Maderas-Cienc Tecnol

Comportamiento mecánico de muros de corte de Eucalyptus grandis: Resultados experimentales versus el criterio de las normas europeas

2023-08-03T14:44:51-04:00

En este artículo se presentan y discuten los resultados de un proyecto orientado a investigar el comportamiento mecánico de muros de corte típicos de construcciones de entramado ligero y construidos con bastidor de Eucalyptus grandis de la Mesopotamia Argentina. La investigación se llevó a cabo sobre 17 paneles, 15 de los cuales integraron 5 series con distintas configuraciones que cumplieron los requerimientos constructivos del Método A del Eurocódigo 5 (AENOR 2016a), y 2 con anomalías. Los ensayos se realizaron según la norma UNE-EN 594 (AENOR 2011). La resistencia al descuadre determinada experimentalmente superó a la obtenida según el Método A en todos los paneles que cumplieron los requerimientos constructivos, ubicando del lado de la seguridad al valor calculado según las reglas europeas. Los resultados experimentales probaron una mayor variabilidad de la rigidez que de la resistencia y mostraron que los paneles que fallaron bajo cargas elevadas no siempre desarrollaron la resistencia esperada para deformaciones admisibles bajo cargas de servicio, indicando la conveniencia de focalizar sobre este aspecto en futuras investigaciones sobre estos sistemas estructurales.

Cross laminated timber bonding quality for different brazilian species and pressing levels

2023-08-03T17:00:38-04:00

The proper choice of raw materials and manufacturing parameters for Cross Laminated Timber is essential to promote the proper bonding of the lamellas, aiming at their application in construction. However, few Brazilian species are currently used in the production of Cross Laminated Timber. The aim of this work was to characterize the bonding quality of four Brazilian reforestation species (Pinus elliottii, Eucalyptus grandis, Toona ciliata and Acrocarpus fraxinifolius) in the manufacture of Cross Laminated Timber with two-component polyurethane adhesive and five different pressure levels (from 0,1 MPa to 1,3 MPa). Bonding quality was evaluated through delamination and glue line shear tests based on the standard EN 14080 (2013). Delamination was affected by the wood species, and the best adhesion occurred for the Cross Laminated Timber manufactured with Pinus elliottii and Acrocarpus fraxinifolius at the bonding pressure of 0,7 MPa. Cross Laminated Timber bonding pressure did not affect the percentage of wood in the shear test fractured surface, whereas higher density Cross Laminated Timber showed higher percentages.

Physical, mechanical, and thermal characteristics of alkaline copper quaternary impregnated oriental beech wood

2023-08-08T17:29:16-04:00

The physical, mechanical, and thermal properties of Oriental beech (Fagus orientalis), which had been impregnated with the water-based, copper-containing Korasit KS material from the Alkaline Copper Quaternary group, were investigated in this study. According to ASTM 1413-07el (2007) standard, the wood samples used in the investigation were impregnated with 3 % and 6 % aqueous solutions of Korasit KS. The modulus of rupture, thermal, and water absorption tests were performed on samples of Oriental beech after they had been impregnated. Oriental beech's modulus of rupture values decreased as a result of Korasit KS impregnation. Additionally, Oriental beech had lower modulus of rupture values at greater concentrations of Korasit KS. In every water absorption period, the water absorption values of the Oriental beech impregnated with Korasit KS were higher than those of the control group. Our results showed that Korasit KS impregnation enhanced thermal properties of Oriental beech. Moreover, higher concentration levels of Oriental beech yielded better thermal characteristics of Oriental beech.

Using acoustic testing to estimate strength and stiffness of wood-polymer composites

2023-08-21T10:24:22-04:00

This study used non-destructive testing with ultrasonic and stress wave propagation to evaluate bending strength and stiffness of wood-polymer composites. Twelve composite plate products were produced with different formulations of polymer matrix (high- and low-density polyethylene and polypropylene) and type and proportion of flour (coconut shell and wood). Mechanical and acoustic properties were influenced primarily by the type of matrix used in the composite. The greater the proportion of wood and coconut shell flour the higher the wave propagation velocity, stiffness, and strength. We found a correlation between mechanical properties (strength and stiffness) and wave velocity and stiffness coefficient. We also present linear regression equations of the stiffness and strength of the specimen as a function of wave velocity and stiffness coefficient obtained through non-destructive testing. For polypropylene and high-density polyethylene matrix composites, the stiffness coefficient provided a better estimate of stiffness, while for low-density polyethylene the wave velocity provided better results.

El bambú Tonkin (Pseudosasa amabilis) como material a explorar en el Ecodiseño. El diseño de un puesto de mercado como caso de estudio

2023-08-08T17:18:06-04:00

El análisis del ciclo de vida (ACV) permite evaluar el impacto ambiental en las diferentes etapas de un diseño/ producto. En el caso de la etapa de selección de materiales, entre las materias primas que tienen un mayor impacto ambiental y alto consumo energético se encuentra el acero. En este contexto, en esta investigación se estudia el uso de Pseudosasa amabilis (bambú Tonkin) como material estructural y estrategia de Ecodiseño, se compara su impacto medioambiental con el del acero en un rediseño de un puesto de mercado para frutas y verduras. Para llevar a cabo el proceso de diseño, se ha trabajado bajo el enfoque de Diseño para la Sostenibilidad (D4S) con la herramienta SolidWorks®, en la que se ha desarrollado el diseño de detalle, incluyendo el estudio del comportamiento estático y ACV, es decir, el estudio de la sostenibilidad de la estructura en el marco del nuevo paradigma de la Economía Circular. Se realizó el rediseño con bambú Tonkin, a partir de un muestreo que arrojó unos datos medios de 30 mm de diámetro y espesor de 6 mm. Los resultados obtenidos, de forma teórico-experimental y con la simulación numérica, confirman que el bambú Tonkin tanto en el análisis de elementos finitos (FEA) como en el estudio de sostenibilidad (ACV), es un material con unas excelentes cualidades estructurales a la vez que tiene un impacto medioambiental mínimo. Es por ello, que se proponen
nuevas líneas de trabajo y se invita a otros grupos de investigación a que se interesen sobre este material verde desconocido.

Quality of Tectona grandis for sawn wood production

2023-08-14T10:02:49-04:00

Forestry companies have invested in genetic improvement to increase wood production in a shorter amount of time. Thus, studies are needed to compare the properties of clonal and seminal wood materials. The objective of this study was to analyze physical and mechanical properties of Tectona grandis from clonal (C1 and C2) and seminal (S) origin and evaluate the yield and quality of sawn wood subjected to outdoor and oven drying. Genetic material was collected from six, 15-year-old trees. Clone C2 presented the lowest amount of bark, and 51 % heartwood up to half the commercial height, while the heartwood of C1 and S went up to 25 % of the height. The three materials did not differ statistically for maximum angular deviation, pith eccentricity, basic density, Janka hardness, anisotropy, commercial income of sawn wood and the presence of knots. After the drying processes, the bowing and crooking indexes were less than 5 mm.m^-1, however, the seminal material showed a higher cracking incidence after outdoor and oven drying. In conclusion, the wood properties of the three materials are similar. In addition, the oven drying process is recommended.

Thinning wood properties of Nothofagus alpina under three different silvicultural conditions

2023-08-25T14:56:33-04:00

The main objective of this study was to assess the properties of Nothofagus alpina wood from thinning that originates from two sites with intensive silviculture and one similar to a secondary growth forest, with different soil, climatic conditions and age. To achieve this, some mechanical, physical and chemical-crystalline properties were characterized; studying the differences from pith to bark and between the selected trees that were taken from the thinning of the three plantations. Among the studied plantation sites, there were statistical differences in equilibrium moisture content, density and modulus of elasticity. Furthermore, FT-IR was able to differentiate the chemical-crystalline compositions from pith to bark and between plantations, while the X-Ray Diffraction showed differences in the crystallinity index. It was possible to differentiate between the sites with a more intense silvicultural intervention and the one with more variable growth conditions.

Fotogrametría SfM de bajo costo para monitorización de ensayos sobre estructuras laminares reticulares de madera deformadas elásticamente a escala real

2023-10-25T16:35:40-03:00

Para validar modelos numéricos de resistencia de estructuras, es necesario medir su deformación bajo carga. La dificultad de dicha medición aumenta con su tamaño y su complejidad. En el presente estudio se determina la geometría de una estructura laminar reticular de gran tamaño tras una prueba de carga. La estructura fue cargada en sus cinco nodos centrales con un peso suspendido de 105 kg por nodo. Se generó el modelo 3D de la estructura sin carga y bajo carga, empleando fotogrametría usando software PhotoModeler Scanner y Metashape. El error máximo en la medida de las distancias sobre la escena fue 1,31 mm, que corresponde al 0,17 % respecto a la diagonal de la base de la estructura. El mayor error medio se dio bajo carga máxima, 0,70 mm de acuerdo a Metashapee y 0,44 mm en PhotoModeler Scanner. El perfil de la estructura bajo carga es coherente con la deformación prevista. La calidad de medida del modelo 3D resultó ser altamente uniforme. Este estudio releva el uso de fotos que han sido tomadas varios años después, a través de la fotogrametría utilizando softwares avanzados.

Influence of thermal pretreatments on dimensional change and humidity sensitivity of densified spruce and poplar wood

2023-09-04T10:13:14-03:00

Densification modification is an effective method to improve many properties of wood. However, den- sified wood is sensitive to humidity and is not dimensionally stable. The effect of thermal pretreatments on the dimensional change and humidity sensitivity of densified Picea orientalis (spruce) and Populus nigra (poplar) wood were investigated. A thermal pre-treatment was applied on the wood specimens at 140 °C, 160 °C, 180 °C, and 200 °C for 7 h and 9 h. Wood specimens were then compressed at ratios of 20 % and 40 % at a temperature of 150 °C. The results showed that spring-back and thickness swelling increased in all specimens (thermally pre-treated and untreated) depending on the increase in compression ratio.

However, set recovery was determined higherat 20 % compression ratio.The equilibrium moisture content values of untreated specimens and thermally pre-treated specimens at low temperatures (140 ºC and 160 ºC) were found lower than uncompressed specimens. The impact of compression ratio on equilibrium moisture content was not clear. Thermal pretreatments significantly affected the dimensional stability and hygroscopicity of densified specimens (especially poplar wood). Depending on the increase in thermal pre-treatment temperature and du- ration, spring-back, set-recovery and thickness swelling in wood specimens decreased up to 31 %, 67 % and 62 %, respectively. In addition, equilibrium moisture content and water absorption decreased with the increase in thermal pre-treatment temperature and duration. Moreover, the thermal treatment temperature was more important than duration on the investigated properties.

Gluing characteristics of Papua New Guinea timber species for various non-structural applications

2023-11-02T14:05:34-03:00

Papua New Guinea (PNG) has abundant natural forest resources but there are many constraints which need to be addressed to support the development of competitive value-added wood industries. There is a need to develop knowledge and capacity in wood science and processing technologies which support successful domestic value-adding wood processing enterprises. A comprehensive testing program has been developed to assess the glue‐bond strength and performance of selected commercial PNG timber species in various cli- matic conditions to simulate service conditions in potential market destinations. Two criteria namely shear strength and wood failure have been used to determine if a species can meet the minimum requirements for either dry use or wet use applications. The performance of 24 different PNG commercial timber species has been assessed using a one-component cross-linking polyvinyl acetate emulsion adhesive. The bondability of the selected species has been carefully estimated considering the wood density and wood moisture content for the strength and durability in dry- and wet-use conditions. The testing results show that as the wood density as a wood property factor and moisture content as a service condition factor increase, high shear strength with high wood failure become more difficult to achieve consistently. The highest shear strength and wood failure results were achieved by softwood plantation species and low-density hardwood species. Based on the testing results, the selected species have been classified into bondability classes (bond very well, bond well, bond with difficulty, very difficult to bond).

Performance of visible and Near-infrared spectroscopy to predict the energetic properties of wood

2023-11-02T16:11:06-03:00

Wood can be used for fuel by direct burning, or as a raw material for other fuels; however, it is necessary to evaluate the energy properties to ensure the optimal use of this material. The most relevant characteristics to be analyzed are the higher heating value, volatile material content, fixed carbon content, and ash content. Along with the traditional methods, there are also non-destructive evaluations that are optimized for speed and reliability. Among these methods, visible spectroscopy and near-infrared spectroscopy have been proven to be robust for the prediction of several wood properties. The aim of this study was to evaluate the potential of visible spectroscopy and near-infrared spectroscopy for species discrimination and prediction of higher heating value, volatile material content, fixed carbon content, and ash content for Eucalyptus saligna, Eucalyptus dunnii, and Eucalyptus benthamii woods. For this purpose, multivariate principal component analysis and partial least squares regression were applied to the collected spectra. The principal component analysis satisfactorily discriminated the three species, explaining 99% of the variance of the visible spectroscopy spectra and 73% of that of the near-infrared spectra. The estimation of energetic properties through partial least squares regression was satisfactory for both visible spectroscopy and near-infrared spectroscopies, which presented calibration R² values close to 1 and low errors for all properties studied.

Effects of thermal treatment and weathering in the resistance against termites of a fast-growing pine wood

2023-11-30T09:12:47-03:00

Considering the limited existing literature on the combined effects of thermal treatment and weathering on the resistance of fast-growing pine wood to subterranean termites, this work deals with the resistance against subterranean termites of a thermally treated and weathered fast-growing pine wood. The pine wood was thermally treated at variable temperatures (c.a. 180 ºC, 200 ºC, and 220°C) for 2 h and then exposed to artificial weathering for three months. Chemical, hygroscopic, thermal, mechanical, colorimetric, biological, and morphological characteristics were evaluated. Compared to the untreated wood, as expected, the thermal treatments yielded wood parts with improved thermal, hygroscopic and colorimetric features. The thermal treatment also helped for retaining the thermal stability, volumetric hydrophobicity, color, and roughness of the pine wood exposed to the weathering. Previous changes ascribed to the weathering process did not affect the damages attributed to the termites attack, although that wood treated at 180 ºC presented an increased resistance against the termites deterioration.

Time-moisture superposition principle in creep behavior of white oak with various earlywood vessel locations

2023-11-30T09:39:04-03:00

Creep behavior of wood plays a fundamental role in precision processing of wood. In this work, experi- mental creep tests have been conducted to determine the influence of earlywood vessel location and moisture content on creep behavior of Quercus alba (white oak). Time-moisture superposition principle was applied to predict long-term creep behavior of white oak. Results revealed that both of instantaneous and 45-min strain of specimens increased with the increasing of moisture content and decreased with increasing distance between earlywood vessel belt and load-bearing surface significantly. Additionally, the time-moisture superposition principle was found to have feasibility to predict creep behavior of white oak with various earlywood vessel locations and moisture content ranges (6 % - 18 %). We believe that the proposed investigation was beneficial for the processing precision and civil engineering applications of wood.

Biosorption of methylene blue and malachite green from single and binary solutions by Pinus pinaster bark

2023-11-21T20:13:44-03:00

Aiming to develop a sustainable separation process reducing the water pollution, in this work Pinus pinaster (cluster pine) bark from a wood veneer industry was used for methylene blue and malachite green removal from aqueous systems. For single adsorption, the influence of time (up 8 h), adsorbent dose (2,5 - 5- 10 g·L-1), temperature (25 ºC - 40 ºC - 60 ºC), pH (2 - 4 - 6) and particle size (0,1 mm - 0,5 mm, 0,5 mm - 1 mm and 1,6 mm - 2 mm) on adsorption was investigated. To study the initial concentration effect on binary adsorption, different concentrations (0 - 5 - 25 - 50 mg·L-1) were used at 25 ºC, natural pH and a dose of 5 g·L-1. High efficiency was obtained at pH = 4 (natural pH), dose of 5 g·L-1 and particle size of 0,5 - 1 mm.

Adsorption percentages higher than 70 % were reached in less than one hour, with removal almost complete at equilibrium in single systems, without temperature influence. Methylene blue was slightly better adsorbed b ybark. In binary systems, dyes exhibited competitive adsorption, decreasing their removal, especially increasing the ini- tial concentration of the other dye. Dyes adsorption followed the pseudo-second order kinetic model, whereas the Langmuir isotherm explained adsorption equilibria in mono-component systems. High adsorption capac- ities (41,7 mg·g-1 for malachite green and 50,0 mg·g-1 for methylene blue) were obtained at 40 ºC and natural pH indicating that pine bark can be effectively used as biosorbent.

Some physical and mechanical properties of Laminated Veneer Lumber reinforced with glass fiber mesh

2023-11-25T07:04:50-03:00

Structural composite lumbers are used extensively in wooden structures. There are many reasons for choosing these materials, including their light weight, easy assemble, and low cost. Various studies have been conducted to increase the load carrying capacities of these materials. Reinforcement with various natural or synthetic fibers is one method that has been studied. In this study, laminated veneer lumber was produced using poplar veneers and glass fiber mesh. One-component polyurethane glue was used in the production of the boards. The modulus of rupture, modulus of elasticity in bending, impact bending strength, and splitting strength values of the control laminated veneer lumber and laminated veneer lumber reinforced with the glass fiber mesh were investigated. In addition, some physical properties such as the densities and moisture contents of the test samples were investigated. Although the reinforcement of laminated veneer lumber using glass fiber mesh had statistically significant effects on impact bending strength, and splitting strength. The effect on the modulus of rupture and the modulus of elasticity in a static bending test was not significant. In addition, the effects of the reinforcement on the densities and moisture contents of the test samples compared the control samples were statistically significant.

Investigation of wood properties and resistance of 25-year-old Gmelina arborea wood selected from crown region to termite attack

2023-11-30T09:54:26-03:00

Gmelina arborea is widely planted and produces many useful products. However, the upper portion of the stem might be useful for some practical applications if properly managed and harvested. In order to explore the potential of this residues, this study investigated the physical, mechanical properties, and resistance of 25-year-old Gmelina arborea (gamhar) wood from the crown region to termite attack. This is with a view to enhance the use of harvesting residues of Gmelina arborea (gamhar) such that the wood in the crown region is used as the main trunk in various applications. The following wood properties including density, modulus of elasticity, modulus of rupture, and compression strength were investigated on crown wood of 25-year-old Gmelina arborea (gamhar). This study compared with results obtained from previous studies for the bole. Test for the natural resistance of the crown wood was carried out at the timber graveyard where the samples were exposed to termites for 10 weeks to determine the weight loss. The wood samples were rated weekly according to the America Standard of Testing Material. Our results showed that there were significant differences in the density of the crown wood of the three selected 25-year-old Gmelina arborea (gamhar) stands. The results for the mechanical properties of the crown wood of the three selected 25-year-old Gmelina arborea (gamhar) trees showed that there were significant differences in the compression and modulus of rupture of the wood samples from the crown region while there was no significant difference in the modulus of elasticity among the selected stands. Visual rating results showed that termite attack ranged from moderate to heavy attack, while the weight loss was not significantly different among the sampled trees. This study has shown that the den- sity and mechanical properties of the crown wood are comparable to those from the trunk. Hence, the crown wood can be used in application as the stem wood. Also, the study has shown that wood from crown region of Gmelina arborea (gamhar) are prone to termite attack and non-durable as the wood obtained from the stem. Therefore, there is a need to apply treatments that can improve its durability and enhance its service life.

Mechanical characterization of visually graded boards from turkish fir and black pine by nondestructive and destructive tests

2023-11-30T00:16:02-03:00

For the mechanical characterization of Turkish fir and black pine, 400 board specimens with 22 mm× 50 mm × 420 mm were visually graded according to TS 1265 standard. Nondestructive tests were here upon performed using the stress wave method. After specimens were intentionally tested under flatwise bending to research the applicability as an alternative to tension and edgewise bending tests in European strength grading system. According to analyses of variance, the mean values of MOR and MOE differed in four groups at a p<0,05 significance level for visually graded boards. High correlations were found between MOR-MOE (R2=0,837) for fir and MOR-MOE (R2=0,776) for black pine. In addition, correlations of MOR-Knot rate for fir and black pine were respectively R2=0,669 and R2=0,660 showing the effectiveness of flatwise bending tests with the visual grading standard. For nondestructive tests, the mean values of the dynamic modulus of elastici- ty were very close in between fir and black pine grades while the usage of defect-free density performed better than the density of the whole specimen. Higher strength classes were found for black pine boards (Class 1= C40, Class 2= C27 and Class 3= C22) compared to fir boards (Class 1= C24, Class 2= C22 and Class 3= C18), respectively. Moreover, a simplified nonlinear material model was proposed for numerical modelling, and the results were found in good agreement in terms of the bending stiffness, strength, and deformation capacity of boards especially for class 1 and class 2 in both softwood species.

Assessment of cellulose nanofibers from bolaina blanca wood obtained at three shaft heights

2023-09-28T09:31:10-03:00

This study evaluated cellulose nanofibers from bolaina blanca wood (Guazuma crinita) obtained at different heights of the longitudinal axis of the shaft of trees from a three-and-a-half-year-old plantation. The wood was subjected to pulping, bleaching and subsequent mechanical milling using a Changsha Samy XYQM-2L planetary ball mill to obtain cellulose nanofibers. The product was characterised using analytical techniques: scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy. Additionally, the degree of polymerisation was determined. The effect of longitudinal position on cellulose nanofibers characteristics was evaluated by comparing means using ANOVA and Kruskal–Wallis statistical tests. The yield of cellulose nanofibers production from the high, middle and basal sections was 32,1 %, 33,6 % and 31 %, respectively. The obtained cellulose nanofibers exhibited a significantly larger diameter for the high zone (84 nm) compared with the middle (75 nm) and basal (69 nm) zones; the length remained above the micrometre range. With respect to degree of polymerisation, a decrease was evidenced with respect to the increase in shaft height; the basal zone exhibited a degree of polymerisation of 300, a significantly higher value than the middle and high zones, which exhibited degree of polymerisation of 249 and 211, respectively. The product showed typical cellulose type I polymorphism and crystallinity indexes of 76 %, 93 % and 96 % for the high, middle and basal sections, respectively. Regarding the thermostability of cellulose nanofibers, the maximum degradation rate of cellulose nanofibers occurred between 335 °C and 341 °C, with cellulose nanofibers from the basal area being the most stable. The adsorption of the methylene blue dye on cellulose nanofibers was evaluated; an efficiency > 60 % was found.

Radial compression strength can predict the hydraulic vulnerability of mature Norway spruce sapwood

2024-01-08T15:32:21-03:00

Hydraulic testing of isolated sapwood from mature tree trunks is time-consuming and prone to errors, whereas the measurement of compression strength is a standardized and rapid wood technological applica- tion. In this study, we aimed to analyze if compression stress perpendicular to the grain relates to hydraulic vulnerability of mature Norway spruce (Picea abies) trunk wood with an expected narrow vulnerability range. The sample-set comprised 52 specimens originating from 34 trees harvested in Sweden. Before mechanical testing, the P50, i.e., the water potential resulting in 50 % of hydraulic conductivity loss, was estimated on small sapwood beams employing the air injection method. Compression strength perpendicular to the grain was de- fined as the first peak of a stress-strain curve (peak stress) when the wood is subjected to radial compression. Peak stress ranged between 1,65 MPa and 5,07 MPa, P50 between -2,98 MPa and -1,98 MPa. We found a good correlation between the peak stress and P50 (r = 0,80; P < 0,0001). This provides further evidence that peak stress in radial compression and P50 are both extremely dependent on the characteristics of the “weakest” wood part, i.e., the highly conductive earlywood. We conclude that the radial compression strength is a good proxy for P50 of mature Norway spruce trunk wood.

Total phenolics, tannin contents, antioxidant properties, protein and sensory analysis of Pleurotus ostreatus, Pleurotus citrinopileatus and Pleurotus djamor cultivated on different sawdusts

2024-01-08T15:56:24-03:00

In mushroom cultivation, it is important to be aware of the impact of the growing substrate. This study investigated the cultivation of various oyster mushrooms, including Pleurotus ostreatus, Pleurotus citrinopileatus, and Pleurotus djamor, on different types of wood sawdust. Total phenolic content, condensed tannins, antioxidant activity by ferric reducing antioxidant power assay, protein and sensory evaluations were performed in cultivated oyster mushrooms. Wood sawdust of Fagus orientalis (oriental beech), Alnus glutinosa (alder), Castanea sativa (chestnut), and Juglans regia (walnut) were used as substrate for studied mushroom type, separately. Because champignon (Agaricus bisporus) was the most consumed mushroom, it was used as control sample. Methanolic extracts of dried mushrooms were used to measure bioactive characteristics. Pleurotus ostreatus samples cultivated in Alnus glutinosa (alder) sawdust substrate had the highest antioxidant activity. The lowest antioxidant activity values were found in Pleurotus djamor cultivated in Juglans regia (walnut) wood sawdust substrate. The highest protein content was measured in Agaricus bisporus as 13,84 %. The other highest protein concentration was found in Pleurotus ostreatus cultivated in Alnus glutinosa (alder) sawdust substrate, at 13,75 %. The lowest protein concentration belonged to Pleurotus citrinopileatus cultivated in Fagus orientalis (oriental beech) sawdust substrate as 9,86 %. While Agaricus bisporus and Pleurotus ostreatus had the highest overall appreciation score, Pleurotus citrinopileatus had the lowest. It has been observed that the substrate content has an important impact on chemical and sensory properties of the oyster mushrooms. This study provides knowledge on the chemical and sensory characteristics of three different Pleurotus mushroom species cultivated on different composts.

Influences of oak utilization on the medium density fiberboard properties

2024-01-08T16:28:56-03:00

Softwoods are the basic and traditional raw materials for medium-density fiberboard production. However, sustainable consumption of wood material in the production of wood-based products requires material variety. Therefore, the usability of hardwood species in the production and its effects on the board properties should be of interest. Considering this, the influence of oak utilization percentages (30 %, 50 %, 70 %, and 100 %) on the physical (density, thickness swelling-TS 2 and 24 h) and mechanical (modulus of rupture, modulus of elasticity, internal bonding, screw holding resistance, and Janka hardness) properties of medium density fiberboard was evaluated in this study. Boards were factory-made instead of laboratory-made using Quercus petraea (oak), Fagus orientalis (beech), and Pinus sylvester (Scots pine) fibers. According to the results, the modulus of rupture, modulus of elasticity, and Janka hardness values were increased when medium-density fiberboard was produced using only oak fiber. On the contrary, thickness swelling, screwholding resistance, and internal bonding properties were decreased.

Improvement of gluing parameters in Edge Glued Panels

2024-01-08T16:55:01-03:00

Faced with the need for innovation and waste reduction that the market demands, the high consumption of adhesive in the furniture industry led to the need and interest in studying ways to reduce this consumption, through changes in the bonding process without compromising the mechanical properties of the bonded ma- terial. The collage is carried out to form Edge Glued Panels of Pinus taeda (loblolly pine), using PolyVinyl Acetate adhesive with an average weight of 205 g/m². If lower weights are used, using the current application method (roller), mechanical strength problems begin to arise. The objective of this work was to study the fea- sibility of applying glue by another method (spray) with weights and, consequently, shorter pressing times, to evaluate the conservation of the mechanical properties of the panels through shear and traction tests. For that, samples were made according to the standards with the current situation of bonding (weight of 205 g/m² and pressing time of 80 s), to obtain reference results in the tests, and in the proposed situations (adhesive weights of 125 g/m² and 80 g/m² and pressing times of 70 s and 75 s), in an attempt to reach the established reference values. Regarding the results, it was feasible to conclude that the current method could be replaced by the proposed one, using the spray together with an adhesive weight of 125 g/m² and pressing times of 75 s and 70 s, with no statistically significant difference for the current method.

Performance characterization of plywood panels bonded with melamine-urea-formaldehyde resin and cellulose nanofibril/borax as an additive

2024-02-09T12:49:20-03:00

In this study, different loading levels of cellulose nanofibril and borax were added as reinforcement in me- lamine-urea-formaldehyde adhesive to enhance the performance properties of plywood panels as engineered wood composites. Physical properties (density, thickness swelling, water absorption, and moisture content), mechanical properties (modulus of rupture, modulus of elasticity, and bonding strength), and formaldehyde content were tested using relevant standards. The results showed that cellulose nanofibril and borax had a synergistic effect, resulting in improved physico-mechanical properties. The best results were obtained by combining 3 % cellulose nanofibril and borax. It was determined that the combination of cellulose nanofibril and borax reinforcement resulted in a significant improvement of around 15 % in the thickness swelling, water absorption, and moisture content of plywood panels. The combination of cellulose nanofibril and borax rein- forcing resulted in a significant increase of around 26 % in the modulus of rupture and modulus of elasticity of plywood panels, with a bonding strength of around 47 %. The reinforcement technique did result in a 34 % decrease in free formaldehyde content. As a consequence, cellulose nanofibril and borax can be used as effec- tive additives in the production of plywood panels to enhance their performance properties.

Densidad y proporción de albura y duramen en nuevos clones de Eucalyptus spp

2024-01-09T00:01:32-03:00

La generación de nuevos materiales genéticos para atender las diversas demandas del mercado de la ma- dera requiere una constante evaluación de sus propiedades tecnológicas. En el presente estudio, se evaluó el contenido relativo de duramen y albura a tres alturas de fuste (0,10 m, 2,80 m y 5,50 m) así como la variación de densidad en dirección axial y radial de clones puros Eucalyptus grandis (rose gum) e híbridos (Eucalyptus grandis (rose gum) x Eucalyptus camaldulensis (red gum) y Eucalyptus grandis (rose gum) x Eucalyptus tereticornis (red irongum)) de 11 años de edad. Los clones puros mostraron un 10 % más de duramen que los híbridos. El material híbrido alcanzó el mayor valor medio de densidades, siendo más homogéneo en el perfil radial y axial. En general, la densidad presentó un patrón creciente en la dirección radial. No se encontraron diferencias significativas en la densidad para las alturas estudiadas en los clones híbridos, mientras que los clones puros presentaron valores de densidad significativamente mayores a 0,10 m. La densidad de la albura fue mayor que la del duramen para las tres alturas de fuste en todos los materiales genéticos. El análisis de los resultados indica que los clones híbridos podrían ser aptos para la producción de pulpa de celulosa debido a la menor proporción de duramen, lo cual facilita el proceso de blanqueo, así como para su uso como madera aserrada o contrachapado estructural por su mayor densidad y homogeneidad en altura.

Characterization of nanocellulose/pyrolysis oil nanocomposite films

2024-01-09T15:05:27-03:00

In this study, the sustainable recycling of tire waste, which is frequently formed in the automotive industry, and the transformation of this recycling into valuable materials are in question. Waste tire pyrolysis oil obtained as a result of the pyrolysis of tire wastes was evaluated for the first time as a reinforcement element in nanocellulose-based nanocomposite films. Nanocellulose was produced using the TEMPO method (2,2,6,6-tetramethylpiperidine-1-oxyl radical). 5 %, 10 % and 20 % pyrolysis oil were added to the nanocomposite films. Thermal (thermal gravimetric analysis, differential scanning calorimetry, thermomechanical (dynamic mechanical thermal analysis and morphological (scanning electron microscopy) characterization of the produced nanocomposite films were performed. The highest thermal stability was observed in the nanocellulose/ pyrolysis oil-20 sample with 20% pyrolysis oil additive. The pyrolysis oil-reinforced nanocomposites resulted in an excellent increase in storage and loss modulus. The storage modulus of the 20 % pyrolysis oil added sample at 100 °C was exactly 18 times that of pure nanocellulose. Nanocellulose-based nanocomposite films with superior thermal properties and structural compatibility demonstrated by characterized results have been shown to be pioneers in future industrial applications such as pharmacy, coating, green packaging.

Evaluation of the mechanical performance of chairs without fasteners constructed of wood–based panels

2023-10-12T21:30:48-03:00

According to the literature review, limited studies were performed related to the production of “without fastener and ready to assemble (RTA)” furniture made of wood-based panel materials with Computer Nu- merical Control (CNC) machines and the evaluation of their strength. The aim of this study was to evaluate the cyclic loading performance of different types of RTA chairs without fastener which produced with CNC machines by using engineering design approach and product engineering methods including performance tests. In the production of chairs, 18 mm thick oriented strand board, medium density fiberboard and Oriental beech plywood were utilized as wood-based panels. Within the scope of the study, 4 different chair types without fasteners were designed and produced, and performance tests were carried out in 3 different loading directions (front to back, back to front and side thrust) with cyclic stepped increasing loading method according to the principles of American Library Association specification. Totally, 108 real size chairs without fastener were prepared and tested. As a result of the study, it was concluded that the chairs produced from Oriental beech plywood gave the best performances, while the chairs produced from medium density fiberboard gave per- formance values close to Oriental beech plywood, except for the side thrust test. However, the mechanical performance values of the chairs constructed of oriented strand board were very low. In conclusion, it could be said that the chairs constructed of Oriental beech plywood and medium density fiberboard without fastener have been found to have sufficient mechanical performance.

Spruce chips stabilization in wood-cement materials: Effect of matrix composition

2023-10-09T22:24:22-03:00

The problem of the presented research is stabilization of spruce chips in modified cement matrix of wood-cement composites and analysing the effect of the stabilisation on selected parameters of these composite materials. The matrix has an impact on the stabilization of the spruce wood content. Silicate ma- trix based on Portland and blended cement was modified by finely ground thermal power plant slag (TPPS) and limestone (LS). Four types of wood-cement composite were subjected to water immersion tests for 28 days. During water immersion, both swelling in thickness and mass changes were analysed. The amount of sugars and pH in leachate were determined after 7 day intervals. Mechanical properties and microstructures were analysed before and after water immersion. Different behaviour with regard to spruce chips stabilization was proved in dependence of wood-cement matrix modification. Differences in thickness, swelling and sugar leach indirectly indicate the influence of the wood-cement composites matrix composition on the stabiliza- tion of spruce chips contained in this matrix. Boards with the matrix modified with thermal power plant slag showed the highest thickness swelling (%) and sugar leaching (0,042 %). Therefore, in the presence of thermal power plant slag modified matrix, spruce chips are more susceptible to sugar leach. The results of strength characteristics confirmed that sugars leached during hydration and after longer contact of wood-cement composites with water have no negative influence in their final properties in the case of all materials tested (reference and modified).

Influence of pretreatment on properties of bamboo portland cement particle board

2023-10-16T23:05:10-03:00

Bamboo contains water-soluble saccharides and carboxylic acid which have an anticoagulation effect on Portland cement, and the anticoagulation ingredients can directly influence the hydration reaction extent. Hydration product varieties and hydration product-bamboo shaving binding interfaces of the Portland cement, and finally the mechanical properties of bamboo cement particle boards. In this paper, bamboo shavings are pretreated by carbonizing treatment, hydro-thermal treatment and alkali treatment; high performance liquid chromatography is adopted to analyze the influences of three different pretreatment methods on contents of water-soluble saccharides and carboxylic acid in the bamboo shavings; a Fourier infrared spectrometer and an X-ray diffractometer are respectively utilized to analyze the characteristic peak changes and crystallization property changes of chemical ingredients of the bamboo shavings before and after the three types of pretreat- ment. This paper discusses effects of three types of pretreatment methods in eliminating water-soluble saccha- rides and carboxylic acid in the bamboo shavings. Bamboo Portland cement particle boards was prepared using bamboo shavings, which are pretreated in three ways, and influences and mechanisms of different pretreatment methods on properties of the bamboo Portland cement particle boards were studied. Research indicates that the mechanical properties of the Portland cement particle board prepared from bamboo shavings pretreated with 3 % NaOH solution are superior to requirements of qualified products and superior products specified in the Standard.

Usability of fractometer for the purpose of a practical preliminary assessment tool for wood density of Pinus brutia

2024-01-12T09:36:07-03:00

The fractometer is a device that breaks increment cores to measure fracture strength. The advantages of the device are that it is relatively fast, easy to use in the field, and it can perform direct strength measurements on increment cores. The main purpose of the study was to evaluate the usability of the fractometer as a preliminary evaluation tool for wood density traits of standing Turkish Pinus brutia (red pine) trees. Fracture strength was measured on 5 mm diameter increment cores, and X-ray densitometry was used for density measurements. Due to the high correlation between the two traits (fracture and density), a model was built using linear regression. Fifty trees were sampled to build the statistical model (r2: 0,74), and an equal sample size was used to test the model. The density value obtained from the model was 0,546 gcm-3, while the density value averaged by the X-ray method for the same group was 0,543 gcm-3. When considering mean values, it can be said that the model provides a good prediction. Based on personal experience and research results, some trees exhibited better growth and wood quality traits than others. Breeding from these trees could offer improvement in tim- ber production and performance for Pinus brutia (red pine). As a general consequence, the fractometer and increment core sampling can be used for pine tree breeding programs for the preliminary assessment of wood density.

Anatomy based papermaking potential of some woody plants under different ecological conditions

2024-01-24T16:35:23-03:00

The increasing use of wood in the forest industry and reduction of forest resources have prompted the pa- per industry to look for new materials. To this end, this study examined the biometric coefficients of the seven woody stems grown in different regions and investigated suitability for papermaking as an alternative to the use of wood. Wood samples of each species were collected from two different regions in Türkiye: the Kozan region, which has a Mediterranean climate, and the Yuvacık region, which has a mostly oceanic climate. The species included in the study were Phillyrea latifolia (mock privet), Arbutus andrachne (greek strawberry tree), Erica arborea (tree heath), Spartium junceum (spanish broom), Laurus nobilis (bay tree), Pistacia tur- pentine (cyprus turpentine tree), and Rhus coriaria (elm-leaved sumac). All fibers were classified as short. The longest fiber was observed for Spartium junceum (spanish broom) in Kozan. The fiber diameter was highest for Arbutus andrachne (greek strawberry tree) from Kozan, followed by Rhus coriaria (elm-leaved sumac) from Yuvacık and Laurus nobilis (bay tree) from Kozan. The fiber dimensions and the relationship between them were statistically analyzed. These included the slenderness ratio, flexibility coefficient, Runkel ratio, rigidity coefficient, Luce’s shape factor, F-factor, and Muhlsteph ratio. Although differences in fiber properties were detected between the two regions, it was determined that these were not enough to affect the desired properties for paper production. It was concluded that the fibers could be used in pulp, paperboard, and corrugated board production when mixed with long fibers.

The effect of adding graphene oxide to urea formaldehyde resin and its efficacy on three layered particleboard

2024-01-24T22:05:34-03:00

The research for improving adhesives and the properties of wood composites is always important for industry. The aim of this study is investigating the effect of adding graphene oxide in the UF resin on the functional properties of particleboard panels with an average thickness of 16 mm. The influence of graphene oxide content (0; 0,25 %; 0,5 % and 0,75 % based on the dry weight of the UF resin) and pressing time (4 and 5 minutes) on the internal bonding, bending strength, modulus of elasticity and dimensional stability were studied. The results showed that the use of graphene oxide in the UF resin caused an improvement of the mechanical and physical properties of the particleboards. Also, comparing two different pressing times, the boards made by 4 minutes with graphene oxide is preferred without negative effect on the functional properties of particleboards.

Evaluation of OSB panels using residual wood with low contents of castor oil polyurethane resin

2024-01-30T10:31:37-03:00

The use of residues from human activities has been currently gaining ground in the national and international markets, aiming toward the production of more sustainable materials that are less aggressive to the environment. Reusing and adding value to new products has also become an important factor in reducing production costs and the best alternative for this is process optimization. The choice for residual balsa wood was due to its rapid growth and low density, as well as for its ease of engineering and determining the ideal amount of resin for different types of panels. This study aims to investigate the influence of the content variation of castor oil-based polyurethane resin on the physical and mechanical properties of OSB board particles made from residual balsa wood in reforestation areas. The panels were produced with 8, 10, and 12 % commercial castor oil-based polyurethane resin and 9 mm long particles; their physical and mechanical characterizations followed international normative recommendations. The results indicated that the panels with resin contents higher than 10 % reached the minimum regulatory requirements for type 2 OSB panels, suitable for structural application. On the other hand, the panels produced with 8 % resin reached the minimum requirements for type 1 OSB panels, suitable for non-structural use by the furniture industry, such as linings and partitions. Therefore, our study concludes that the variation of resin contents for OSB panels of residual balsa wood allowed us to achieve optimal levels for the use of castor oil-based polyurethane resin, reaching minimum values recommended by regulations for OSB panels type 1 and 2 and a great possibility of application of this product for engineered materials.

Relationship between acoustic wave velocity and mechanical properties in Acacia mangium wood

2024-01-31T14:45:40-03:00

There is a strong interest in developing and using acoustic technology to evaluate the mechanical properties of wood in situations where a static bending test is not feasible to undertake. In this study, the mechanical properties of Acacia mangium (black wattle) wood were predicted by using stress wave and ultrasonic wave methods. The values of dynamic modulus of elasticity based on stress wave and ultrasonic wave were 9,29 % and 4,75 % higher than those obtained from static modulus of elasticity, respectively. There was no statistically significant correlation between acoustic velocity and mechanical properties measured by destructive tests. The strong experimental correlation coefficients were found between stress wave and modulus of elasticity (r = 0,94; P < 0,001), and ultrasonic wave and modulus of elasticity (r = 0,83; P < 0,001). This result indicates that stress wave and ultrasonic wave techniques are suitable for predicting the static modulus of elasticity of Acacia mangium (black wattle) wood if the density of the measured elements is known. There was no dependence of wood density and acoustic propagation velocity measured in this study, whereas statistically significant correlations were found between the fiber length with stress wave velocity (r = 0,44; P < 0,05) and ultrasonic velocity (r = 0,48; P < 0,05).

Determinación de la edad de transición de madera juvenil a madura y de sus valores elasto-resistentes en Pinus contorta

2024-02-14T22:42:41-03:00

El porcentaje de madera juvenil en coníferas de crecimiento rápido es un factor determinante de las propiedades básicas, ya que su proporción aumenta a medida que disminuye la edad de rotación. Dicha madera se caracteriza por presentar menor longitud y espesor de pared de traqueidas y mayor ángulo micro-fibrilar, lo cual se traduce en menor densidad y propiedades elasto-resistentes más bajas. Para delimitar la edad transición de madera (juvenil-madura) se realiza el análisis radial de algunas de las características mencionadas. La importancia de establecer dicha edad, radica en la estimación de los volúmenes de ambos tipos de madera, su calidad y potencialidad de uso. El objetivo del trabajo fue determinar la edad de transición y comparar sus valores elasto-resistentes en Pinus contorta (lodgepole). Se trabajó con 9 muestras de 35 años, radios norte y sur para estudios anatómicos, y madera juvenil y madura para ensayos físico mecánicos. Las edades de transición resultaron entre los 12 y 16,5 años, dirección norte y sur, respectivamente. Las variables anatómicas, físicas y mecánicas se diferenciaron significativamente, siendo mayores en la madera madura. A fin de generar una base de datos de esta especie para la región, se sugiere continuar con estudios similares en otros sitios.

Fire performance of Pinus taeda wood treated with zinc borate before and after leaching

2024-03-04T16:06:48-03:00

Owing to its physico-mechanical properties, wood is widely used in housing for both outdoor structures and indoors in floors, ceilings and others. However, its vulnerability to fire makes protection necessary for occupant safety and damage prevention. In this study, the fire performance of Pinus taeda (loblolly pine) wood from northeastern Uruguay treated with zinc borate synthetized in our laboratory is tested. The effect of leaching on zinc borate fire retardant properties was also evaluated. The following parameters associated with the thermal degradation process of wood were analyzed: flame spread, carbonized area, carbonization index and mass loss. The wood was radially and tangentially exposed to the flame in a Vandersall tunnel under controlled conditions for three exposure times: 30, 60, and 80 seconds. The micromorphology of the surfaces exposed to the flame at each exposure time was analyzed with a scanning electron microscope in order to evaluate fiber damage, zinc borate distribution within the wood, and the effects of leaching on fire performance. A clear improvement in the fire resistance of the zinc borate -treated wood could be verified for all exposure times; leaching did not affect its fire retardant properties despite the harsh conditions of the test, making the product potentially suitable for outdoor use.

Biological resistance of thermally modified Gmelina arborea wood

2024-03-19T22:21:17-03:00

Thermal modification of wood is an environmentally friendly method to improve wood durability, mainly against microorganisms. By employing a process similar to the ThermoWood^®, various Gmelina arborea (gamhar) wood specimens were thermally modified at 180 °C, 200 °C, and 220 °C for 3 hours. The effects of the thermal modification process on the resistance to decay by rot-fungi, and attack by subterranean, arboreal, and dry-wood termites were determined. Generally, the thermal modification improved the resistance of Gmelina arborea (gamhar) to decay by Trametes versicolor with increasing process temperature. However, the effect of the process was null on the resistance to biodeterioration by the brown-rot fungus Coniophora puteana and the dry-wood termites Cryptotermes brevis. Even so, the visual damage caused by Cryptotermes brevis was slight. Untreated and thermally modified woods recorded higher resistance to Coniophora puteana than Trametes versicolor. Mass loss caused by Nasutitermes corniger also decreased with increasing thermal modification temperature. According to the visual damage rating values, the attack by Nasutitermes corniger was slight. However, the thermal modification inversely impacted Gmelina arborea (gamhar) attack by Macrotermes sp., as its resistance in the field to the termites decreased with increasing modification temperature. Thus, the thermal modification process contributed to improving the decay resistance of the modified wood to white-rot fungus Trametes versicolor and attack by the arboreal termites Nasutitermes corniger exposed indoors. On the other hand, thermally modified Gmelina arborea (gamhar) wood was very susceptible to Macrotermes sp. in the field. This work would provide a reliable reference document to guide wood industry stakeholders in assessing the performance of untreated and thermally modified Gmelina arborea (gamhar) wood in situations exposed to fungi and termite species adopted.

Influence of rice straw and wood fiber combination on physical and mechanical properties of rice straw pulverized composite board

2024-03-28T09:04:44-03:00

The production of particleboards from various kinds of ligno cellulosic materials are successful on commercial scale in various parts of the country. However, much success is not seen in use of crop residues for particleboards. Rice straw and wheat straw are one such materials that are abundantly available in India that can be used to produce particleboard. The present work investigated the effect of Rice straw particles and wood fibers combination on physical and mechanical properties of the composite board. The pulverized rice straw composite boards were produced with three different composition of rice straw material (100 %, 70 %, 50 %) and wood Fibers (0 %, 30 %, 50 %). Melamine Urea Formaldehyde (MUF), Phenol Cardanol Formaldehyde (PCF), Blocked Isocyanate resin combined with PCF (BPCF), Blocked Isocyanate combined with Urea Melamine Formaldehyde (BUMF) and Blocked Isocyanate combined with PF (BPF) resins were synthesized. The resin system (10%,12%,14%) with requisite additive was admixed with rice straw and wood fibers. According to the resin system employed, the hot press temperature, specific pressure and curing time were worked out for compression of the boards. The boards were produced with 780 - 850 kg/m³ nominal density and prior to testing, the test specimens were exposed to an atmosphere maintained at a relative humidity of 65 ± 5 percent and at a temperature of 27 ± 2 °C until their masses are nearly constant. The boards made were subjected for evaluation of physical and mechanical properties according to IS 3087. It was found that the Rice Straw particles with Wood Fibers of 50-50 combination bonded with PCF and also with MUF adhesive of 12 % resin solids confirms to the requirement of physical and mechanical properties as per IS 3087 particleboards of wood and other lignocellulosic materials (medium density) for general purposes Specification. Comparison with resin for hybrid boards of rice straw particles with wood fiber, BPCF has shown excellent properties than BPF and BUMF. The study indicated that increasing the percentage replacement of wood fibers with rice straw particles by more than 50 % decreased the internal bond strength. It can be concluded that rice straw pulverized particleboard can be successfully made with the combination of 30 % - 50 % wood fibers using PCF resin or BPCF resin.

Contribution of extractives to the bark color of Caesalpinia sappan

2024-04-02T17:27:12-03:00

The purpose of this study was to investigate the contribution of Caesalpinia sappan (sappan wood) bark extractives by analyzing color change of the bark after extraction and the color of the extracts with several color measurement methods. Successive extraction was performed with n-hexane, ethyl acetate, methanol, and hot water. Color change of the bark was measured using CIELab color system and the extracts were analyzed with Ultraviolet-Visible Spectrophotometer, total phenolic content (TPC), and Gas Chromatography Mass Spectrometry (GC-MS). The results showed that the highest change on the bark color after methanol extraction with the Δa* and Δb* values of -2,53 ± 0,60 and -3,64 ± 1,20 respectively. Also, methanol extract showed the highest total phenolic content (860,24 ± 30,19 mg GAE/g). In addition, the Ultraviolet-Visible is analysis showed a peak at 478 nm in the hot-water soluble extract and two peaks in the methanol soluble extract at 396 nm and 478 nm. Hydroquinone was detected as one of the major compounds by Gas Chromatography Mass Spectrometry in the methanol soluble extract. It was suggested that the color of Caesalpinia sappan (sappan wood) bark as well as the deep red coloration of its extract might be contributed by multiple phenolic compounds contained in the methanol extract with hydroquinone as its precursor. Therefore, it is also a potential source for coloring matter.

Assessing the effectiveness of static heuristics for scheduling lumber orders in the sawmilling production process

2024-04-23T16:29:15-04:00

Although optimization models can be used to plan the production process, in most cases static heuristics, such as earliest due date (E), longest processing time (L), and shortest processing time (S), are used because of their simplicity. This study aims to analyze the production cost of the static heuristics and to determine how this cost relates to the size of the production orders in the sawmilling industry. We set a planning problem with different orders and due dates and solved it using two cost-minimization models to compare their solutions. The first was a planning model (PL) where orders were split up into products demand by period, and the second, a planning scheduling (PS) where the sequence of processing orders based on static heuristics was assumed as known. In the latter, the minimum production cost for each static heuristic was found. In both models, the same resource constraints were assumed. The costs showed no significant changes based on order sizes. However, 0,5 % of orders were delayed using PS-E, and 17 % of orders were delayed using PL. PL was an efficient solution method when changing the orders´ size and when looking for the best static heuristic to process the orders. However, PS-E showed the ability to reduce the backlog close to zero while the PL backlog ratio was 17 %. No penalties were applied to backlogs due to their subjective nature; however, when shortages occurred, the demand was unmet or backlogged with substantial costs. Thus, in case the proposed method is adopted using a conservative backlog cost, a sawmill producing under the cut-to-order environment that produces 300000 m³ /year would reduce backlogged orders by 51000 m³. If the holding lumber cost is 2 $/m³, annual savings would be $408000.