Research Articles

Additive manufacturing (AM) using wood-based materials offers new bioeconomic possibilities for sustainable product design and waste valorization. This study examined the influence of wood particle size and shape on the properties of pastes processed by Liquid Deposition Modeling (LDM). Softwood sawdust separated into nine particle size ranges and ground wood powder were analyzed. The materials were mixed with water and methylcellulose as a natural binder, printed into test specimens, and evaluated for shrinkage, density, and flexural strength. Finer particles led to higher densities (up to 0.38 g/cm³), flexural strengths (up to 4.8 MPa), and elastic moduli (up to 436 MPa), while larger particles limited the filler content and reduced mechanical performance. Grinding decreased particle slenderness and promotes greater material density, thereby improving mechanical strength. These findings demonstrate that particle characteristics strongly influence paste printability and mechanical performance, providing a basis for the further development of resource-efficient wood-based materials for sustainable manufacturing.

This study assessed the suitability of four Miscanthus cultivars as alternative raw materials for pulp and paper production. A field evaluation revealed that cultivars 1 and 6 achieved the highest biomass yield ratios, at 2.4 and 2.0, compared to Miscanthus x giganteus. Chemical characterization identified cultivar 6 as favorable for pulping, exhibiting low extractives (1.35%), Klason lignin (14.5%) and moderate ash contents (1.37%). Pulp yields of up to 61.5% were achieved by soda pulping at 160 °C for 90 min and the addition of 15% NaOH by weight of the raw material. Cultivar 23 had the lowest residual lignin content at 1.1%. After refining to 500 PFI revolutions, sheets (30 gsm basis weight) produced from cultivar 6 achieved a tensile index of 43.9 N·m/g. The same tensile index as eucalyptus (44.0 N·m/g) was exhibited after 3000 rotations in the PFI mill. Overall, the results demonstrated that the selected Miscanthus cultivars, especially cultivar 6, is a promising source of fiber, particularly for products that require high absorbency and strength.

Using polylactic acid (PLA) and nanocellulose (NFC) as raw materials, and glycidyl methacrylate (GMA) as the modifier, the PLA/NFC-GMA composite was prepared by solution blending. The addition of GMA effectively improved the dispersion of NFC in PLA, with NFC being grafted onto the PLA molecular chain through a reaction with GMA. The tensile strength of PLA/NFC-GMA composites increased with NFC loading, while GMA improved interfacial compatibility and dispersion, leading to a non-monotonic strength trend and reduced elongation at break. The PLA/NFC-GMA composite with 0.7 wt.% NFC and 6.0 wt.% GMA had the best mechanical properties, with the tensile strength of 27.7 MPa and the elongation at break of 78.4%. The PLA/NFC-GMA composite exhibited excellent UV shielding. Its transmittance was nearly zero below 280 nm and it maintained high transparency within the wavelength range of 400 to 800 nm, with a transmittance exceeding 85%. The transparency of the composite reached its maximum when the NFC and GMA loadings were 0.7 and 1.5 wt.% relative to PLA, respectively. GMA significantly enhanced the thermal stability of PLA/NFC-GMA composites. The thermal stabilization effect of GMA became saturated at ~3.0 wt.%, beyond which additional GMA primarily promoted more complete volatilization without further improving thermal resistance.

The nirai is a four-string hybrid instrument that combines characteristics of the Okinawan sanshin with those of a standard guitar, developed by the brand K. Yairi. Designed for ease of performance, the instrument employs a default open-fifth tuning in the key of G (G2–D3–G3–D4, from the fourth to the first string). Owing to its non-standard tuning and simplified design, conventional Western notation systems-such as standard guitar tablature-are less commonly applied. As a result, performers typically rely on aural learning or adapt musical materials to suit the instrument’s tuning, which yields a diatonic rather than a fully chromatic scale. Knowledge is generated through the act of composing, arranging, and performing original musical works as research artefacts. The research methods include the development of customized notation scores specific to nirai, as well as duet performances with selected local traditional instruments. The findings demonstrate that the timbral and modal characteristics of the Nirai integrate effectively with indigenous Bornean instruments, the sape, revealing its potential as a mediating tool for intercultural musical dialogue. This study contributes practice-led insights into alternative tuning systems, compositional strategies, and notation approaches, reinforcing the value of creative practice as a mode of musical knowledge production.

Acoustics plays a significant role in the classification of a wide range of products in wood science and technology, from standing trees to structural elements. The study of wood acoustics involves the use of mechanical waves that are sensitive to several factors, including sample dimensions, intrinsic characteristics of the wood species, and the presence of defects. This study aimed to estimate the modulus of elasticity in juvenile wood of Tectona grandis using three different non-destructive wave-based evaluation methods: ultrasound, impulse vibration, and stress waves, with the goal of identifying the most suitable technique for predicting this mechanical property. Additionally, the study evaluated the impact of knots on wave propagation velocity and, consequently, on the estimation of the modulus of elasticity. Specimens measuring 20 × 20 × 300 mm (width, thickness, and length, respectively) were used, totaling 42 samples divided into two groups: with knots and without knots. The results indicated that all evaluated methods were effective and exhibited strong correlations with the estimated modulus of elasticity. Furthermore, the presence of knots in young, fast-growing teak wood did not significantly influence wave propagation.