Search Results (73)

Eucalyptus nitens (H. Deane & Maiden) Maiden is a widely planted hardwood species in Australia, particularly in Tasmania, where it occupies approximately 168,000 ha. Although primarily managed for pulp production, the species is attracting interest for sawn and engineered wood applications. Previous evaluations of its properties have relied on destructive testing; however, non-destructive evaluation (NDE) techniques provide a viable alternative for industrial applications. This study examined the use of acoustic-based NDE to assess plantation-grown E. nitens logs sourced from two Tasmanian harvesting sites, focusing on the relationship between dynamic modulus of elasticity (DMOE), static MOE, and modulus of rupture (MOR) across radial positions from pith to bark. The results indicated that core samples exhibited stronger correlations with static MOE and MOR compared with middle and outer samples. DMOE consistently overestimated static MOE by 10.81% and 24.66% at the two sites, with variation evident across radial positions. These findings demonstrate the effectiveness of acoustic NDE for evaluating wood stiffness, highlighting the importance of sample location within logs. Full article

The forestry industry, both primary (sawn wood production) and secondary (output of reels, pallets, boxes, cooperage, and tool handles), is growing in importance in Honduras. In 2023, exports from this industry were mainly destined for Central America (58.19%), followed by North America (22.92%) and the Caribbean region (17.20%), with hardly any Honduran wood reaching Asia or Europe. Objective: The goal of this paper is to analyze the current situation of the Honduran timber industry, which is defined by its environmental deterioration caused by the overexploitation of timber resources. Methodology: Using secondary data from official national and international sources regarding the forestry industry in Honduras, we conducted a Welch’s ANOVA analysis added to two post hoc tests (Tukey and Bonferroni), complemented by a linear regression analysis using JASP software, version 0.19.3.0. to carry on our analysis. Findings: The results of our analysis underscore the urgent need to implement a series of public policies in both the medium and short term to strengthen the forestry industry in Honduras. One of Honduras’ greatest strengths is its civil society, particularly its indigenous communities, which are actively working to protect their land from deforestation and soil degradation. If public policies are not implemented in collaboration with private firms to foster the Honduran forest industry cluster, it could lead to significant socioeconomic and environmental consequences. These may include increased pressure on natural forests, rising unemployment, and the loss of an essential income source for forest owners, ultimately exacerbating poverty. Full article

Despite advances in technique and technology, the chainsaw is still the most widely used tool in forestry. For this reason, equipment manufacturers are developing new technical solutions to make working with a chainsaw as easy and efficient as possible. Some examples of this are the development of professional battery-powered chainsaws and the development of new types of saw chains by the leading industry manufacturers. The aim of this paper was to determine the efficiency of the Stihl MSA 300C battery-powered chainsaw equipped with two different types of professional saw chains (Stihl Rapid Super and Stihl Rapid Hexa) when sawing round wood. The efficiency was determined based on measurements of electricity consumption, sawing speed, sawn wood cross-section, and wood chips and dust mass produced during sawing. The second aim was to determine whether there is a difference in measured vibration magnitude between the two tested saw chains. Fresh-fallen European beech (Fagus sylvatica L.) log, approx. 25 cm diameter without pronounced ellipticity, was used for sampling. Results indicate that although the saw chain manufacturer claims the new type of saw chain (Stihl Rapid Hexa) enables greater efficiency of the chainsaw, this was not the case. Results point to a 37% increase in mean sawing time, as well as a 23% increase in energy consumption when using the Rapid Hexa chain, with statistically significant difference (p ≤ 0.05). It should be emphasized that the manual operation of the chainsaw does not allow for a reliable determination of differences in energy consumption caused by changes in saw chain geometry. The advantages of this saw chain are that it is easier to maintain (sharpen) and significantly less wood chips and dust are produced. The measured vibration magnitude shows a statistically significant difference (p ≤ 0.05), i.e., a lower vibration total value on the front handle when using the Stihl Rapid Hexa chain. Full article

The aim of this study was to evaluate the suitability of eight softwood species most commonly used by Greek timber industries, including furniture manufacturers and companies producing roundwood, sawn timber, and plywood. The analysis was based on integrated Multi-Criteria Decision Analysis (MCDA), using a combined approach of the PROMETHEE method and the Analytical Hierarchy Process (AHP), taking into consideration some important criteria that affect timber quality. According to the PROMETHEE complete ranking, Aleppo pine (Pinus halepensis Mill.) achieved the best performance under the selected criteria among the examined softwood species, underlying the importance of Aleppo pine to the Greek timber industry. Our findings could be highly beneficial to the wood industry, promoting the recovery and advancement of the forest sector in general, taking into account that sustainable wood supply is lower than the total biomass available in Europe. Policymakers should prioritize the selection of conifer tree species that can strengthen Greece’s forestry sector, promote sustainable management practices, and increase the economic value derived from the country’s diverse forest resources. Full article

This study addressed multi-product optimization in Cedrelinga cateniformis plantations in the Peruvian Amazon, aiming to maximize volumetric yields of logs and sawn lumber. Data from seven plantations of different ages and types, established on degraded land, were analyzed by using ten stem profile models to predict taper and optimize wood use. In addition, the structure of each plantation was evaluated using diameter distributions and height–diameter ratios; log and sawn timber production was optimized using SigmaE 2.0 software. The Garay model proved most effective, providing high predictive accuracy (adjusted R² values up to 0.963) and biological realism. Marked differences in volumetric yield were observed between plantations: older and more widely spaced plantations produced higher timber volumes. Logs of optimal length (1.83–3.05 m) and larger dimension wood (e.g., 25.40 × 5.08 cm) were identified as key contributors to maximizing volumetric yields. The highest yields were observed in mature plantations, in which the total log volume reached 508.1 m³ha⁻¹ and the sawn lumber volume 333.6 m³ha⁻¹. The findings demonstrate the power of data-driven decision-making in the timber industry. By combining precise modeling and optimization techniques, we developed a framework that enables sawmill operators to maximize log and lumber yields. The insights gained from this research can be used to improve operational efficiency and reduce waste, ultimately leading to increased profitability. These practices promote support for smallholders and the forestry industry while contributing to the long-term development of the Peruvian Amazon. Full article

This paper focuses on analysing the structural performance of fast-grown hardwood versus softwood glued laminated timber (GLT or glulam) beams with the aim to evaluate the potential structural use of the two main species planted in the country. In Uruguay, the first forest plantations date from the 1990s and are comprised mainly of Eucalyptus ssp. and Pinus spp. No one species were planted for a specific industrial purpose. However, while eucalyptus was primarily destined for the pulp industry, pine, which is now reaching its forest rotation, had no specific industrial destination. Timber construction worldwide is mainly focused on softwood species with medium and long forest rotation. The objective of the present work is, therefore, to analyse and compare the potential of eucalyptus (Eucalyptus grandis) and loblolly/slash pine (Pinus elliottii/taeda) to produce glulam beams for structural purposes. Experimental tests were made on sawn timber and GLT beams manufactured under laboratory conditions for both species. The relationship between the physical and mechanical properties of sawn timber showed that, for similar characteristic values of density (365 kg/m³ for pine and 385 kg/m³ for eucalyptus), and similar years of forest rotation (20–25 years for pine and around 20 years for eucalyptus) and growth rates, the structural yield of eucalyptus was higher compared to that of pine. The superior values of modulus of elasticity found in the hardwood species explained this result. Since there is no strength classes system for South American wood species, the European system was the basis for estimating and assigning theoretical strength classes from the visual grades of Uruguayan timbers. For sawn timber, a C14 strength class for pine and C20 for eucalyptus were assigned. Results showed that pine GLT could be assigned to a strength class GL20h, and eucalyptus glulam to GL24h and GL28h, demonstrating the potential of both species for producing glulam beams. Even though eucalyptus showed a better yield than pine, the technological process of manufacturing eucalyptus glulam was more challenging in terms of drying time and gluing than in the case of pine, which derivates in higher economic costs. Full article

Solid wood is renowned as a superior material for construction and furniture applications. However, characteristics such as dead knots, live knots, piths, and cracks are easily formed during timber’s growth and processing stages. These features and defects significantly undermine the mechanical characteristics of sawn timber, rendering it unsuitable for specific applications. This study introduces BDCS-YOLO (Bilateral Defect Cutting Strategy based on You Only Look Once), an artificial intelligence bilateral sawing strategy to advance the automation of timber processing. Grounded on a dual-sided image acquisition platform, BDCS-YOLO achieves a commendable mean average feature detection precision of 0.94 when evaluated on a meticulously curated dataset comprising 450 images. Furthermore, a dual-side processing optimization module is deployed to enhance the accuracy of defect detection bounding boxes and establish refined processing coordinates. This innovative approach yields a notable 12.3% increase in the volume yield of sawn timber compared to present production, signifying a substantial leap toward efficiently utilizing solid wood resources in the lumber processing industry. Full article

This study aimed to assess the financial viability of forest concessions in the state of Pará, Brazil. Two Forest Management Units (FMUs) were analyzed: FMU-2, located in Saracá-Taquera National Forest, and FMU-3, located in Caxiuanã National Forest. Financial indicators were evaluated under different timber productivity scenarios (20 m³/ha and 25.8 m³/ha). At a logging intensity of 20 m³/ha, FMU-2 was not financially viable. However, both FMUs were financially viable at 25.8 m³/ha. Sensitivity analysis demonstrated that FMU-2 requires a logging intensity of over 22 m³/ha and a sawmill yield efficiency of at least 45%. The ideal cost for sawn wood would be USD 226.53/m³, with royalties of USD 16.00/m³. FMU-3 consistently demonstrated positive financial results, despite fluctuations in production costs. The financial viability of investing in forest concessions in state of Pará depends largely on forest productivity, sawmill yield, royalties, and sawn wood costs. Full article

A study was conducted to improve the effectiveness of silvicultural production of structural sawn timber from softwoods. It intends to explore prediction methods for mechanical timber quality. The study material was obtained from six stands divided into age groups of approximately 40- and 80-year-old trees (examining the influence of age). The stands were differentiated by their applied thinning system of thinning from below or above (examining the influence of the thinning system). Resulting from these different levels of data, i.e., stand parameters, tree anatomy, and visual board properties are examined and analyzed in ordinal logistic models and linear mixed models. Visual board properties were discerned by means of the German standard for visual grading of sawn timber. The mechanical board properties were measured in on-edge bending strength tests and allocated into strength classes, which were modeled in dependence of visual characteristics and forestry conditions. The evaluation of mechanical properties attributed a significant loss of timber quality to short rotation periods, non-ideal water supply, and a single-tree management system. The prediction capabilities of models based on site and tree characteristics were on par with the accuracy of visual grading. Management adaptations by intense thinning from above can lead to a significant decline in Norway spruce (Picea abies L.) timber quality when site factors coincide. Particular care should be taken in the management of locations with high yield potential. Non-destructive evaluation based on site characteristics combined with terrestrial laser scan data of tree characteristics has potential as a pregrading method. Full article

Structural lumber is designed to meet the technical standards that ensure safety, cost-effectiveness, and sustainability. However, some tree species face limitations in their growth, which restricts their widespread use. An example of this is Nothofagus alpina, which has excellent mechanical properties but is not utilized much due to the challenges in extracting its timber and poor utilization, mainly because of the length of the wood. There is little information concerned with the uses and better management of small pieces using Nothofagus species, but it is still insufficient. This study investigates the adhesion performance of green-glued finger joints with varying wood ring orientations and moisture contents ranging from 21% to 25% using Nothofagus alpina. The primary aim is to assess how ring orientation and wet timber affect the green gluing process for creating larger wood pieces than sawn wood. The resulting products could meet the standards for wood serviceability number three for native Chilean wood. The findings indicate that finger joint performance improves with higher timber moisture levels. However, the orientation of the wood fibers did not significantly affect the performance under the tested conditions. It is important to note that this effect may become more significant near the fiber saturation point. These findings emphasize the need for a detailed protocol on the green gluing technique for Nothofagus alpina and the associated drying and surface processes in finger joint construction. Full article

This research aims to find suitable processing methods that allow the reuse of wood waste to produce wood waste-based engineered wood logs for construction that meet the strength requirements for structural timber for sawn structural softwood. Three types of wood waste were examined: wood packaging waste (W), waste from the construction and furniture industry (PLY), and door manufacturing waste (DW). The wood waste was additionally crushed and sieved, and the granulometric composition and shape of the particles were evaluated. The microstructure of the surface of the wood waste particles was also analysed. A three-component biopolyurethane adhesive was used to bind wood waste particles. An analysis of the contact zones between the particles and biopolyurethane was performed, and the adhesion efficiency of their surfaces was evaluated. Analysis was performed using tensile tests, and the formation of contact zones was analysed with a scanning electron microscope. The wood particles were chemically treated with sodium carbonate, calcium hypochlorite, and peroxide to increase the efficiency of the contact zones between the particles and the biopolyurethane adhesive. Chemical treatment made fillers up to 30% lighter and changed the tensile strength depending on the solution used. The tensile strength of engineered wood prepared from W and treated with sodium carbonate increased from 8331 to 12,702 kPa compared to untreated waste. Additionally, the compressive strength of engineered wood made of untreated and treated wood waste particles was determined to evaluate the influence of the wood particles on the strength characteristics. Full article

This study aimed to develop a model using experimentally obtained convective heat and mass transfer coefficients to predict the effect of temperature, humidity, and drying rate on wood drying. Tangential wood samples of Eucalyptus nitens (H. Deane & Maiden) were used in the investigation. The experimental design consisted of two temperature levels (40 °C and 55 °C), two relative humidity levels (55% and 75%), and two air velocity settings (2 m·s⁻¹ and 3 m·s⁻¹). The experiments were conducted under a constant evaporation rate, spanning the maximum and critical moisture content in the wood. A statistical model using multivariate regression was created to predict the convective heat and mass transfer coefficients. The results indicated that the experimental data and empirical correlations exhibited an error margin of 37.77% and 37.86%, respectively. A significant positive correlation was found between the convective heat transfer coefficient and air velocity, temperature, and relative humidity, while the convective mass transfer coefficient showed a significant positive correlation only with air velocity and temperature. The model predicted the convective heat and mass transfer coefficients with high accuracy and statistical significance. Using the proposed method, we successfully obtained both convective coefficients, which enable accurate description of heat and mass flow during the convective drying of Eucalyptus nitens wood. Full article

(1) The early assessment of wood quality, even while trees are standing, provides significant benefits for forest management, sales efficiency, and market diversification. Its definition cannot be in absolute terms but must always be linked to the material’s intended use. (2) In this contribution, a review of the scientific literature is given to discuss the visually evaluable attributes that define wood quality in standing trees, the applicability of the techniques used for their assessment, and the effectiveness of these attributes and technologies in predicting quality, to finally highlight future research needs. (3) The visual characteristics generally used to evaluate wood quality are linked to stem form and dimension, branchiness, and stem damage, but their assessment is challenging due to time and resource constraints. To address these challenges, laser-based and image-based techniques have been applied in field surveys. (4) Laser scanners offer detailed and accurate measurements. Photogrammetry, utilizing images to reconstruct 3D models, provides a cost-effective and user-friendly alternative. Studies have demonstrated the effectiveness of these tools in surveying the visible properties of stems and branches, but further development is necessary for widespread application, particularly in software development, with faster and more effective algorithmic advancements for automatic recognition and subsequent measurement of pertinent characteristics being critical for enhancing tool usability. (5) However, predicting wood quality from these surveys remains challenging, with a limited correlation between the visible tree characteristics assessed and the sawn product quality. Empirical studies evaluating products downstream in the forest-wood supply chain could provide valuable insights. In this sense, the implementation of traceability systems could facilitate the linkage between data on standing trees and the quality of the sawn product. Also, further research is needed to develop models that can accurately predict internal tree characteristics and their impact on product quality. Full article

The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of −10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions. Full article

The aim of this study was to analyse the hygienic suitability of wood often used in animal husbandry. To this end, the inactivation of viruses (Enterovirus E as a surrogate for non-enveloped viruses and Newcastle disease virus as a surrogate for enveloped viruses) on germ carriers consisting of various types of wood was studied over an extended period to assess the biosafety of wood as an agricultural building material. The study was designed to assess the intrinsic biocidal activity of the wood itself, without the use of a disinfectant. The laboratory tests were based on German test guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), as well as stainless-steel carriers, were inoculated with enveloped and non-enveloped viruses and stored for up to four months, and the remaining infectivity of the viruses was continuously assessed. The results showed that intact, finely sawn timber with a low depth of roughness had an inactivating effect on the viruses up to 7.5 decadal logarithmic levels. For the non-enveloped virus, inactivation was fastest on Douglas fir wood, with the target reduction for effective inactivation (reduction by factor 4.0 log₁₀) being achieved after two weeks, and for the enveloped virus on pine wood, it was already achieved from the day of drying. The hygienic effects of the wood carriers may be due to their hygroscopic properties and wood constituents. These effects offer potential for further investigation, including tests with other wood species rich in extractives. Full article