Raw Wood Research Articles

Decision-making model for the specification of wood as an input for the production of wooden musical instruments

Abstract The main aim of the paper is to propose formalised decision-making model for the selection of suitable parts of raw wood for the production of musical instruments and to decrease uncertainty in the purchasing process. It deals with the problem which was never solved before. The paper presents the methodology of input evaluation, considering the principles of sustainable development. We present by means of a supplier selection example and criteria evaluation, that an outranking approach may be very well suited as a decision-making tool for initial purchasing decisions. We have identified this step from the scientific point of view and from the questionnaire sent to musical instrument producers. There were used the following methods: questionnaire, decision tree and statistical methods of questionnaire processing. Our proposed decision tool/methodology could help on both sides of supply chain – as on the side of raw wood supply as on the side of raw wood demand. Based on the results of scientific research we can say that all assessed hypotheses were confirmed and, in the following, it was designed decision-making model by the method of decision tree. We have developed a conceptual model of buyer’s decision-making uncertainty can be reduced by the buyer’s perceptions of supplier trust, supplier commitment, and supplier dependence. Based on data collected from a questionnaire, our study confirms the negative effect of buyers’ trust in the supplier on their uncertainty in purchase decisions. It helps to optimise the identification, specification and evaluation of key factors for a wood as an input into the production of musical instruments. From the economic point of view, our proposals could help to increase value added in the production of wooden musical instruments and at the same time it could decrease possible waste from the undesirable raw wood input.

Kebijakan Hukum Rencana Induk Pembangunan Industri dalam Pemanfaatan Potensi Sumber Daya Industri Kehutanan di Indonesia

This article's objective is to review and discuss the legal guidelines of Indonesia's Master Plan for Industrial Development for the Use of Potential Forestry Industry Resources. The normative methods of legal research that were used to write this article. Forests are important natural resources that provide many ecological, economic and social benefits. Paper is just one of many products and services for which the forestry industry provides raw materials, wood, furniture and building materials. The industry is subject to various laws and regulations governing the management, harvesting and utilization of forest resources. This paper provides an overview of industrial law in the forestry industry, covering key laws and regulations, their impact on the industry, and the legal framework. Industry forest law refers to the legal framework governing the management and utilization of forests for industrial purposes. It includes regulations on logging, reforestation, forest conservation, and the protection of indigenous communities. The aim is to balance the economic benefits of industrial forestry with the need to ensure sustainable forest management and protect the environment.

Modification of Epoxy Compositions by the Application of Various Fillers of Natural Origin.

A series of composites based on epoxy resin filled with additives of natural origin were prepared to investigate the influence of such fillers on the properties of the epoxy compositions. For this purpose, the composites containing 5 and 10 wt.% of additive of natural origin were obtained using the dispersion of oak wood waste and peanut shells in bisphenol A epoxy resin cured with isophorone-diamine. The oak waste filler had been obtained during the assembly of the raw wooden floor. The performed studies include testing of samples prepared using unmodified and chemically modified additives. Chemical modification via mercerization and silanization was performed to increase the poor compatibility between the highly hydrophilic fillers of natural origin and the hydrophobic polymer matrix. Additionally, the introduction of NH2 groups to the structure of modified filler via 3-aminopropyltriethoxysilane, potentially takes a part in co-crosslinking with the epoxy resin. Fourier Transformed Infrared Spectroscopy (FT-IR), as well as Scanning Electron Microscopy (SEM), were carried out, to study the influence of performed chemical modification on the chemical structure and morphology of wood and peanut shell flour. SEM analyses showed significant changes in the morphology of compositions with chemically modified fillers, indicating improved adhesion of the resin to lignocellulosic waste particles. Moreover, a series of mechanical (hardness, tensile strength, flexural strength, compressive strength, and impact strength) tests were carried out, to assess the influence of the application of fillers of natural origin on the properties of epoxy compositions. All composites with lignocellulosic filler were characterized by higher compressive strength (64.2 MPa-5%U-OF, 66.4%-SilOF, 63.2-5%U-PSF, and 63.8-5%SilPSF, respectively), compared to the values recorded for the reference epoxy composition without lignocellulosic filler (59.0 MPa-REF). The highest compressive strength, among all tested samples, was recorded for the composite filled with 10 wt.% of unmodified oak flour (69.1 MPa-10%U-OF). Additionally, higher values of flexural and impact strength, concerning pure BPA-based epoxy resin, were recorded for the composites with oak filler (respectively, flexural strength: 73.8 MPa-5%U-OF and 71.5 MPa-REF; impact strength: 15.82 kJ/m2-5%U-OF, 9.15 kJ/m2-REF). Epoxy composites with such mechanical properties might be considered as broadly understood construction materials. Moreover, samples containing wood flour as a filler exhibit better mechanical properties compared to those with peanut shell flour (tensile strength for samples containing post-mercerization filler: 48.04 MPa and 40.54 MPa; while post-silanization 53.53 MPa and 42.74 MPa for compositions containing 5 wt.% of wood and peanut shell flour, respectively). At the same time, it was found that increasing the weight share of flour of natural origin in both cases resulted in the deterioration of mechanical properties.

Sustainable Architecture in Developing Countries: Harvest Map of the Lusaka Territory, Zambia

In Zambia, Western materials, techniques, and technologies, a symbol of emancipation, are replacing the local building culture, which is relegated to the poor sections of society, with a negative impact from an environmental, social, and economic point of view. Designing and building sustainable architecture in developing countries is a particularly complex task mainly because of the absence of scientifically codified information about vernacular architecture and available resources. The starting point for designing and building sustainable architecture is to know the territory and its resources. The research outlines the harvest map of sustainable resources in Lusaka’s geographic surroundings, created through site surveys and analysis of international databases. The method for creating a harvest map follows well-defined steps involving knowledge of climate, intangible resources, and material resources as described below. Knowledge of the climate is intended to enable a critical reading of the area’s resources; it is functional to understand the logic of traditional architecture and consequently to identify fields of innovation in it. Intangible resources are related to the building culture and techniques and technologies of vernacular architecture of the territory; material resources, on the other hand, are related to traditionally used materials, raw materials not yet exploited, but potentially usable and waste materials. The vernacular architecture of the Lusaka territory is based on low-tech systems and natural materials (mainly raw earth, plant fibers, wood, and bamboo). There are also tree species in the territory that, for their quantity and performance, could be used in the construction field, as well as waste materials from common use or from the agricultural supply chain. Starting from this harvest map, every designer has the knowledge of the area from which to use already known building systems related to the resources of the area or innovate them while respecting local culture and resources.

A Fast Instance Segmentation Technique for Log End Faces Based on Metric Learning

The diameter of the logs on a vehicle is a critical part of the logistics and transportation of logs. However, the manual size-checking method is inefficient and affects the efficiency of log transportation. The example segmentation methods can generate masks for each log end face, which helps automate the check gauge of logs and improve efficiency. The example segmentation model uses rectangle detection to identify each end face and then traverses the rectangular boxes for mask extraction. The traversal of rectangular boxes increases the time consumption of the model and lacks separate handling of the overlapping areas between rectangular boxes, which causes a decline in mask extraction accuracy. To address the above problems, we propose a fast instance segmentation method for further improving the efficiency and accuracy of log-checking diameter. The method uses a convolutional neural network to extract the mask image, rectangular frame prediction image, and embed the vector image from the input image. The mask image is used to extract the log end face region, and the rectangular frame prediction image generates an enveloping rectangular frame for each log, which in turn divides the log end face region into instances. For the overlapping regions of rectangular boxes, a metric learning paradigm is used to increase the embedding vector distance between pixels located in different logs and decrease the embedding vector distance between pixels of the same log, and finally the mask pixels of the overlapping regions of rectangular boxes are instantiated according to the pixel embedding vectors. This method avoids repeated calls to the contour extraction algorithm for each rectangular box and enables fine delineation of pixels in the overlapping rectangular box region. To verify the efficiency of the proposed algorithm, the log working pile is photographed in different scenes using a smartphone to obtain the end face recognition database and divide the training set, validation set, and test set according to 8:1:1. Secondly, the proposed model is used to obtain log end face masks, and the log end face ruler diameter is determined by an edge-fitting algorithm combined with a ruler. Finally, the practicality of the algorithm is evaluated by calculating the check-rule diameter error, running speed, and the error of wood volume calculation under different national standards. The proposed method has 91.2% and 50.2 FPS of mask extraction accuracy and running speed, respectively, which are faster and more accurate than the mainstream instance segmentation model. The relative error of the proposed method is −4.62% for the check-rule diameter and −4.25%, −5.02%, −6.32%, and −5.73% for the wood volume measurement under the Chinese, Russian, American, and Japanese raw wood volume calculation standards, respectively. Among them, the error of the calculated timber volume according to our standard is the smallest, which indicates that the model in this paper is more suitable for application in domestic log production operations.

Economic Efficiency of Pine Wood Processing in Furniture Production

The wood industry faces challenges due to rising prices and limited wood availability, putting pressure on material efficiency in wood processing. This justifies the analysis of the relationship between efficiency and economy in pine wood processing. The study aimed to measure the impact of variations in the thickness of logs, changes in the technology of their further processing, and changes in prices of raw materials and products on the material efficiency in the context of large-scale production of furniture elements made of pinewood. The raw material input consisted of three categories of log sizes, from which the specialized purpose lumber was produced. The lumber was then processed into semi-finished furniture elements with three technologies: without detecting natural wood defects, with human detection, and with automatic detection. The study was conducted in Poland from 2020 to 2022. The material efficiencies in every stage of the analyzed wood processing and the cost efficiencies were calculated and analyzed based on the results obtained under real industrial conditions. The main findings are as follows: (1) when comparing the logs in the three tested diameter ranges (14–23 cm, 23–30 cm, and more than 30 cm), it can be observed that the overall material efficiency of sawing is in the range of 70%–85% and increases with the thickness of the log; (2) the share of 38 mm specialized sawn timber in the total amount of sawn timber was 41%–58% and increased with increasing log diameter; (3) the economic efficiency of the technological process is 170%–290%, based on the log size and the technology of further processing employed. The determining factor affecting cost efficiencies is unexpected changes in raw material prices and product demand in 2022. The findings suggest that while improvements in processing technology can boost efficiency, they cannot fully offset the rise in raw wood material prices.

The Role Of Inter-Sectors In Agroforestry Development In The Community Forest Environment, Pacitan District

Communities around the forest need to be encouraged in the development of forestry plants by the community either independently or with the assistance—of the government so that environmental sustainability can be adequately controlled. The development system carried out by the community, in general, is a hybrid system or better known as the agroforestry system. This study aims to identify sectors related to efforts to develop forestry plants.airly well-established economic condition. Development of forestry plants with this system . However, few people also develop a monoculture system, especially those with large enough land and who do not depend on the ground. Building role synergy between sectors supporting the development of forestry plantations is urgently needed to increase the quantity and quality of raw materials to meet the needs of the timber industry, both locally and nationally. Three critical sectors that must synergize in supporting the development of forestry plantations by the community are research and educational institutions, the government, and the market (industry). These three sectors are expected to be able to build attractive incentives for the community so that the community continues to preserve timber plants. Research and educational institutions can provide information and technology related to efforts to increase forestry plant production. Both information and technology from social, economic, and silvicultural or cultivation aspects. Information and technology produced by these research and educational institutions can be used as input and consideration for the government in formulating programs and policies related to developing timber plantations on private land. Through the formulation of its policies and work programs, the government is expected to initiate, facilitate and assist the community in developing forestry plants. Furthermore, the market sector, especially the timber industry, must be encouraged to create a conducive post-harvest climate so that the community continues to be motivated to increase the production of raw wood materials.

Sustainable Valorization of Wood Residue for the Production of Biofuel Materials Via Continuous Flow Hydrothermal Liquefaction

When forests are extensively cleared for infrastructure and agricultural purposes, over half of the wood generated is regarded as waste. To minimize the negative consequences and successfully use renewable energy sources, further applications must be investigated. Biomass has the potential to be converted into biofuels using a process known as hydrothermal liquefaction (HTL). The conversion of wood residue under continuous flow, subcritical HTL, under both untreated and alkaline pretreated conditions was examined in this study. According to the results, pretreatment with 4% NaOH sped up recovery times compared to using raw wood and increased glucose production by 1.8 times (equivalent to 90 g/L) in comparison to using raw wood. Additionally, the fluid's pH was raised from 6.1 to 3.5 due to the alkaline pretreatment, which also switched the hydrolysis of arabinose and cellobiose to rhamnose at 0.2 MPa. The average Net Energy Ratio (NER) for glucose during liquefaction reached values as high as 63%, while the energy output from glucose during the pretreatment reached 246 kJ. The move to green energy transition toward net zero will be aided by these findings, which will usher in new waste conversion techniques to produce sustainable biofuels using continuous flow HTL.Graphical Abstract

SMRT and Illumina sequencing provide insights into mechanisms of lignin and terpenoids biosynthesis in Pinus massoniana Lamb

Wood and oleoresin are important industrial raw materials with high economic value; however, their molecular formation and biosynthesis mechanisms in different tissues of Pinus massoniana remain unexplored. Therefore, we used single-molecule real-time sequencing technology (SMRT) and Illumina RNA sequencing to establish a transcriptome dataset and explore the expression pattern of genes related to secondary metabolites involved in wood formation and oleoresin biosynthesis in six different P. massoniana tissues. In total, 63.58 Gb of polymerase reads were obtained, including 41,407 isoforms with an average length of 1822 bp. We identified 3939 and 8785 isoforms and 161 and 481 transcription factors with tissue expression specificity and in the reproductive and vegetative organs, respectively. Eighty isoforms were annotated as cellulose synthases and 224 isoforms involved in lignin biosynthesis were enriched. Additionally, we identified 217 isoforms involved in the terpenoid biosynthesis pathway, with needles having the most tissue-specific genes for terpenoid biosynthesis. Some isoforms related to lignin biosynthesis were highly expressed in the xylem, according to the results of transcriptome sequencing and real-time quantitative reverse-transcription polymerase chain reaction. Our research confirmed the advantages of SMRT sequencing and provided valuable information for the transcriptional annotation of P. massoniana, which will be beneficial for producing better raw wood and oleoresin materials.

Valorization of hydrophobic wood waste in concrete mixtures: Investigating the micro and macro relations

This study investigates the effect of partially replacing fine aggregate with wood waste in concrete mixes in order to preserve natural resources (i.e., sand) and reduce the disposal of wood waste into landfill. A total of 81 specimens were prepared and divided into two groups based on their w/c ratio, namely: Group 1 with w/c = 0.46, and Group 2 with w/c = 0.42. Each group has two different percentages of replacement of fine aggregates (i.e., 5% and 7%). And each percentage was tested in two batches; namely raw wood waste and Silane-treated wood waste. The absorption, compressive strength, and tensile strength were measured for all the specimens. In addition, morphological and interfacial bonding analyses were implemented by running SEM and FTIR tests. The results show that replacing the fine aggregate with wood waste increases the absorption of the concrete mix up to 300% in certain mixes. The tensile strength was affected depending on the wood waste percentages. However, incorporating wood waste in concrete mixes reduced its compressive strength up to 65.5%. The Silane treatment of the wood waste improves the mechanical properties, as well as, the impermeability of the produced mix when compared with the raw wood waste specimens. The microstructural and interaction mechanism analyses revealed the formation of high content of ettringite and air voids in concrete with raw chippings, which negatively affect the mechanical properties of the mixture. It is recommended to avoid using raw wood waste in concrete mixes since it significantly harms its mechanical properties.

Modeling, Simulation, and Computer Control of a High-Frequency Wood Drying System

High-frequency wood drying is the modern method used in raw wood drying so that treated wood can be used further in various processes. Such systems are used because of the economy, energy efficiency, obtaining of good mechanical properties of the wood after treatment, as well as reducing time consumption. Therefore, it is extremely important to understand each component of such systems and processes. The mentioned systems are implemented using high-frequency generators based on vacuum tubes (VT). Their development and, in particular, optimization are by far more complex than the transistor systems; therefore, the development is now compelled to rely on computer modelling and simulation. In this research, a high-frequency (HF) generator of 20 kW output power and 1.5–15 MHz adjustable frequency based on VT was produced and then, with the corresponding model for VT itself and the rest of the developed circuit, was followed by computer simulation and real-system measurement. The model parameters were adjusted, which provided additional system optimization. An extra match of the results from the simulation and measurement was obtained; thus, the optimization was performed faster and more precisely. In addition, an easier and quicker way of adjusting parameters of the PID controller using a developed software-based control system was attained. The problems of cooling the VT anode under high DC voltage, as well as temperature measurement in the HF electric field, have been solved.

Advanced smokeless stove towards green environment and for sustainable development of rural women

Maximum family members in India are using traditional stoves to prepare their three meals per day. Generally, raw wood, cow dung and rice husk are the main fuels for running traditional stoves. Due to improper design of conventional stoves, incomplete combustion of fuel occurs which creates air pollution. The World Health Organization (WHO) estimates that about 4 million people die prematurely each year from diseases caused by indoor air pollution caused by inefficient eating practices. The survey also found that 60% to 70% of rural women are suffering from throat cancer and most of them are respiratory system problem. Accordingly, the AYUSH Department of the Government of India found that most of the deaths during the Corona period were due to failure of the respiratory system. To solve the problem of air pollution from traditional home stoves. We have developed a smokeless stove that uses wood as primary fuel and superheated steam as secondary fuel. Due to supply of hot steam, the built-in stove is used for household and community purposes. The main objective of this work is to establish complete combustion of fuel, provide a smoke free environment and thereby reduce health hazards in rural households, especially among women.

Wood raw materials and wood waste use for the building materials production (on the example of the Republic of Karelia timber industry)

The research is devoted to material resources analysis of the Republic of Karelia timber industry for the production of construction materials and to the optimal directions search for wood waste and illiquid wood use. The requirements for raw materials are analysed and inconsistencies in the classification of wood waste resources are revealed. Various methods of wood processing are considered and characteristic features and limitations on the applicability of raw materials in terms of size, quality, and breed characteristics are revealed. The conclusion is made about the main sphere of use of wood waste and illiquid wood, which is construction – civil, industrial, agricultural and architectural and aesthetic. The main directions of research are formulated to find ways to dispose of wood waste allowing for more complete use of their specific properties.

The effect of size and delignification on the mechanical properties of polylactic acid (PLA) biocomposites reinforced with wood fibres via extrusion

Raw short wood fibres generally showed better mechanical performance than long ones. Alkaline treatment did not improve the mechanical properties of the composites after reactive extrusion and injection moulding.

EFFEITO DO pH SOBRE A ATIVIDADE ANTIBACTERIANA E ANTIFÚNGICA DO EXTRATO PIROLENHOSO DE EUCALIPTO

ABSTRACT The study aimed to assess the effect of progressive neutralization on the antimicrobial properties against bacteria and yeasts of wood vinegar obtained from the pyrolysis of Eucalyptus urograndis (clone I144) wood. Wood samples were carbonized at a heating rate of 0.9 °C min-1 until a final temperature of 450 °C, totalizing 8 hours of carbonization. The raw pyrolysis liquids were left to settle, and the aqueous fraction was separated. Then, the aqueous fraction (raw wood vinegar - WV) was purified to yield the WV. WV samples were collected and neutralized from pH 2.5 until 7.5 (2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, and 7.5, by adding NaOH solution. Through the broth microdilution method, the antimicrobial effect of the neutralized samples at each pH was assessed on Pseudomonas aeruginosa (ATCC 27853), Salmonella enteritidis (ATCC 13076), Staphylococcus aureus (ATCC 25923), Streptococcus agalactiae (CEPA CLINICA), and Candida albicans (ATCC 10231). The minimum inhibitory concentration (MIC) and minimum bactericidal (and fungicidal) concentrations were determined through in vitro technics. Results were subjected to logarithmic regression analysis, and statistical models were fitted for each microorganism in the assessed pH range; as pH increased, a progressive decrease in the CIM increased, demanding higher concentrations of WV to inhibit microbial growth. The more resistant strains were S. aureus and S. agalactiae, which required an increase in WV concentration from a minimum of 6.25% at pH 2.5 to reaching 50% at pH 6.0. When at pH 7.0, both strains were not inhibited even at 50% (the highest concentration evaluated in the study). In contrast, C. albicans proved to be the most sensitive strain, starting from 3.12% EP at pH 2.5 and requiring only 25% for inhibition at pH 7.0. The behavior of P. aeruginosa and S. enteritidis followed the pattern of C. albicans, differing only at pH 7.0, where they required 50% of EP. As observed, even at neutral and slightly alkaline pH, the inhibitory activity of EP on microbial growth was maintained to some extent. Nevertheless, even when neutral and slightly alkaline pH values are reached, the inhibitory activity remains at a certain level. Higher pH values of the WV were associated with lower antimicrobial activity. However, its activity remained even at neutral and slightly alkaline pH values.

Electrostatic deposition of TiO2 nanoparticles on porous wood veneer for improved membrane filtration performance and antifouling properties

Wood has been a promising water purifier material on account of its abundant natural transport channels, easy processing, and renewability, which is mainly focused on its utilization in growth direction for effective separation.Wood veneer manufacured from raw wood block has a reversed-tree pore structure, and possesses advantages of low cost, easy fabrication, material saving, and abundant sources. To realize its functionalization and practicable application for membrane separation, modification of wood veneer is prerequisite. Herein, thin wood veneer with disparate utilization direction of wood was developed to design filter membrane loading TiO2 nanoparticles for treatment of dye wastewater. Wood veneer with reversed-tree transport pathways exhibits unique porous structure, and filtering direction and wood growth direction is almost orthogonal generated numerous sinuous channels. Thereout, sufficient area for loading TiO2 nanoparticles and contacting pollutants as well as appropriate water transport pathways at significantly shrinking thickness of wood (the thickness of 0.2 mm) can be provide by these sinuous channels. TiO2 nanoparticles was first modified by (3-Aminopropyl)triethoxysilane with high positive charge, and immobilized on negatively charged wood surface through atmospheric impregnation via strong electrostatic attractive interaction. Vast quantities of exposed TiO2 nanoparticles on wood cell lumens significantly enhance the adsorption ability for dye contaminants, resulting in a high membrane separation performance. The flux of TiO2/wood veneer membrane can achieve high level of 636.94 L/(m2h) with considerable methylene blue removal of 99.9% at 0.01 MPa. Meanwhile, it shows good cycling stability as well as decent flexibility and excellent mechanical strength. Moreover, the designed membrane with photocatalytic function of TiO2 also displays impressive decontaminated and recycling ability. The flux can recover its pre-recession level after 10 h light irradiation. The designed TiO2/wood veneer with simple preparation process and excellent water treatment capacity exhibits promising results for practical wastewater treatment.

ИЗУЧЕНИЕ ЗАВИСИМОСТИ ЭКСПЛУАТАЦИОННЫХ СВОЙСТВ ПЛИТНЫХ МАТЕРИАЛОВ НА ОСНОВЕ ДРЕВЕСИНЫ ЛИСТВЕННИЦЫ ОТ УСЛОВИЙ ПРЕССОВАНИЯ

The integrated use of raw wood materials in mechanical and chemical processing is a rather complex process: there are such wastes as bark, wood chips, lignocellulosic masses, and lignosulfonates. They can be disposed of with a positive economic effect. We consider the possibility of obtaining board materials directly from larch wood production waste using hydrothermal treatment without carcinogenic binders. The research examined the influence of pressing conditions, particularly pressure and temperature, on the properties of board materials and determined the optimal conditions for this process. We conducted a comparative analysis of the properties (strength and hydrophobic nature) of the obtained board materials with the industrial analogs.

Энергоемкость прессования древесного сырья при производстве биотоплива

Топливные брикеты из древесного сырья нашли широкое применение в хозяйстве, брикеты являются экологически чистым источником энергии. Технологический процесс их производства включает в себя несколько операций, основные из которых – транспорт, сушка, измельчение и непосредственно брикетирование (прессования) сырья. Современные исследователи изучают вопросы производства топливных брикетов не только из древесных опилок, но и из коры, ветвей, корневой. В этой связи возникает вопрос об оценке показателей эффективности производства биотоплива, включая энергоемкость. Наша статья посвящена развитию подхода к теоретической оценке затрат энергии на стадии прессования подготовленного древесного сырья. Исследование строится на анализе результатов, полученных ранее в области математического моделирования прессования упрочняющихся древесных материалов. В качестве основы использовано нелинейное уравнение прессования древесного материала, учитывающее увеличение предела пластичности материала брикета. Расчеты в статье выполнены с использованием методов приближенного решения дифференциальных уравнений в системе компьютерной математики Maple. Выполнена оценка энергоемкости и силовых параметров прессования хвойных древесных опилок. Результаты проведенных расчетов показали, что затраты энергии, вызванные прессованием материала брикета, практически линейно связаны с плотностью формируемого брикета. Для получения брикета из хвойных древесных опилок плотностью 1 т/м3 рабочий орган пресса совершает работу ориентировочно 40 кДж; для получения брикета 1,2 т/м3 – ориентировочно 55 кДж. По теоретической оценке, усилие рабочего органа в конце процесса прессования достигает 700 кН (70 тс). Fuel briquettes from wood raw materials are widely used in the economy, briquettes are an environmentally friendly source of energy. The technological process of their production includes several operations, the main of which are transport, drying, grinding and direct briquetting (pressing) of raw materials. Nowadays researchers are studying the production of fuel briquettes not only from sawdust, but also from tree bark, branches and roots. This raises the question of assessing the efficiency of wooden biofuel production, including energy consumption. Our article is devoted to the development of an approach to the theoretical assessment of energy costs at the stage of pressing prepared raw wood materials. The study bases on the analysis of the results obtained earlier in the field of mathematical modeling of the pressing of strengthening wooded materials. As a basis, a non-linear equation for pressing a wood material is used, taking into account the increase in the plasticity limit of the briquette material. The calculations in the article are performed using the methods of approximate solution of differential equations in the Maple computer mathematics system. The estimation of power consumption and power parameters of pressing coniferous wood sawdust is carried out. The results of the calculations showed that the energy costs caused by pressing the briquette material are almost linearly related to the density of the formed briquette. To obtain a briquette from softwood sawdust with a density of 1 t/m3, the working body of the press does work of approximately 40 kJ; to obtain a briquette of 1.2 t/m3 – approximately 55 kJ. According to a theoretical estimate, the force of the working body at the end of the pressing process reaches 700 kN (70 tf).

Investigation and modelling of the electrical charging effect in birch wood above the fibre saturation point (FSP)

Abstract Wood moisture content (MC) has a significant impact on all electrical properties of wood. Regarding the development of the (so-called polarization-type) wood moisture meter with the electrical charging effect for monitoring and controlling the wood drying process, it is of interest to expand the theoretical background of this type of novel wood moisture meter by means of modelling. Two mediums were selected for modelling – raw birch wood and, as a reference medium, birch liquid sap – into which two symmetrical carbon fibre measuring electrodes were inserted. In both mediums, direct current and alternating current were passed between electrodes at different electrode potentials. The electrical field and electrical response of the current-affected mediums were then measured and modelled in the time domain and frequency domain. The numerical results of modelling are comparable both in the time domain and frequency domain (i.e. if E = 1.8V, then Cs = 0.5 mF and C1,int = 0.7 mF). The concept of energetic chargeability (CHA(W)) of wood was defined and compared to conventional chargeability as defined by C. Schlumberger in 1913. Empirical dependencies of CHA(W) on electrode potential and primary energy W1 transmitted through the wood (sap) medium were found. In the frequency domain, frequency dependencies were found to distinguish between adsorption processes and mixed kinetics ranges in birch sap and in raw birch wood.

Management of Forest Residues as a Raw Material for the Production of Particleboards

Expanding the base of raw materials for use in the production of wood-based materials, researchers and panel manufacturers around the world are increasingly trying to produce panel prototypes from raw materials available in a given area and climate, or by managing waste from wood industry processing. The aim of the study was therefore to test the hypothesis that forest residues de-rived from Scots pine roundwood harvesting have the same suitability for the production of three-layer particleboard as the wood of the most valuable part of the Scots pine stem, by comparing selected properties of raw wood material and final product—particleboard. Characterization of both the raw material and the physical-mechanical and hygienic properties of the produced panels was carried out. For these panels from the tree trunk, MOR was 14.6 N/mm2, MOE 1960 N/mm2 and IB 0.46 N/mm2. The MOR and IB values turned out to be higher for the panel from the branch and are 16.5 and 0.72 N/mm2, respectively. Excessive swelling of the panels resulted in all manufactured particleboards meeting the standardized performance requirements of EN 312 for interior furnishing panels (including furniture) for use in dry conditions (type P2).