Types Of Wood Research Articles

Kualitas Briket Arang Serbuk Limbah Bangkirai, Rengas dan Agathis

Central Kalimantan has many types of wood such as Rengas (gluta sp), Bangkirai (shorea laevifolia endert), and Agathis (agathis spp). The third type of woods are found in the company of furniture as a result of waste in powder form so that it can be utilized for the manufacture of charcoal briquettes. The purpose of the research is to find out the characteristics of charcoal briquettes from wood waste Rengas, Bangkirai, and Agathis which refers to the Indonesian National Standard (SNI 01-6235-2000). The treatment of this research done on Bangkirai wood, Rengas, and Agathis which have different density with 5 replications so that the samples obtained 15 pieces. Data analysis was conducted to determine the effect of the treatment on the character of the studied and if it has significant effect then it is analyzed test difference average middle value that is specified by Coefficient Value of Diversity. Charcoal briquettes testing generally meets Indonesian National Standard (01-6235-2000) on charcoal briquettes except for volatile substances. The research data finding from these three types of wood which examined showed that the type of Bangkirai wood powder has the best charcoal briquette quality because of lower water content is at 5.05%, the higher density is 0.72 g/cm3, the ash content is 1.9% , carbon bound is 63.30%, volatile substance content is 29.75%, press firmness is 41.67kg/cm2, and calorific value is 6958.94 kal/g

Трещинообразование натуральной и модифицированной прессованием древесины березы повислой (Betula pendula Roth): эффект показателя внутреннего трения под влиянием внешних возмущений

Obtaining information about the presence of cracks in raw materials, blanks and wood products is neces-sary to make a decision on the purposes of its subsequent processing and operation. The method for diagnosing cracks in wood is based on measuring internal friction. For prepared samples of natural and modified wood, sawn from the stem part of drooping birch (Betula pendula Roth) trees growing in Khlevensky Forestry, Lipetsk region. (52.184130, 39.110463, ASL 157m), exposed to radial and tangential directions with ultrasound (frequency 24.5 kHz, exposure 0-20 minutes, step 5 minutes) and pulsed magnetic field (strength - 0.3 T, exposure 0-2 minutes, step 0.5 minutes). Next, the internal friction of the samples was studied on an experimental setup by measuring the logarithmic damping decrement based on free-bending vibrations. The absolute values of the dimensionless coefficient of internal friction Q-1, as the main structural parameter for samples of natural and modified wood, were obtained at a significance level of p=0.95: for humidity, in the presence of one crack, Q-1 decreased by 7.04% (D=0.08), in the presence of two cracks - by 8.4% (D=0.15), in the presence of three cracks - by 9.06% (D=0.15); for ultrasound in the presence of one crack Q-1 decreased by 7.17% (D=0.05), in the presence of two cracks - by 8.46% (D=0.05), in the presence of three cracks - by 9.12% (D=0.09); for a pulsed magnetic field in the presence of one crack Q-1 decreased by 7.14% (D=0.05), in the presence of two cracks - by 8.39% (D=0.09), in the presence of three cracks - by 9.02% (D=0.09). When testing the samples of natural wood and pressure-modified drooping birch (Betula pendula Roth) wood, we obtained an asymptotic equation was obtained for ap-proximating the dependence of the decrease in Q-1 on the number of cracks, with the approximation value R2=0.994. The study of the dependence of internal friction on the process of crack formation in various types of wood provides preparation for the next stage - the construction of a prototype system for non-destructive testing of defects.

IRGWP: An international network of key players for a better understanding and industrial developments in wood protection and preservation

IRGWP: An international network of key players for a better understanding and industrial developments in wood protection and preservation

Survey on the natural resistance to decay of five hundred tropical wood species

The natural durability of wood species against rot has again become a matter of interest for the uses of wood as a natural material, while the use of synthetic fungicides is being debated. In the mid-20th century, many experimental studies were performed in Europe and North America, using different standardised protocols. More than five hundred tropical wood species were tested in France between 1955 and 1990, with a total of 9,842 wood samples tested. It would seem useful to allow free access to all the data from these tests in the interests of a more comprehensive study of the natural durability of large wood panels. The great majority (68%) of all these tests used two slightly different protocols with only a change in woodblock test dimensions. Roughly half of the species were tested under one of the two protocols, and the other half under the second. In addition, certain species were tested with both protocols. The dimensions of the test blocks, the fungal strain used, and the wood type (sapwood or heartwood) all give significantly different results, but the mean mass loss due to the 4 main fungal strains is a good predictor of the wood resistance to rot. Overall, mass loss for sapwood with each protocol is 45% higher than for heartwood of the same species. There is a significant positive correlation between the rot resistance of the sapwood and the heartwood, but the decrease in heartwood compared to sapwood is greater in durable wood species than in non-durable ones. Heartwood rot resistance was observed to be highly variable between trees of the same species, except in those classified as “very durable” and “non-durable”. This opens up possibilities for a classification of natural rot resistance for numerous useful types of timber that are often regarded as only moderately resistant because they include a small proportion of species with poor resistance. Each protocol group included over one hundred species for which density and chemical composition data were available. Density, lignin content, and extractive content have a similar and very significant influence on the rot resistance of the wood (R² around 0.25).

The effects of wood fiber directions on bonding performance

Using engineered wood products (EWPs) in the building technologies is very crucial in terms of sustainable approaches. They provide; low weight, high structural stiffness, carbon storage capacity and easy erection on site. EWPs are composite materials that are influenced by a variety of factors that play a critical role in their formation. The chemical ingredients of the wood, the curing process of the adhesive, the type of wood, the relationship between the adhesive and the wood species, the curing temperature, the geometric configuration of the lamellae, etc. can all be included under the heading of these factors. In contrary with massive wood, to obtain EWPs different types of adhesives can be used. Therefore adhesive type and its application method affects the quality of wooden structural element. Choosing the appropriate adhesive is one of the steps to be taken to obtain the structurally correct product. Based on this approach, it was decided to investigate the adhesion performance of different adhesive types. This paper aims to present the best bonding method among the melamine urea formaldehyde (MUF) and epoxy adhesives by considering the fiber directions of the wood and the type of adhesive according to the load. One of the aims of this study is to investigate the effect of changing the fiber direction of wood on adhesion performance, taking into account the current gap in the literature. Pull-off tests were conducted to assess the bonding performance of different types of adhesive in wood samples with varying fiber direction. The wood samples were bonded to the wood surface with varying grain directions. During the pull-off tests, ruptures in the glue line of the test samples were commonly observed. The results have shown that in cylindrical samples bonded with epoxy, the highest bonding strength values were observed in scenarios where the wood fibers were oriented parallel to the load direction and perpendicular to the ground plane. Similarly, for wood samples used as the bonding surface, the highest bonding strength values were achieved when the wood fibers were oriented parallel to the load direction and perpendicular to the surface plane. On the other hand, the highest value in pull-off test setups was found with melamine urea formaldehyde adhesive; commonly used in laminated timber, between the wood samples with grains perpendicular to the load direction and the wood adherence surfaces with a parallel grain direction. In summary, the highest strength value was obtained from the test setup in which epoxy was used as the adhesive and both the wood specimens and the wood bonding surface had fiber directions parallel to the load direction.

Effects of Cutting Parameters and Grain Direction on Surface Quality of Three Wood Species Obtained by CNC Milling

Computer Numerical Control (CNC) machines are increasingly popular in the production of furniture and wood products, because they combine high processing quality with short production time. The effective use of CNC machines depends on the processing parameters, which also affects the quality of the processed surface. The aim of this study was to determine the effect of feed rate, cutting direction, and grain direction on the surface roughness of various types of wood. Three European wood species (oak, beech, fir) were cut with a spindle speed of 16,000 rpm and two different feed rates (5,000 and 10,000 mm/min) using end mill tools on the CNC machine. The milling was performed in two cutting directions (radial and tangential) and two grain orientations (0° and 90°). An analysis of variance (ANOVA) was performed to evaluate the impact of the cutting parameters. The surface roughness measurements were taken, and two surface roughness parameters (Ra and Rz) were measured to determine the surface quality of the wood. According to the results of this study, the lowest surface roughness values, milling with the same processing parameters, occurred for oak wood, while the highest values occurred for fir.

Linkages between intra-annual radial growth and photosynthetic production of four main species in a temperate forest in northeast China

The comprehension of the linkage between radial stem growth and photosynthesis is fundamental to gaining insight into the growth and developmental mechanisms of trees, as well as their adaptive capacity to future climate change. However, such crucial information is rarely available, particularly on short-term temporal scales. In this study, we continuously monitored the intra-annual radial stem growth of a non-porous species (Pinus koraiensis) and three ring-porous species (Quercus mongolica, Fraxinus mandshurica, Ulmus japonica) with monthly measurements in 2019 and weekly measurements from 2020 to 2022(second part in 2022) in a temperate forest of Northeast China based on microcore techniques. Concurrently, we estimated the daily photosynthetic production at the individual tree level using a photosynthetic production model developed by our research team. Subsequently, a generalized linear model was conducted to determine the temporal lag of intra-annual radial stem increment and photosynthetic production. Our results indicate significant differences in the initiation of radial growth among the observed years, while the cessation of growth remained consistent. Specifically, ring-porous species exhibited an earlier onset of radial growth compared to non-porous species, but no consistent pattern was observed for the cessation of growth across different wood types. Additionally, we found a strong coupling between radial growth increment and photosynthetic production without any day lag, particularly in different classes. Furthermore, a notable linear association was observed between relative intra-annual radial growth and photosynthetic production, further indicating a positive correlation between photosynthesis and radial growth. We concluded that the carbohydrates required for radial growth are at least partially derived from photosynthetic production produced on the same day when the leaves were available for photosynthesis. These findings enhance our understanding of the seasonal dynamics of radial growth at the cellular level and provide new insights into the relationship between radial growth and photosynthetic production on short-term temporal scales.

Numerical Evaluation of Transversal Strength of Traditional Fishing Vessel in Penajam Paser Utara, East Kalimantan, Indonesia

Challenges in procuring wood as the primary material for ships have led to a decline in overall quality. Meeting the demands of shipbuilding often involves neglecting consideration for the quality and characteristics of construction materials. Additionally, the shipbuilding process commonly overlooks technical and operational aspects associated with construction specifications. Ship damages frequently result from the selection of wood types, sizes, and ages that do not meet construction criteria or fall below the standards for achieving optimal construction. Many ship constructions are identified that fail to meet the requirements for ensuring the safety and security of the crew, ship, and cargo during operations. This research aims to numerically assess the transverse strength of fishing vessels operating in Penajam Paser Utara using Ansys software. Survey results indicate an average size of fishing boats in this area as 10 – 20 meters in length. 2.6 - 3.5 meters in width, and 1.6 – 2.5 meters in height. The stress analysis results from Ansys Workbench were recorded at 2.3402 MPa

Searching for Optimal Measurement Parameters by Thermogravimetry for Determining the Degree of Modification of Thermally Modified Wood

When wood is thermally modified, several chemical reactions take place that change the chemical and physical properties of the wood. These changes correlate with the degree of modification, which is mostly a function of the temperature and duration of modification, and consequently with the mass loss during this process. There is a lack of standardised quality control to verify the degree of heat treatment of wood and thus its quality. One of the possible methods to check the degree of thermal modification of a particular type of wood is thermogravimetry (TG). It is based on the assumption that processes that did not take place during thermal modification continue when the TG experiment is carried out. In this method, calibration curves have to be established based on TG measurements of standard samples that have been thermally modified at different temperatures and whose mass loss during modification is known. The calibration curves show the mass loss during the TG measurement as a function of the mass loss during the previous thermal modification. The course of thermal decomposition during the TG measurements is influenced by many parameters, such as the mass of the sample, the heating rate, the atmosphere in which the measurement takes place, and the shape of the crucible in which the sample is placed. In this paper, the influence of these parameters on the calibration curves was investigated. We have focused on oak wood. The best parameters result in a calibration curve with the largest correlation coefficient R2 and the highest slope of the line k. On this basis, we can determine the mass loss during the thermal modification of unknown samples of the same wood species under the same measurement conditions.

Study on the Static-Bending Properties of Surface-Reinforced Wood with Asymmetric Fibers

In order to investigate the mechanism of the effect of asymmetric reinforcement on the static-bending properties of wood, this paper tests and analyzes the static-bending properties of SPF wood and seven different types of asymmetric fiber surface-reinforced wood (AFRWC) formed by SPF wood as the substrate and bamboo and carbon fibers as the reinforcement materials. The results of the study found that (1) the moduli of rupture of the seven types of AFRWC were increased to varying degrees, but the static-bending moduli of elasticity increased or decreased; (2) the asymmetric reinforcement changed the cross-section strain distribution and damage type of the wood in static bending; (3) the results of the cross-section strain-field tests and the ABAQUS finite element simulation showed that the asymmetric reinforcement method of bonding the bamboo material and the two layers of CFRP in the compression and tensile zones, respectively, can greatly enhance the static-bending performance of the wood. The error between the simulated and measured values of specimens MOR and MOE is only −0.7% and −7.3%, respectively. This type of asymmetric reinforcement makes it possible to obtain a more reasonable cross-section stress distribution.

Klasifikacija vrsta drva prema slikama uz pomoć dvodimenzionalne konvolucijske neuronske mreže

The woodworking industry’s recognition and classification of timber is essential for trade, production and timber science. Traditional methods of identifying wood types are complex, time-consuming, costly and require expertise in wood science. Traditional techniques have been replaced by convolutional neural networks (CNNs), a deep learning tool to better identify wood species. In contrast to earlier studies that used pretrained models, a novel architecture designed explicitly for the WOOD-AUTH dataset was proposed in this study to develop a new 2D CNN model. The data collection encompasses high-level visual representations of 12 distinct types of timber. It is aimed to create a simpler and faster model as an alternative to time-consuming and heavy wood classification models. Compared to previous studies, this research worked with a newly structured 2D CNN network based on 12 wood species. High accuracy and fast computation time were achieved using fewer numbers (three layers) of the convolutional neural network. The proposed model achieved 94 % accuracy, 87 % precision, 81 % recall, 80 % F1 score and 112 minutes 27 seconds computation time. The 2D CNN model performed better than the transfer learning models regarding training epochs. The primary benefit of the model is its ability to achieve high accuracy with lower computation time, even at high epochs compared to other models. The introduced 2D CNN model produced satisfactory outcomes for wood species classification.

Structural differences of cell walls in earlywood and latewood of Pinus sylvestris and their contribution to biomass recalcitrance.

Scots pine (Pinus sylvestris L.) is an evergreen coniferous tree with wide distribution and good growth performance in a range of habitats. Therefore, wood from P. sylvestris is produced in many managed forests and is frequently used in industry. Despite the importance of pine wood, we still do not fully understand its molecular structure what limits improvements in its processing. One of the basic features leading to variation in wood properties is the presence of earlywood and latewood which form annual growth rings. Here, we characterise biochemical traits that differentiate cell walls of earlywood and latewood in Scots pine. We discover that latewood is less recalcitrant to enzymatic digestion, with galactoglucomannan showing particularly pronounced difference in accessibility. Interestingly, characterisation of lignin reveals a higher proportion of coniferaldehydes in pine latewood and suggests the presence of a different linkage landscape in this wood type. With complementary analysis of wood polysaccharides this enabled us to propose the first detailed molecular model of earlywood and latewood and to conclude that the variation in lignin structure is likely the main determinant of differences in recalcitrance observed between the two wood types in pine. Our discoveries lay the foundation for improvements in industrial processes that use pine wood since we show clear pathways for increasing the efficiency of enzymatic processing of this renewable material. Our work will help guide future breeding of pine trees with desired timber properties and can help link molecular structure of softwood cell walls to function of the different types of xylem in conifers.

INFLUENCE OF ANNUAL GROWTH RING STRUCTURE REGULARITIES AND NATURAL DEFECTS ON PHYSICAL AND MECHANICAL PROPERTIES OF CARPATHIAN SPRUCE

In the process of technical inspection of buildings and structures constructed with the use of both solid logs and Carpathian spruce lumber massively observed processes of deplanation of the wall fence, exit from functional state of constructive elements of inter-storey floors and rafter systems. During inspection calculations of existing construction elements, which are in exploitation for all types of stress-deformed state, there are often questions to the accepted constructive solutions of cross-sections and nodal joints of building structures made of solid wood. This fact can only be due to the discrepancy between the strength and deformation properties of Carpathian spruce and the declared characteristics in normative documents. The presence of natural defects and structural features of the Carpathian spruce structure indicate that the unequal physical and mechanical properties of the two coniferous species that grow in the northern latitudes and the Carpathian region of Ukraine are not entirely true. The distribution of the ratio of latewood to earlywood has a direct influence on the physical and mechanical properties of wood. This fact is caused by rather cellular structure of wood with large annual growth of early and late wood. Such characteristics can have both positive and negative effects on the properties of Carpathian spruce as a building material. This type of wood with a high degree of natural moisture content and cellular structure requires a special pre-drying procedure for the production of building structures. To establish the factual physic-mechanical properties of Carpathian spruce, the current normative documents were analysed and the existing scientific research on this issue was studied. In the process of conducting a comparative analysis of the results of comprehensive studies of standard samples of Carpathian spruce for compression along the fibres and control samples made from the base species - pine, the fact of partial inconsistency of physical and mechanical parameters of the two varieties of conifers was established. In general view, recommendations are made for changes to the current norms for the construction of solid timber structures. Keywords: : physic-mechanical properties, bulk weight, wood defects, temporary resistance.

Surface burning effectiveness of five commercial wood species in makassar againts Schizophyllum commune Fr.

Wood as a natural material is known to be susceptible to various biodeterioration agents. This research aims to determine the effectiveness of wood surface burning on the physical changes of wood and the attack of Schizophyllum commune Fr. The research was conducted in several steps, starting with the collection of wood samples from a Timber TradingUnit (UD) in Makassar City. The samples were prepared with dimension of 5 x 2,5 x 1,5 cm3, and each side of the samples was evenly burned using a torch for two to five minutes, resulting in a uniform thickness of 1-2 mm for the burned surface. Five types of wood were used for the surface burning, namely white teak (Gmelina arborea), sengon (Albizia chinensis), bayam (Intsia bijuga), teak (Tectona grandis) and meranti (Shorea spp). The research consisted of two treatments, one without burning and the other with burning. The results showed that the moisture content of all five wood species decreased after the burning process, with moisture content reductions of 15,61% for G. arborea, 14,30% for A. chinensis, 14,33% for I. bijuga, 11,37% for T. grandis, and 20,43% for Shorea spp. Regarding the aspect of fungal attack, the burning process did not inhibit fungal spread from the sides to the middle of the wood surface, but the burning treatment contributed to a lower weight reduction in the test samples compared to the untreated ones.

Numerical analysis of wood beam bending with verification of breaking force

The work represents the continuation of the research of the maximum bending stress force of a wooden beam up to the moment of failure, which is defined experimentally and with a corresponding mathematical model. The goal was to confirm the accuracy of the mathematical model of the breaking force using numerical simulation and the Solid Works software. Five different types of wood and five different beam thicknesses were used as input parameters whose influence was monitored trough the simulation. The stress deformation state and deflection for the calculated fracture forces were analysed separately for each variant. The breaking force model, which is defined depending on the density of the wood and the thickness of the board, proved to be adequate for defining the maximum stresses and deflections when bending beams.

Optimization of solid wood workability parameters in the planing process

It is known from theory and practice that the workability of wood depends on structural parameters that are closely related to the physical, mechanical and chemical properties of the type of wood itself, and disturbance parameters that refer to the technological and geometric parameters determined by the specific processing regime. That machinability, in addition to the mechanical output sizes, is often expressed by the quality, that is, the roughness of the processed surface. By defining a mathematical model in the process of planing solid wood in which the input sizes are processing parameters: wood density (ρ), feed rate (m/min) and number of cutting spirals (z), and the spilled sizes are praamters of roughness of the treated surface (Ra and Rz), and by applying optimization methods, optimal solutions for the process of planing solid wood on planer machines will be determined, so that the obtained Yoptim model will aim to improve the workability of solid wood, specifically its roughness of the processed surface.

Accelerating Xinomavro Red Wine Flavor Aging Using a Pulsed Electric Field and Various Wood Chips

Pulsed electric field (PEF) treatment has gained significant attention within the food industry. This study examines the application of PEF combined with wood chips of diverse species to expedite the flavor aging process of Xinomavro red wine. Various wood chip species, including black locust, common juniper, apricot, sweet chestnut, cherry, apple, peach, and European oak, sourced from pruning residues were immersed in the wine prior to subjecting it to PEF treatment. The samples underwent a range of pulse durations and intervals during treatment. Comparative preparations encompassing wine without chips and wine infused with each wood type left at ambient temperature for 5 days were also examined. The sensory attributes and the volatile compounds (VC) were assessed through the utilization of headspace solid-phase microextraction and GC-MS. In the control sample, 12 VCs were identified, whereas in the samples, 22 distinct VCs were identified. Favorable sensory attributes across all PEF conditions were associated with the incorporation of cherry wood chips. These findings highlight the potential of PEF treatment to enhance the quality parameters of the aging process in Xinomavro red wine, capitalizing on the synergistic interaction between PEF and various wood chip species. This innovative approach holds promise for augmenting crucial oenological parameters of red wine, strengthening the use of PEF as an efficient technique to enhance the overall quality.

Evaluation of Safer House Roof Frame Models Using Coconut Wood Material

The use of coconut wood is considered an environmentally friendly alternative because coconut wood comes from people's plantations without destroying forests. Another problem in the wooden house industry is knowing that the method of making roof frames is not yet a safe standard. The objectives of this research are: 1) Provide information about how to obtain conventional wood and coconut wood materials. 2) Explain how to select the quality and type of wood. 3) Explain that coconut wood can be used as a roof frame. 4) Explain the technical obstacles to roof trusses using coconut wood. 5) Explain the model for making a roof frame based on the basic requirements for a safer house. The method used in this research is descriptive qualitative through qualitative data analysis. The results of the roof frame model for the Woloan house do not meet the requirements for a house that is safer from earthquakes

Adaptive strategies to freeze-thaw cycles in branch hydraulics of tree species coexisting in a temperate forest

Freeze-thaw cycles (FTCs) limit the distribution and survival of temperate tree species. Tree species with different wood types coexist in temperate forests and are subjected to the same FTCs. It is essential to understand how these trees differentially cope with xylem hydraulic failure induced by FTCs in the field. The branch hydraulic traits and nonstructural carbohydrate concentration of six coexisting tree species in a temperate forest were measured from mid-winter to early spring when the FTCs occurred from January to April. The percentage loss of hydraulic conductivity (PLC) was lower, and the water potential inducing a 50% loss of hydraulic conductivity (P50) was more negative in tracheid trees than in ring- and diffuse-porous trees, suggesting tracheid trees with narrow tracheid diameters showed less vulnerable to embolism and provided a lower degree of hydraulic failure during FTCs (stronger resistance). Ring-porous trees always showed lower hydraulic conductivity and higher PLC and P50, and these traits did not change during FTCs, suggesting that they might lose the hydraulic functions in winter and abandon the last year xylem. The P50 in diffuse-porous increased after several FTCs (frost fatigue), but that in tracheid species continued to increase (or even decrease) until the end of FTCs (69 cycles), suggesting that tracheid trees were less sensitive to frost fatigue than diffuse-porous trees. Soluble sugar concentration in deciduous trees negatively correlated with PLC at the end of FTCs, indicating that the effect of soluble sugar on refilling embolism occurred in early spring. While the soluble sugar concentration of deciduous trees decreased, that of two evergreen tracheid trees gradually increased, possibly due to the winter photosynthesis of evergreen leaves. Our results suggest temperate trees adopt different strategies to cope with the same FTCs. These findings enrich the understanding of plant hydraulics and carbon physiology in winter and provide insights into the response of different species coexisting in temperate forests under climate change.

Applications of distributed activation energy model on the pyrolysis of green renewable wood

Recycling and reusing biomass is an effective strategy to enhancing bioenergy utilization and minimizing resource waste. This study aims to investigate the pyrolysis mechanisms and kinetic predictions of typical Cypress Wood (CW), Fir Wood (FW), Old Cypress Wood (OCW), and Old Fir Wood (OFW) samples, Distributed Activation Energy Models (DAEMs) were employed to fit the pyrolysis processes of the two types of wood before and after natural aging. For this purpose, three activation energy distributions, Gaussian, Logistic, and Weibull, were selected to investigate the optimal reaction function model. Each model was simultaneously fitted the extracted experimental α and dα/dT data at three heating rates. Important features and relationships of the models were discussed, and the best model was chosen. Additionally, the isoconversional method was used to validate the optimal model, and the sensitivity of the best parameters were estimated. The result shows that the Weibull distribution is more effective in predicting the trend of the conversion rate against the activation energy. In addition, the most obvious effects of the pre-exponential factor and activation energy on the pyrolysis process.