. Wood densification is a promising method for such improvements, typically involving mechanical, thermo-mechanical, or hygrothermal-mechanical processes. However, most prior studies examined only one densification parameter at a time. This study systematically investigates the combined effects of equilibrium moisture content (EMC), pressing temperature, and pressure on birch veneer densification. Birch veneers were densified radially using four temperatures (90–210 °C), three pressures (1.8–5.4 MPa), and three EMC levels (5%–20%) for a fixed pressing time of 8 min, resulting in 36 unique combinations. Results showed that higher pressing pressure and higher initial EMC consistently led to greater veneer densification. Optimal outcomes were achieved under two distinct conditions: (1) 90 °C with high EMC and high pressure, and (2) 210 °C with the same high EMC and high pressure. Intermediate temperatures (130–170 °C) were less effective. Temperatures above 200 °C were found critical due to lignin softening beyond its glass transition temperature. These findings highlight the interactive role of key parameters and provide practical guidance for upgrading low-quality veneers into high-performance engineered wood products in a sustainable and resource-efficient manner. Full article
(This article belongs to the Section Wood Science and Forest Products)
Show Figures

Figure 1

19 pages, 2090 KiB  
Article
Plywood Manufacturing Using Various Combinations of Hardwood Species
by Marcus Cordier, Nils Johannsen, Bettina Kietz, Dirk Berthold and Carsten Mai
Forests 2025, 16(4), 622; https://doi.org/10.3390/f16040622 - 2 Apr 2025
Viewed by 583
Abstract
This study evaluates the potential of various hardwood combinations in plywood production in response to increasing wood demand and a changing roundwood supply in Central Europe. Six different combinations of nine-layer plywood were produced using 2 mm rotary-cut veneers from lime (Tilia [...] Read more.
This study evaluates the potential of various hardwood combinations in plywood production in response to increasing wood demand and a changing roundwood supply in Central Europe. Six different combinations of nine-layer plywood were produced using 2 mm rotary-cut veneers from lime (Tilia spp.), Norway maple (Acer platanoides), European hornbeam (Carpinus betulus), Sycamore maple (Acer pseudoplatanus), mountain ash (Sorbus aucuparia), and European beech (Fagus sylvatica) with phenol–formaldehyde adhesive, and they were compared to silver birch (Betula pendula) plywood as a reference. The raw densities of the test panels varied between 0.85 and 1.04 times the reference density (795 kg m−3). Flexural strengths (the modulus of rupture, MOR) ranged from 68 N mm−2 to 104 N mm−2 for a parallel fibre orientation and 44 N mm−2 to 61 N mm−2 for a perpendicular fibre orientation of the top layers. The modulus of elasticity (MOE) ranged from 7160 N mm−2 to 11,737 N mm−2 for the parallel fibre orientation and from 4366 N mm−2 to 5575 N mm−2 for the perpendicular orientation. The tensile shear strength varied between 0.91 and 1.69 times the reference (1.49 N mm−2). The thickness swelling after 24 h was higher in all variants than the reference (6.4%), with factors between 1.39 and 1.64. A significant effect was observed when layers with a lower density were arranged on the outside and those with a higher density in the core, resulting in a more uniform density distribution across the cross-section after hot pressing. This created a levelling effect on mechanical and physical properties, especially the modulus of rupture (MOR) and the modulus of elasticity (MOE). Overall, the evaluated hardwood combinations demonstrated comparable properties to the birch reference and industrially produced birch plywood. Full article
(This article belongs to the Special Issue Novelties in Wood Engineering and Forestry—2nd Edition)
Show Figures

Figure 1

18 pages, 5294 KiB  
Article
Multi-Layer Oil- and Water-Resistant Food Containers Made Using Cellulose Nanofibril-Laminated Wood Veneer
by Nabanita Das, Islam Hafez, Douglas Bousfield and Mehdi Tajvidi
Polysaccharides 2025, 6(2), 28; https://doi.org/10.3390/polysaccharides6020028 - 2 Apr 2025
Viewed by 919
Abstract
This work aimed at replacing per- or poly-fluoroalkyl substance (PFAS)-based food-serving containers with wood-based, oil- and grease-resistant food-serving containers. A novel container was developed by laminating wet cellulose nanofibril (CNF) films to both sides of yellow birch wood veneer using a food-grade polyamide–epichlorohydrin [...] Read more.
This work aimed at replacing per- or poly-fluoroalkyl substance (PFAS)-based food-serving containers with wood-based, oil- and grease-resistant food-serving containers. A novel container was developed by laminating wet cellulose nanofibril (CNF) films to both sides of yellow birch wood veneer using a food-grade polyamide–epichlorohydrin additive (PAE) as an adhesive. CNFs significantly improved the wood veneer container’s mechanical strength and barrier properties. The container’s mechanical testing results showed significant increases in flexural strength and modulus of elasticity (MOE) values in both parallel and perpendicular directions to the grain. All formulations of the container showed excellent oil and grease resistance properties by passing “kit” number 12 based on the TAPPI T 559 cm-12 standard. The water absorption tendency of the formulation treated at higher temperature, pressure, and longer press time showed similar performance to commercial paper plates containing PFASs. The developed composite demonstrates superior flexural strength and barrier properties, presenting a sustainable alternative to PFASs in food-serving containers. Both wood and CNFs stand out for their remarkable eco-friendliness, as they are biodegradable and naturally compostable. This unique characteristic not only helps minimize waste but also promotes a healthier environment. If scaled up, these novel containers may present a solution to the oil/grease resistance of bio-based food containers. Full article
Show Figures

Figure 1

15 pages, 3673 KiB  
Article
Veneer Composites for Structural Applications—Mechanical Parameters as Basis for Design
by Robert Krüger, Beate Buchelt, Mario Zauer and André Wagenführ
Forests 2025, 16(4), 617; https://doi.org/10.3390/f16040617 - 31 Mar 2025
Viewed by 281
Abstract
The use of veneer composites as structural components in engineering requires special design. The dimensioning of laminated wood can be optimized by varying the wood species, veneer thickness, orientation, arrangement, number of single layers, and other factors. Composite properties can be calculated using [...] Read more.
The use of veneer composites as structural components in engineering requires special design. The dimensioning of laminated wood can be optimized by varying the wood species, veneer thickness, orientation, arrangement, number of single layers, and other factors. Composite properties can be calculated using suitable model approaches, such as the classical laminate theory. Thus, an optimization can be achieved. The present study verified the adaptability of the classical laminate theory for veneer composites. Native veneer, adhesive-coated veneer, and solid wood were investigated as raw materials for the plywood layers. Mechanical properties were determined using tensile and shear tests and used as parameters to calculate the composite properties of the plywood. The adhesive coating results in an increase in stiffness and strength compared with the native veneer parameters, which is greater perpendicular to the fiber than in the fiber direction. The increase due to the adhesive decreases with increasing veneer thickness. The plywood was bending tested. The measured Young’s modulus was in the range of 8000–10,700 MPa, the shear modulus was in the range of 500–1100 MPa, and the strength was in the range of 70–100 MPa. The values obtained were compared to the calculations. The best prediction of the plywood properties is obtained by using the properties of the adhesive-coated veneer as a single layer. Full article
Show Figures

Figure 1

26 pages, 1128 KiB  
Review
Factors Affecting the Color Change of Monolithic Zirconia Ceramics: A Narrative Review
by Ebru Binici Aygün, Esra Kaynak Öztürk, Ayşe Bilge Tülü, Bilge Turhan Bal, Seçil Karakoca Nemli and Merve Bankoğlu Güngör
J. Funct. Biomater. 2025, 16(2), 58; https://doi.org/10.3390/jfb16020058 - 11 Feb 2025
Cited by 1 | Viewed by 1987
Abstract
Zirconia restorations are widely used in dentistry due to their high esthetic expectations and physical durability. However, zirconia’s opaque white color can compromise esthetics. Therefore, zirconia is often veneered with porcelain, but fractures may occur in the veneer layer. Monolithic zirconia restorations, which [...] Read more.
Zirconia restorations are widely used in dentistry due to their high esthetic expectations and physical durability. However, zirconia’s opaque white color can compromise esthetics. Therefore, zirconia is often veneered with porcelain, but fractures may occur in the veneer layer. Monolithic zirconia restorations, which do not require porcelain veneering and offer higher translucency, have been developed to address this issue. Zirconia exists in three main crystal phases: monoclinic, tetragonal, and cubic. Metal oxides such as yttrium are added to stabilize the tetragonal phase at room temperature. 3Y-TZP contains 3 mol% yttrium and provides high mechanical strength but has poor optical properties. Recently, 4Y-PSZ and 5Y-PSZ ceramics, which offer better optical properties but lower mechanical strength, have been introduced. This review examines the factors affecting the color change in monolithic zirconia ceramics. These factors are categorized into six main groups: cement type and color, restoration thickness, substrate color, sintering, aging, and zirconia type. Cement type and color are crucial in determining the final shade, especially in thin restorations. Increased restoration thickness reduces the influence of the substrate color while the sintering temperature and process improve optical properties. These findings emphasize the importance of material selection and application processes in ensuring esthetic harmony in zirconia restorations. This review aims to bridge gaps in the literature by providing valuable insights that guide clinicians in selecting and applying zirconia materials to meet both esthetic and functional requirements in restorative dentistry. Full article
Show Figures

Figure 1

19 pages, 10551 KiB  
Article
Structure Effects on Mechanical Properties of a Novel Engineered Wood Product: Cross-Laminated-Thick Veneers Based on Infinite Splicing Technology
by Yuxin Yang, Juan Hu, Xinguang Ning, Yahui Zhang, Yingqi He, Yingchun Gong, Wenji Yu and Yuxiang Huang
Forests 2025, 16(1), 181; https://doi.org/10.3390/f16010181 - 19 Jan 2025
Cited by 1 | Viewed by 1018
Abstract
With increasing global concern over carbon emissions in the construction industry, cross-laminated-thick veneer (CLTV) has emerged as an innovative green building material with significant potential to promote the achievement of “dual-carbon” goals. This study developed a groove and tenon splicing technique for thick [...] Read more.
With increasing global concern over carbon emissions in the construction industry, cross-laminated-thick veneer (CLTV) has emerged as an innovative green building material with significant potential to promote the achievement of “dual-carbon” goals. This study developed a groove and tenon splicing technique for thick veneers, enabling infinite splicing of the length direction and the preparation of a large-size CLTV measuring 12 m (length) × 3.25 m (width) × 105 mm (thickness). The mechanical properties of CLTV were studied in relation to splice position, assembly pattern of grain directions, and layer combinations. The results showed that increasing the number of // layers (// or ⊥ indicates grain direction of layer parallel or perpendicular to the length direction of CLTV) and using high-level layers significantly improved the compressive strength and reduced the coefficient of variation of CLTV. In terms of bending properties, reasonable splice distribution, placing // layers away from the neutral axis, and elevating layer level dramatically enhanced CLTV performance. Furthermore, the study revealed the synergistic effect among these design elements. The effects of layer level and the number of // layers on mechanical properties varied depending on splice arrangement and assembly pattern of grain directions, highlighting the importance of efficient structural design and raw material selection. This study addresses the limitations of traditional cross-laminated timber in raw material selection and production efficiency. Through structural innovation, it offers a solution for physical design and performance regulation, enabling the application of larger CLTV in wood structures and presenting new ideas for using fast-growing wood to reduce construction emissions. Full article
Show Figures

Figure 1

19 pages, 2421 KiB  
Article
Antioxidant Particleboards Produced from Forest By-Products with Application in the Food Packaging Industry
by Raquel A. Fernandes, Nuno Ferreira, Sandro Lopes, Beatriz Freitas, Jorge Santos, Jorge M. Martins and Luisa H. Carvalho
Polymers 2025, 17(2), 216; https://doi.org/10.3390/polym17020216 - 16 Jan 2025
Viewed by 844
Abstract
The food packaging industry is one of the fastest growing sectors of our economy, with a large contribution to environmental concerns due to the extensive use of fossil-derived materials. Combining wood-based materials, such as particleboards, with bio-adhesives may offer a great opportunity to [...] Read more.
The food packaging industry is one of the fastest growing sectors of our economy, with a large contribution to environmental concerns due to the extensive use of fossil-derived materials. Combining wood-based materials, such as particleboards, with bio-adhesives may offer a great opportunity to develop sustainable packaging solutions with active antioxidant properties. In the present work, a phenolic extract of poplar bark was produced and bio-adhesives were formulated using citric acid as a cross-linker. The impact of citric acid content on the chemical and bonding properties of bio-adhesives was evaluated. Additionally, the impact of the temperature of curing on their antioxidant capacity was also accessed. The bio-adhesives were applied in the production of particleboards, using poplar veneer particles as raw material. The composite materials exhibit high mechanical resistance, fulfilling the requirement of PB type P1, with remarkable antioxidant activity, opening a possibility to be employed in an active packaging solution. Full article
(This article belongs to the Section Biobased and Biodegradable Polymers)
Show Figures

Graphical abstract

14 pages, 3768 KiB  
Article
Enhancing the Performance of Layered Wood Composites Through the Non-Food Application of Dietary Fiber in Their Bonding Matrix
by Marta Wronka, Anita Wronka and Grzegorz Kowaluk
Appl. Sci. 2024, 14(24), 11780; https://doi.org/10.3390/app142411780 - 17 Dec 2024
Viewed by 939
Abstract
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 [...] Read more.
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. Full article
Show Figures

Figure 1

24 pages, 6889 KiB  
Article
Study on the Smart Dyeing and Performance of Poplar Veneers Modified by Deep Eutectic Solvents
by Yadong Liu and Kuiyan Song
Forests 2024, 15(12), 2120; https://doi.org/10.3390/f15122120 - 30 Nov 2024
Cited by 1 | Viewed by 1291
Abstract
Imitation precious wood materials have become a research focus due to their good quality, high safety level, excellent performance, rich color, varied textures, and high utilization rates. However, their uneven dyeing, poor color stability, and lack of durability limit their further application. This [...] Read more.
Imitation precious wood materials have become a research focus due to their good quality, high safety level, excellent performance, rich color, varied textures, and high utilization rates. However, their uneven dyeing, poor color stability, and lack of durability limit their further application. This study utilized a neural network model optimized with the Gray Wolf Algorithm (GWA) for color matching, using acidic dyes as raw materials and deep eutectic solvents (DESs) for modification. Functional reagents like nano tungsten trioxide (WO3) and titanium dioxide (TiO2) were introduced alongside polyvinyl alcohol (PVA) as a modifier. A dyeing-enhancement modification process was employed to create a poplar veneer that exhibited uniform and stable color performance with a smooth surface, mimicking that of precious wood. Computerized color matching was used to adjust the dye formulation for staining, ensuring stable colorimetric values on the veneer surface, which closely resembled natural precious wood. The average mean squared error in dye concentration prediction, after processing with the Gray Wolf Algorithm and a basic neural network algorithm, decreased from 0.13 to 0.006, ensuring repeatability and consistency in wood dyeing. Analysis and characterization using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and permeability testing revealed that nano TiO2 and WO3 particles were uniformly distributed within the wood cell lumens and firmly bonded. Mechanical testing on PVA-glued veneers showed that compared to untreated poplar veneers, the tensile strength of the imitation wood increased by approximately 62.5%, and the bending strength reached 809.09 MPa, significantly improving the flexibility and tensile properties of the poplar veneer. This study is the first to adopt a DES-modified dyeing-enhancement modification process to improve the dyeing performance, uniformity, durability, and structural stability of wood, showcasing its great potential in architectural decoration, high-end furniture, and artisanal crafts. Full article
(This article belongs to the Section Wood Science and Forest Products)
Show Figures

Figure 1

20 pages, 4299 KiB  
Article
Quality Evaluation of New Types of Core Layers Based on Different Thicknesses of Veneers for Flooring Materials
by Sylwia Olenska and Piotr Beer
Materials 2024, 17(23), 5881; https://doi.org/10.3390/ma17235881 - 30 Nov 2024
Cited by 1 | Viewed by 802
Abstract
Problems with the availability of raw materials on the Polish market have forced wood industry producers to search for new, previously unused species of wood that meet the functional requirements of the target products. Therefore, it is necessary to conduct research on products [...] Read more.
Problems with the availability of raw materials on the Polish market have forced wood industry producers to search for new, previously unused species of wood that meet the functional requirements of the target products. Therefore, it is necessary to conduct research on products whose structure is different from the popular offerings on the market. The goal of this study was to analyze the influence of the thickness of Scots pine veneers, also with Alder interlayer variants, on Young’s modulus and stiffness values of plywood-like composites dedicated to flooring applications regarding statistically based quality control of the products. The variables in this research are the thickness of the veneer, which creates the structure of the base layer of flooring materials, and the kind of wood used. This research looked at basic mechanical properties determining the suitability of flooring materials: modulus of elasticity and stiffness. Because both these parameters describe the product quality, the analyses were based on the normal distribution (containing kurtosis) and the creation of Shewart Control Charts for each parameter. Analyses of control charts provide information on whether the projected production process is stable and is able to give predictable results. In turn, the analysis of the kurtosis value allows us to determine whether Young’s modulus and stiffness values obtained for the products are as close as possible to the values assumed by the manufacturers. The thickness of veneers in the base layer of flooring composites can be enlarged, allowing production to be simplified and more environmentally friendly. New types of layered composites for flooring, manufactured by rotary cutting, without the need for quality assessment, with a minimum number of layers, and additionally verified with Shewart Control Charts, may be applied to production. Presented studies show that veneers of different quality classes, having plywood-like structures, can be used for flooring materials and that the thickness of the veneers in the base layer can be increased. In this way, wood can be used without the need for quality classification and with fewer production processes. Full article
(This article belongs to the Special Issue Engineered Timber Composites: Design, Structures and Applications)
Show Figures

Figure 1

Back to TopTop