Research Articles

Increasing global problems and stricter regulation of industrial waste management necessitate a more detailed examination of waste materials. In addition, because of problems such as surface cracking and discoloration of surface-treated materials during use, increasing varnish durability is a popular topic today. In this study, to increase the surface treatment performance, different proportions (2.5%, 5%) of waste marble powder were added into varnishes (water-based and polyurethane varnish) and their effect on surface treatment was evaluated in terms of gloss and oscillatory hardness test. The highest gloss and oscillatory hardness was found in specimens where the marble powder was at a 2.5% level. As the proportion of marble powder in the mixture increased, it had a matting effect. Oscillatory hardness was found to be higher in polyurethane varnish in the radial section. Among the wood species, beech wood exhibited the highest hardness value with polyurethane varnish.

Biomass pellet fuel is one of the alternative renewable energy sources, which has an important place in the fuel market. This article analyses the spontaneous ignition temperature and flash point temperature, which are the most important characteristics for fire risk prediction, especially in the storage. The Norway spruce pellet and experimental pellet with digestate sawdust were tested according to ISO 871: 2010. The novelty of this research is the application of the Setchin Furnace test. The spontaneous ignition temperature for the Norway spruce pellet and the experimental pellet were established as 420 and 450 °C, respectively. The flash point temperature for the Norway spruce pellet was 330 °C and for the experimental pellet 320 °C. The activation energy was higher for the Norway spruce pellet (65.4 KJ.mol^-1) for spontaneous ignition temperature and for the experimental pellet (42.1 KJ.mol^-1) for flash point temperature.

Green synthesis in producing zinc oxide nanoparticles is well known for its ecofriendly nature and acceptable cost. This study determined the effect of pH 6 to 8 on the green synthesis of zinc oxide nanoparticles using brown algae on oil palm empty fruit bunch pulp (OPEFB) and paper substrates. Ten samples including blank samples were prepared. Brown algae extract was prepared followed by preparation of pulp and paper from commercial OPEFB sheets. The brown algae were set at 3 pH levels, 6 (blank sample), 7 and 8. The PU samples underwent handsheet making based on TAPPI Standard T205, while the PA samples were air-dried prior to testing. All samples were analyzed via FESEM, EDX, and XRD, which confirmed that zinc oxide nanoparticles were successfully synthesized on pulp and paper surfaces. It was shown that higher pH levels enhanced the synthesis performance of zinc oxide nanoparticles, and 70 °C was the optimal temperature. The nanoparticles size obtained in this study were 0.27 to 0.54 nm and 0.51 to 1.05 nm for green-synthesized PU and PA samples respectively. Green synthesis was observed to operate better on pulp fiber surfaces rather than paper surfaces.

Synthetic-based furniture varnish (colorless and glossy) was applied in two coats using a brush to the following wood types: lemon (Citrus limon (L.) Burm.), black pine (Pinus nigra Arnold), kotibé (Nesogordonia papaverifera), iroko (Milicia excelsa Welw. C.C. Berg), and loquat (Eriobotrya japonica Lindl.). The color parameters [b*, h^o, L*, a*, and C*, ∆a*, ∆L*, ∆C*, ∆H*, ∆b*, and ∆E*] of the varnished and unvarnished surfaces were compared. The analysis of variance results for all color parameters revealed significant effects for wood type, varnish application, and their interaction. When the ∆E* values derived from color formulas were sorted from the lowest to the highest, they were ordered as follows: lemon, black pine, kotibé, loquat, and iroko. After varnish application, decreases in L* values were observed across all wood types, while increases in b* and C* values were detected. In black pine wood, the a* and h^o values increased. Additionally, for iroko, loquat, and kotibé woods, there was an increase in the a* parameter, while h^o values decreased for these wood types. Overall, the varnish application resulted in color changes in the wood materials.

This study explored methods for integrating intangible cultural heritage (ICH) elements into modern furniture design, using Qianci as an example. Through symbolic semantics analysis, the cultural external layers of form, color, craftsmanship, and composition and the cultural internal layers of symbolic meaning, ideology, religious beliefs, and moral ethics of Qianci symbols were interpreted, extracting core design elements suitable for modern furniture design. Based on the Analytic Hierarchy Process (AHP), a hierarchical model was established to integrate intangible cultural heritage symbols with furniture design, quantitatively analyzing the importance of key elements in the design process. The results indicate that cultural symbolism, form design, cultural element integration, decorative patterns, cultural heritage value, and environmental friendliness are key indicators in furniture design. Accordingly, two thematic furniture design proposals were developed and evaluated, confirming the innovative potential and application value of Qianci symbols in modern furniture design. This study provides new perspectives and practical examples for the revitalization of intangible cultural heritage elements and the diversification of furniture design.

Expansion of the anode coating layer during lithium-ion battery charging and discharging is of significant concern because it can delaminate or break the coating layer, thus critically affecting battery lifespan and the efficiency, especially in silicon-based electrodes. Therefore, control of expansion and improvement of the mechanical properties of the anode layer are essential. Nanofibrillated cellulose (NFC) exhibits excellent network-forming and mechanical properties and have been extensively researched in terms of high-value applications. This study aims to enhance the rheological and mechanical properties of conventional anode layers by using TEMPO-oxidized NFC (TNFC) as the binder. Anode coating processability was investigated through rheological properties, and the interaction mechanisms between TNFC and electrode graphite were explored. Performance changes were examined using tensile and peel tests to assess adhesion between the electrode and copper foil. The tensile properties of an anode with TNFC improved dramatically. The use of TNFC alone as binder reduced the electrode abrasion resistance to copper foil, but this can be countered by combining TNFC with a traditional SBR binder. This study thus highlights the potential of TNFC as novel renewable binders for anodes.

Paper and paperboard are highly regarded for their recyclability and sustainability, but their inherent inhomogeneity presents challenges for material characterization and modeling. Despite being pressed during production, they remain compressible in the thickness direction, making density a key factor in determining mechanical properties. This study examines the effect of density and thickness compression on the in-plane mechanical behavior of paper and paperboard through uniaxial tensile tests on both laboratory paper with different refining energies and commercial paperboard with anisotropy. The results confirm that density significantly affects stress-strain response, elasticity, and plastic deformation. To capture this effect systematically, an efficiency factor is introduced that provides a quantitative measure of the density-dependent mechanical behavior to model the influence of density using a linear function. Incorporating efficiency factors refines the material modeling approach and improves predictions of stiffness and plastic stress. Higher refining energies result in a more homogeneous structure, reducing density-related variations, while commercial paperboard is less affected by fiber orientation and surface coatings. The proposed efficiency factor provides a new framework for optimizing and modelling the influence of the pressure and density on material parameters of fiber-based materials.

Presently, structural grade cross-laminated timber (CLT) panels are manufactured for interior applications. To expand the use of CLT to exterior applications, there is a need to protect the panels from biodegrading agents such as fungi and termites. Pressure treatments are effective methods of increasing the durability of wood and wood-based products. There are limited studies on the influence of micronized copper azole (MCA) treatment on the rolling shear modulus and rolling shear strength of a commercially produced 3-ply southern yellow pine CLT panel Grade V3. It was found that MCA treatment didn’t have a significant effect on the rolling shear strength of the CLT panels, with the rolling shear strength being 2.19 and 2.31 MPa for the untreated and treated CLT panels, respectively. The bonding durability of the CLT panels had mixed results, with the control specimens measuring a significantly lower wood failure percentage (WFP) of 32% as compared to approximately 75% for the MCA treated specimen. The measured block shear strength (BSS) was approximately the same for the treated and the untreated shear block specimen except for one manufacturing group. The average delamination for the treated specimens was 11% while the average delamination for the untreated specimens was 13.2%.

The rapid development of the manufacturing industry has increased the demand for sustainable and efficient logistics solutions. Chip block pallets (CBPs) made from mixed forest group sawdust offer a promising alternative to traditional pallets due to their reliance on lower-cost, renewable materials. This study aims to evaluate the effects of different adhesives, phenol-formaldehyde (PF), urea-formaldehyde (UF), and poly-urea-formaldehyde (PUF), and varying pressing times on the physical and mechanical properties of CBPs. The CBPs were produced using 30, 60, and 90 min pressing times at 180 °C. The results showed that PF demonstrated the highest compressive strength (6.93 MPa) and screw-holding strength (343 N), making it suitable for applications requiring high mechanical performance. The PUF exhibited lower mechanical strength but provided significant environmental advantages with reduced formaldehyde emissions. Meanwhile, UF displayed adequate performance at shorter pressing durations but decreased efficiency with prolonged pressing. Optimal results were achieved at a pressing time of 60 min, which improved physical and mechanical properties while minimizing water absorption. These findings highlight the potential of CBPs as an eco-friendly and effective alternative, with adhesive and pressing parameters tailored to meet specific application requirements.

A flame-retardant treatment for cellulosic paper was applied by spraying the paper with combinations of lignin, phytic acid, and sodium silicate. Lignin enhanced the flame retardancy in the condensed phase, while phytic acid provided dual-phase flame resistance. Sodium silicate further improved thermal stability by forming silica gel through its reaction with phytic acid. The limiting oxygen index increased from 16.8% to 22.0%, and in vertical flame tests, treated paper self-extinguished within 1.5 s, whereas untreated paper burned completely in 12.0 s. Thermogravimetric analysis revealed enhanced thermal stability, with treated paper retaining 36.5% residual char at 900 °C compared to 0% in untreated paper. Despite the relatively low coating coverage from the spray deposition method, the synergistic interaction of phytic acid, lignin, and silica gel effectively compensated by promoting dense char formation and thermal insulation. Fire retardancy was attributed to phytic acid-catalyzed lignin and silica composite formation in the char layer, enhancing structural stability and shielding efficiency. Raman spectroscopy confirmed improved graphitization (I_D/I_G = 1.20), while scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier transform infrared spectroscopy (FT-IR) verified phosphorus and silica retention. This treatment showed potential for high-performance flame-retardant cellulose materials in packaging, construction, and other industries.