Volume 21 Issue 4

Abrasive wear behavior was studied for three tropical hardwood species, Tieghemella heckelii (makore), Khaya anthotheca (mahogany), and Pericopsis elata (assamela), under various normal loads and sliding speeds. Two-body abrasion tests were performed perpendicular to the grain, dry and without lubrication, at sliding speeds of 20 to 70 rpm and under normal loads of 250, 500, and 750 g. The wear coefficient (k) was determined from the slope of the quasi-linear steady-state portion of the wear volume and sliding distance relationship. All species exhibited an initial running-in phase followed by a steady-state wear regime. Makore displayed the lowest average wear coefficients, while assamela exhibited the highest values. Increasing the load from 250 to 500 g reduced the wear coefficient by 32.9% to 36.3%, while the reduction between 500 and 750 g was more moderate (10.1% to 17.5%), indicating a non-linear load dependence. This behavior could be related to variations in actual contact conditions and deformation of the wood’s cellular structure. Sliding speed induced a non-monotonic, species-dependent response, with critical speed ranges corresponding to minimum and maximum wear coefficients. Overall, the results demonstrate that resistance to abrasive wear depends on the combined effects of wood species, normal load, and sliding speed. These results provide useful guidance for selecting tropical hardwoods for applications involving abrasive mechanical contact.

Seashell waste bio-filler in polymeric material composites sustainably improves insulating performance. This study focuses on polyurethane foam composites (PUFc) reinforced with seashell waste powders and the effects of shell type, particle size, and filler loading on physical and mechanical properties and thermal conduction. Oyster, green mussel, and cockle shells were processed into 20, 40, and 80 mesh sizes and integrated into PUF at 10 to 30 wt% using the closed-mold method. Material characterization results shown by X-ray fluorescence analysis revealed calcium carbonate contents of 91 to 96 wt% in all shells. PUF with 20 wt% fillers, at 40 mesh, increased density, hardness, tensile strength, and compressive strength compared with neat PUF. The optimal formulation, oyster shell density (191 kg/m³), and cockle shell achieved a hardness of 86.7 Shore A. Tensile and compressive strengths were 1580 and 1352 kPa, respectively. Thermal conductivity slightly increased with filler additions. The optimal formulation of 20 wt% at 40 mesh oyster shell was 0.0472 mW/mK. However, water absorption increased with increasing filler content and particle size. Scanning electron microscopy-energy dispersive X-ray microstructural observations indicated improved filler dispersion and preserved closed-cell morphology at 20 wt%, 40-mesh filler loadings, values supporting the suitability of seashell-reinforced PUF as a sustainable building insulation material.

This study investigated the relationships between air-dry specific gravity, average annual ring width, and mechanical properties, including bending strength, compressive strength, and shear strength, in seven major coniferous species in Korea: Pinus densiflora, Pinus koraiensis, Larix kaempferi, Pinus rigida, Pinus rigida × taeda, Chamaecyparis obtusa, and Cryptomeria japonica. Specimens were tested according to KS standards, and correlation and regression analyses were conducted for each species. The results showed that air-dry specific gravity had significant positive correlations with mechanical strength in most species, indicating that it is the most reliable predictor of strength. In particular, Larix kaempferi, Pinus rigida, and Pinus rigida × taeda exhibited relatively clear positive correlations with bending, compressive, and shear strengths, confirming that air-dry specific gravity serves as a key indicator for explaining the strength properties of these species. Average annual ring width generally showed negative correlations with bending and compressive strengths; however, the statistical significance varied depending on species and growth region. Therefore, for analyzing the mechanical properties of domestic coniferous wood, air-dry specific gravity should be used as the primary predictive factor, while average annual ring width and species-specific wood characteristics should also be considered.

Traditional patterns are visual carriers of cultural heritage, and understanding young adults’ aesthetic preferences and visual attention may inform contemporary dissemination. This study examined, at the category level and individual sample level, subjective evaluation and objective behavior among 30 university students from one setting in response to 26 traditional wooden furniture patterns of the She ethnic group in eastern Fujian, using preference evaluation questionnaires, semantic differential ratings, and eye tracking. Results showed that (1) subjective evaluation was multidimensional: plant patterns received the highest category-level average (Avg.) score for aesthetic preference (Avg. = 1.811), whereas the Round Longevity Pattern in the abstract patterns performed best at the individual sample level (Avg. = 2.133); (2) Friedman tests showed significant differences in fixation count (FC) at both levels (p < 0.001), with the highest FC for human-figure patterns at the category level (Avg. = 22.950), and the Panhu Pattern at the individual-sample level (Avg. = 28.867); (3) aesthetic preference and visual attention were generally consistent, but at the participant-by-stimulus level, a negative binomial generalized linear mixed model showed no clear independent association between any subjective dimension and FC. This study supports a subjective-objective approach to traditional pattern perception and cultural dissemination.

Interior wood coatings are routinely viewed at close range and encountered by homeowners and employees, making their appearance, durability, and potential effects on indoor health especially important. Many of the wood surfaces in indoor spaces are protected by clear coats, thereby revealing the wood grain patterns. This article reviews published information about interior wood coatings, with emphasis on appearance, health aspects, and protection of the wood. The stability of the color of indoor wood, especially with unpigmented coatings, can be affected by aging, by ultraviolet light coming through windows, and by unintentional spills. Limited ventilation of some interior environments provides a motivation to decrease reliance on volatile organic components of wood coatings, especially during their application. The literature reveals research progress in topics ranging from color and gloss, to durability, and to the minimization of adverse environmental impacts when coatings are used on wood surfaces that are exposed within houses and commercial buildings.

As green consumption and the tea gift market continue to develop, tea packaging is shifting from basic protection toward improved user experience and sustainable use. To address the limited structural utilization and low modularity of existing wooden tea packaging, this study developed a user-needs-driven design approach integrating KANO, AHP, and QFD. User requirements were identified through questionnaires and interviews and classified using the KANO model. AHP was then applied to determine the priorities of requirements, and QFD was used to translate key requirements into design attributes. The results showed that independent module disassembly and reconfiguration, stable connections, adjustable internal space, and post-gifting conversion into everyday storage were high-priority requirements. QFD further identified the interlocking grid structure, multifunctional storage structure, structural stability design, modular dimensional adaptability, and lightweight material reduction as the five highest-ranked design attributes, with relative weights of 21.35, 16.67, 11.35, 11.31, and 10.67, respectively. Based on these findings, a modular wooden tea packaging solution with detachable, replaceable components was developed to enable flexible reconfiguration and functional extension. This study provides a systematic reference for user-needs-driven modular wooden packaging design.

Bound water governs swelling, fiber saturation behavior, and mechanical performance in cellulosic materials. Conventional determination methods, including solvent exclusion and differential scanning calorimetry (DSC), are destructive and labor-intensive. This study shows that near-infrared diffuse reflectance (NIR-DR) spectroscopy provides a mechanistically grounded alternative based on wavelength shifts in the OH combination band near 1.92 µm (≈5210 cm^-1). Rather than relying solely on absorption intensity, the method tracks systematic changes in band position associated with changes in the hydrogen-bonding environment of the cellulose–water system as moisture content changes. A distinct transition in band position occurs at moisture contents consistent with bound water values reported for comparable cellulosic materials. The spectral behavior is interpreted in terms of changes in the ensemble hydrogen-bonding environment within the evolving cellulose–water system. Reinterpreted in light of modern optical transport theory and contemporary cellulose science, the results establish band-position analysis as a physically meaningful, non-destructive approach for assessing bound water in lignocellulosic fibers, with potential application to rapid at-line or in-line measurement and process control.

Coconut coir is an abundant lignocellulosic agro-industrial residue that can be processed into fibrous pulp for exploratory bio-based insulation panels. This study used a complete three-level, three-factor (3^3) factorial design to examine the effects of phosphoric-acid pretreatment concentration, sodium-hydroxide cooking concentration, and bleaching chlorometric degree on gravimetric pulp yield and apparent thermal conductivity. Second-order regression equations and coefficient-magnitude (Pareto) rankings were used as exploratory tools to describe treatment effects, and a genetic algorithm was used to identify a candidate compromise within the tested factor bounds. Observed pulp yields ranged from 20.1% to 74.5%, and apparent thermal conductivity ranged from 0.035 to 0.170 W×m^-1K^-1. The candidate conditions gave model-predicted values of 92.4% pulp yield and 0.041 W m^-1K^-1 apparent thermal conductivity; these values were not independently confirmed experimentally. Because compositional analysis of the recovered solid was not performed, the material is described as treated fibrous pulp rather than purified cellulose. The results provide an exploratory basis for further optimization, which should include composition, moisture, and independent confirmation measurements before practical insulation performance is claimed.

This study investigated the bending creep performance of cork composite wood floorings. The cork composite wood floorings consisted of two temperate species (tulip tree and larch) and two tropical species (teak and merbau) as the face layer, and a cork board reinforced with metal, glass fiber, or carbon fiber as the core layer. The bending creep curves for all specimens showed a shape to increase at the upper right side, and the curves were found to show a linear behavior beyond about 1 h. The initial compliances of cork composite wood floorings increased in the order of merbau (M) < teak (T) = larch (La) < tulip tree (Tu), which showed a density dependence where higher density species that had lower deformation. The creep compliance increased in the order of tulip tree < merbau < teak < larch, but the values of this increase remained small. Regarding the dissimilar materials, the creep compliance tended to increase in the order of CM (cork-metal) < CC (cork-carbon fiber) < CG (cork-glass fiber). From these results, the bending creep compliance of the cork composite wood flooring with temperate wood species was higher than for those with high-density tropical wood species, but the gap between those species was small. These results indicate the potential of temperate wood species for various interior applications.