Maderas. Ciencia y Tecnología

Effects of design configuration on decay initiation and progression in non-durable wood

2025-12-16T13:51:02+00:00

Wood used above ground and exposed to moisture may be vulnerable to decay. The initiation and rate of decay are influenced by several factors, including substrate type, moisture and temperature. The design and geometry of wood components affect moisture dynamics and may therefore influence both the initiation and progression of decay. This study evaluated the impact of nine different design configurations on the durability of wood components in a field experiment conducted at three North America sites with distinct climates. The tested variables included specimen volume, the presence of impermeable surface coatings, and the arrangement of appressed boards. Significant effects on both decay initiation and severity were observed, with water-trapping features such as appressed boards and sealed surfaces associated with earlier onset and more extensive decay over a fixed period. The results suggest that longer service life may be achieved by avoiding design features that retain moisture or inhibit drying.

Variación anatómica en la madera de clones de Eucalyptus grandis y sus propiedades dinámicas

2026-01-13T19:01:41+00:00

El uso creciente de plantaciones de rápido crecimiento para fines estructurales exige criterios confiables para evaluar la calidad mecánica de nuevos materiales genéticos mediante métodos no destructivos. No obstante, la elevada proporción de madera juvenil y la variabilidad anatómica limitan la interpretación de estas técnicas cuando no se comprende su base estructural.

El objetivo de este estudio fue analizar la variación anatómica de la madera y su relación con la densidad básica y las propiedades dinámicas determinadas por resonancia acústica en cinco clones mejorados de Eucalyptus grandis de 11 años. Se evaluó el espesor y proporción de pared celular, longitud de fibra, ángulo microfibrilar, diámetro y frecuencia de poros, considerando su variación entre clones y dentro del fuste.

Los resultados mostraron que el diámetro y la frecuencia de poros permiten identificar la presencia de madera madura, mientras que la proporción de pared celular explicó la variación de la densidad básica. El ángulo microfibrilar presentó una fuerte relación con la velocidad del sonido y el módulo de elasticidad dinámico.

En conclusión, la integración del análisis anatómico con la resonancia acústica mejora la interpretación de las propiedades dinámico-mecánicas y aporta una herramienta aplicada para la evaluación estructural no destructiva y la selección genética de clones de Eucalyptus

Ajuste de los factores de diseño en compresión axial para madera laminada encolada del álamo

2026-01-15T18:45:12+00:00

La compresión axial en elementos de madera laminada encolada (glulam) requiere de un dimensionamiento preciso que considere tanto las propiedades mecánicas del material como los efectos de esbeltez. En este contexto, los reglamentos vigentes presentan limitaciones al aplicar valores únicos para los factores de estabilidad (C_P) y de inestabilidad (K_c), sin contemplar las variaciones propias de cada especie ni los modos de falla por pandeo. El presente estudio aborda esta problemática mediante barras de madera laminada de Populus deltoides, con el objetivo de ajustar los parámetros “c” y “βc” que intervienen en el cálculo de dichos factores. Se llevaron a cabo ensayos de compresión axial en un total de 320 probetas en el rango de esbeltez comprendido entre 30 a 100. A partir de los resultados experimentales de las tensiones de rotura del percentil 5 % y la resistencia a compresión paralela a las fibras, se determinaron los valores óptimos de los parámetros “c” y “βc”. El reglamento argentino usa un único valor de c=0,9 para piezas de madera laminada encolada de aplicación práctica. Sin embargo, este valor evidencia la necesidad de ajustes para mejorar el dimensionamiento en elementos comprimidos, obteniendo un valor menor de “c”. Por otro lado, el criterio europeo con βc = 0,1 tiende a sobrestimar las cargas de compresión. No obstante, el mayor valor de βc determinado con el programa experimental, presentó una mejor correlación para todas las esbelteces, reduciendo las sobrestimaciones de las cargas a compresión. Los resultados confirman que ajustar los parámetros “c” y “βc” mejora significativamente la precisión del dimensionado y optimizando el diseño en elementos comprimidos.

Decay and leaching resistance of spruce and larch woods treated with preservatives following different incising pretreatments

2026-03-02T22:58:43+00:00

The objective of this study was to determine the extent to which different incising pretreatments can increase decay and leaching resistance of Picea orientalis (oriental spruce) and Larix decidua (european larch) woods. To this purpose, mechanical, biological, and laser incision treatments were applied to sapwood samples of these refractory wood species to enhance permeability. After the incision treatments, cross sections of the samples were sealed with a polyurethane-based paint commonly used in marine applications to minimize excessive uptake of impregnation chemicals. Subsequently, the treated samples were impregnated using a vacuum method with an alkaline copper quat (ACQ) solution (Celcure C₄), a copper (Cu)-based preservative. The impregnated spruce and larch samples with and without different incision treatments were then subjected to leaching. Non-pretreated and non-impregnated samples, pretreated and non-impregnated samples, non-pretreated and impregnated samples (leached and non-leached), and pretreated and impregnated samples (leached and non-leached) spruce and larch were exposed to brown rot (Tyromyces palustris) and white rot (Trametes versicolor) fungi for 16 weeks. The highest Cu content (ppm) in spruce before and after leaching was generally observed in samples treated with laser incision; in larch, the highest values were obtained with biological incision. Moreover, incising treatments did not increase Cu leaching in larch, while only biological incision increased leaching in spruce. Decay resistance against both fungal species generally improved in blocks impregnated with Cu compounds following mechanical and laser incising treatments, both before and after leaching. In addition, leaching reduced decay resistance in the control and in laser incised samples exposed to brown rot fungus.

The utilisation of turpentine and moss oil as epoxy hardeners for bio-based epoxy nanocomposite coatings

2026-03-03T01:20:50+00:00

Despite the growing interest in bio-based epoxy systems, there remains a significant research gap in developing fully bio-derived curing agents that can replace conventional BPA-based epoxy hardeners while maintaining adequate mechanical and physical performance on wood substrates. The objective of this study was to investigate the potential of new bio-based, bisphenol A-free epoxide nanocomposite coatings for wood surfaces, as a replacement for commercially available coating containing bisphenol A. In addition, the surface properties of these coatings were evaluated.

This study involves the use of environmentally friendly, bisphenol A-free, new bio-based epoxy coatings and their nanocomposite derivatives, in which both the resin and hardener are derived from natural sources. The study is original in its use of sustainable natural resources in the coatings industry, as well as in the development of cost effective and readily available systems compared to those derived from petroleum. Futhermore, this

he research is is the first to employ moss oil and turpentine oil as hardeners in epoxy resin curing reactions.

The results obtained with these two oils, which share a similar chemical structure, were compared. The study also investigates the effect of nanoparticles on the physical and mechanical properties of the bio-based coatings. In this study, novel bio-based epoxide nanocomposite coatings for wood surfaces were prepared using a tung oil-based epoxide resin, which was cured with moss and turpentine oil for the first time. Moss oil and turpentine oil were utilised as epoxy hardeners. The wood species selected for this investigation was Fagus orientalis (oriental beech). Furthermore, as prospective substitutes for bisphenol A, the characteristics of the new bio-based epoxide coatings, specifically the system obtained using moss oil and turpentine oil as hardening agent, were evaluated in relation to their nanocomposite derivatives doped with carbon nanoparticles (fullerene, carbon nanotubes, and graphene) for application on wooden substrates. Following the application of various coating materials to the wood surface, evaluations were conducted on the mechanical and physical properties of the wood. This included measurements of water absorption, t oven-dry density, and compression strength parallel to the grain of Fagus orientalis (oriental beech). The findings revealed that all test specimens showed oven-dry density values higher than those recorded for the control group. After the final absorption period, all coated specimens demonstrated a reduction in water absorption compared to the control.. Each coated specimen also exhibited a higher compression strength parallel to the grain than the control group. Consequently, it was established that the implementation of innovative bio-based nanocoatings has the potential to enhance the mechanical and physical properties of Fagus orientalis (oriental beech) wood.

Eco-friendly protection of pine wood using copper nanoparticles biosynthesized from Cleistocalyx operculatus leaf extracts

2026-03-04T13:50:41+00:00

This research investigates the eco-friendly biosynthesis of copper nanoparticles (CuNPs) from Cleistocalyx operculatus (water banyan) leaf extracts for the sustainable preservation of pine wood Pinus kesiya (khasi pine). The study specifically targets protection against common wood-decaying fungi, including Aspergillus flavus ATCC 9643, Fusarium oxysporum ATCC 48112, and Penicillium citrinum ATCC 9849, as well as termites. CuNPs were synthesized under optimized conditions: 80 °C for 30 minutes using a rotary evaporator, at pH 11, with 20 mM copper sulfate, and a 1.5:1 plant extract to precursor ratio. Comprehensive characterization using UV-Vis spectroscopy confirmed a prominent absorption peak at 595 nm. Scanning Electron Microscopy and Transmission Electron Microscopy further validated their spherical morphology, high crystallinity, and an average size of 2 ± 1 nm. Wood durability was evaluated through laboratory tests of fungal and termite resistance To assess the effects of different CuNPs treatments on fungal resistance and termite resistance, a one-way ANOVA was employed. Significant differences were found among the treatment groups (P<0,05). Duncan's multiple range test was performed using SPSS Statistics version 26, with statistical significance set at α = 0,05. The findings demonstrated a clear concentration-dependent efficacy of CuNPs. Treated wood samples exhibited significantly enhanced fungal and termite resistance, displaying notably reduced weight loss (approximately 10-15 %) compared to untreated controls (20-30 %). Furthermore, even at the lowest tested dosage, a substantial termite mortality rate of 43,17 % was observed, highlighting the potent bioactivity of the biosynthesized CuNPs. These results support the potential of Cleistocalyx operculatus-mediated CuNPs as an environmentally sustainable substitute for conventional, often harmful, wood preservatives. This green approach offers a sustainable alternative for wood protection and shows promise for broader applications of eco-friendly nanomaterials.

Image based colorimetric characterization of scrub induced color changes in UV printed and water transfer printed MDF boards

2026-03-05T12:36:31+00:00

Conventional colorimetric evaluation methods remain inadequate for accurately characterizing scrub-induced color changes on UV-printed and water transfer-printed decorative coatings applied to MDF after chemical resistance testing; therefore, this study proposes an image-based colorimetric characterization approach using an Image Processing-Based Scrub Tester to quantitatively assess such changes under simulated domestic chemical exposure. For this study, 8 mm thick Medium-Density Fiberboard sheets with a bright white, polyvinyl chloride-coated Medium-Density Fiberboard, high-gloss acrylic coating Medium-Density Fiberboard, Medium-Density Fiberboard lam, and Medium-Density Fiberboard sheets treated with polyurethane, cellulose-based, water-based and acrylic paints were utilized. A carbon fiber-patterned organic finish was applied to the surfaces of the pre-treated Medium-Density Fiberboard sample using ultraviolet printing and water transfer printing (WTP) techniques, followed by scrubbing testing with various domestic cleaning agents in compliance with Turkish Standards. As part of the picture evaluation process in this study, digital picture of the samples was captured after and before the scrubbing process. Color measurements were then analyzed based on L*, a*, and b* coordinates, conforming to the Commission Internationale de l'Éclairage (CIE L*a*b*) color system, utilizing a newly developed evaluation technique. From the outcomes of the study, it was observed that the overall color shift of the water transfer printing samples was 124,63% more than the ultraviolet printed samples. To assess the precision of the Image Processing-Based Scrub Tester's color measurement system developed in this research, its results were benchmarked against those from a different color tester. As a result, the findings strongly suggest that the color test analysis performed with Image Processing-Based Scrub Tester, together with the developed software, has the potential to serve as an alternative to industrial testing equipment.

Comparative evaluation of three-way mortise-and-tenon joint designs considering mechanical strength and machinability

2026-03-09T23:47:32+00:00

It is still a challenge to manufacture traditional three-way Zongjiao mortise-and-tenon joints using modern CNC-based machines. This study aimed to improve the structure of the Zongjiao mortise-and-tenon joint, a commonly used three-way corner joint in wood furniture, to better align with modern manufacturing practices. First, four improved mortise-and-tenon joint types were designed, and their appearances were evaluated. Secondly, mechanical tests and numerical analyses were conducted to compare the four improved types and two previous types using bending strength and load difference ratio (DR) between the two horizontal members of the joint. Subsequently, the machinability of all types of joints was evaluated through processing time (PT), cutting force (CF), and number of effective programs (NEP). The results showed that the maximum bending strength of the Zongjiao M-T joint was observed in Type D, and the load DR between the two horizontal members was 13,79. The improved Type D has the lowest milling CF of 182 N and the minimum PT of 32 minutes with the least NEP. Through a comprehensive analysis of all the above indices evaluated, it was found that the improved Type D of Zongjiao mortise-and-tenon joint was superior to others, considering appearance, mechanical strength, and machinability. This study provided a paradigm for optimizing wood furniture joints, which can also be applied to other wood products.