253 resultados para Umidade da madeira


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Nowadays, bamboo is being studied because of their strength properties according with their specific mass and speed of growth, which makes it an important alternative as a new resource that will help reduce pressure on forests and helpping them favoring the minimization of uncontrolled deforestation in many regions of Brazil. This study aimed, in general, to analyze physical and mechanical properties of the material with the divulgation of its potential for industrial application. To do so, in this research were determined in relation to the physical properties, moisture content, dimensional stability and the apparent densities and the mechanics and basic, just a tension parallel to grain, in order to observe the interference of various kinds of treatments (chemical, thermal and natural) on the strength and modulus of elasticity in this request. The species used was the Guadua angustifolia, a species native of Brazil. All tests were performed at Universidade Estadual Paulista - Campus Experimental Itapeva in the laboratory of Materials Properties. The methodology used for testing of moisture, density and tension parallel to grain were based on NBR 7190/1997 for the wood, and dimensional stability tests were based on much the same as in COPANT 462/1972 (South American) . The preservative treatments conducted followed the recommendation of each manufacturer. The values obtained in tests of physical properties were satisfactory especially with respect to density and dimensional stability analyzed by the coefficient of anisotropy, showed that, compared to wood, excellent quality for the shrinkage test, obtaining a coefficient of 1.2. With respect to parallel tensile tests to fibre results showed, in most cases, that test specimens with the presence of us have lower values of resistance and modulus of elasticity when compared with those without us. In the treatment of thermal-treatment there was an apparent treatment there was an apparent increase in...

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This work has in its outline the analysis of the mechanical properties of the composition of plastic residues, denominated “plastic wood”, aiming at establishing technical parameters for application of this material in substitution to the natural wood. Plastic-Wood is basically, a combination of several kind of plastic, previously selected, washed, dried and without metallic particles, which are agglomerated, extruded or introduced into a mold. The manufacturer can choose different formats and colors. During this monograph it can be observed the use of several kind of plastic, their mechanical properties and the plastic-wood production process. Also are presented features and applications of natural wood, in order to better compare their uses in several applications

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The objective of the present work was to evaluate Pinus’ glued laminated timber (glulam) beams and steel reinforced glulam beams, using PU mono-component adhesive in lamination step and epoxy adhesive to bond steel bars. The mechanical performance was verified through bending test, and the adopted method based on homogenized section, to considerate the differences between wood and steel mechanical properties. The homogenization section method proved itself effective in obtaining the stiffness of the parts in MLCA. The stiffness of reinforced beams increased 91% in comparison with glulam beams, differing only 5.5 % from value of stiffness calculated

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Classical statistical techniques which necessarily assume that all sampling units are random and independent were always used in the timber industry. Geostatistics considers that certain phenomena are characterized by spatial dependence: values of sampling units closer to each other tend to be more similar than values of sampling units farther away. This study aimed to characterize the spatial variability of the finishing (dyer) in the upper and lower surfaces of four edge glued panels by using geostatistical methods using geoR. Semivariograms were constructed for the analysis of spatial dependence. The spherical mathematical model was the best fit to the semivariograms generated, and was done the interpolation of the data (kriging) in samples where the distribution of dyer presents spatial dependence. In the bottom surfaces of two panels where the spatial dependence was detected geostatistical methods characterized a very large spatial variability due to the heterogeneous application of the finishing

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The need to reduce environmental damage and add value to waste causes more and more new alternatives appear to unite these two points. One of the main ways to achieve this in timber industries and the use of waste for making panels. This work was aimed at studying the influence of particle size and density in Eucalyptus mechanical compressive strength of cement composite wood. For this study was performed production and physico-mechanical characterization of specimens, using portland cement, water and waste eucalyptus. The methodology consists of a statistical study of the results obtained by calculating the density and axial compression tests and a subsequent comparison of these results with other studies. The results showed that there are significant differences in density and compressive strength when using different particle sizes the particles of eucalyptus. In general, the smaller the particle size, the lower the compression strength and the greater the density when the samples are produced with the same trait

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The study of physical and mechanical properties of wood is essential for its structural use and it is of great importance to the construction industry. Thus, this study aimed to determine the physical and mechanical properties of the wood Amaru - a hybrid of Eucalyptus, developed by Plantar Projects and Forest Products Ltda. In order to determine the properties of Amaru, round samples were used, which were provided to the Laboratory of Wood and Wooden Structures of the School of Engineering of São Carlos, University of São Paulo - LaMEM / EESC / USP. For the characterization of the physical properties, the apparent specific gravity and moisture content of the samples were determined. To the mechanical characterization, the following properties were evaluated: strength and stiffness in compression, strength and stiffness in bending, shear and tension. The procedures of the tests performed in this study were done according to the recommendations of the Brazilian Wood Standard ABNT NBR 7190:1997. The specimen used were confectioned in actual dimensions, according to as those used in the construction system proposed by Plantar. The results obtained from the tests performed showed that the mechanical properties approached the values proposed by the Wood Standard NBR 7190. The visual grading was important to provide a primary idea about the failure modes to be obtained from the tests performed. The bending test showed the modulus of elasticity (MOE) and Modulus of Rupture (MOR), which resulted in 15822 MPa and 101,7 MPa, respectively. The compression test resulted in values Ec0,m and fc0, 15698 MPa and 50,7 MPa. The tensile strength (ft0) of this hybrid was calculated and its value obtained was 60,8 MPa. The shear strength (fv0) was 8,2 MPa. The results obtained from the tests are the basis for engineers and architects to design structures using wood species Amaru

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This study aimed to evaluate the physico-mechanical performance of three PVA adhesive formulations according to the Brazilian standards for plywood testing and to evaluate the results with those presented in the technical literature and specified in normative documents. The study presents the production process of the panels, the obtaining of samples and, finally, the implementation of physico-mechanical characterization tests based on plywood Brazilian standards. For the panels production it was used a gramature of 120 g / m² and applied a pressure of 15 bars and two temperature combinations and pressing time for each adhesive. The commercial adhesives used were PVA 1810, PVA 1060 and Vinyltec 239. The physical tests conducted were thickness swelling, density, moisture content and water absorption. The mechanical tests were static flexion, for the determination of elasticity modulus (MOE) and rupture modulus (MOR), and shear in the glue line. Among the three formulations studied none showed good performance in the presence of water. However, other trials in the adhesive showed better results and closer to the commercially equivalent used, in the case the urea-formaldehyde, was the PVA 1810, that can be applied in non-structural uses and in environments without the presence of moisture

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The need to use waste from wood processing industry grows due to environmental demands imposed by laws, so like the need to introduce more competitive products in the market (it means better quality and acceptable cost) who must submit by the rational use of raw material, usually turning waste to sub products, what adds higher value for that. To this research, specific case from Ribon Company, located on Camaçari, Bahia-Brazil, has been studied. It is a treated wood producer. Bulk of monthly wood logs there is 70 m3. Its yield is 71,43%, where bulk of generated waste is monthly 20m3. As an exploitation way from generated waste, it has been suggested some options like: erosion protection to specific areas, a wildlife shelter as an henhouse etc, recreational articles, coal, linings, treadmills. However this research will give focus to the furniture design made of waste. As a conclusion, there is very much need to assign new utilizations to that sub used materials, since there is significant amount to increase company’s productive yield

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Charcoal is obtained from carbonization, much used in the steel industry for ore reduction, using as raw material the Eucalyptus. The present study aims to verify whether the main Eucalyptus saligna genetically modified produce quality charcoal with only 3.5 years old. The study was done with material collected from three trees, divided into five discs removed at 0, 25 , 50 , 75 and 100 % of the commercial height of the tree. The procedures adopted were based on standards published by ABNT. The results were satisfactory for the parameters: basic wood density with an average of 0.39 ± 0.0082 g / cm ³; volatile materials from coal with an average of 19.35 ± 3.27 %, fixed carbon content of the coal with an average of 75.62 ± 3.40 % and gross calorific value of coal with an average of 4694.43 cal / g, and unsatisfactory results for ash content averaging 5.03 ± 0.23 when compared to the values found in the literature. It was concluded that the studied wood is able to produce charcoal, but the factors of production should be better observed, such as heating time which exerted direct influence on the determination of ash content

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In the industries of wood processing (sawmills), where timber is sawn in equipment such as band saws, circular saws, trowel, thicknessers, among others, that mechanically transform this resource and use of electric motors, which are not unusually poorly scaled working or overloaded, often a factor that is not found in these industries and has fundamental importance in the production process is energy efficiency that is achieved by both technological innovation and through all the practices and policies that aim to lower energy consumption, lowering energy costs and increasing the amount of energy offered no change in generation. For both during the design of an electrical installation, both overall and in various sectors of the installation, investigations are necessary, considerations and uses of variables and factors that put into practice the theme of energy efficiency. Therefore, in this paper, these factors were calculated and analyzed for a wood processing industry (sawmill) in the municipality of Taquarivaí - SP, namely: active power, power factor, demand factor and load factor. Where they were small in relation to the literature, these events that occur when devices are connected at the same time and due to the conditions of processing the wood, where the engines have large variations in electricity consumption during the unfolding of the same, due to efforts with the load and idle moments between each machining operation in the equipment

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Bamboo has been studied because of its peculiar mechanical properties and numerous possibilities of use, besides being a fast-growing grass and short cutting cycle. This study aimed to analyze the mechanical characteristics of wood-bamboo composite material, where the samples were developed from the combination of layers of bamboo as a structural reinforcement in solid pieces of pine and EGP panel parts. The species of wood used was Pinus taeda, and the bamboo species Guadua angustifolia and Dendrocalamus giganteus. All work was conducted at the Universidade Estadual Paulista - UNESP in the laboratory of Physical and Mechanical Properties of Wood. Tests including the density and tension parallel to grain of the bamboo species used and the static bending of composites in order to use this in the furniture industry. For the tests have been used as a basis the requirements of the normative document NBR 7190/97. The values obtained in the tests showed a significant increase in strength and stiffness compared to unreinforced parts, where there was an increase in MOE and MOR in static bending in all specimens used in evidence. The results showed the possibility of reducing sections in furniture components and the possibility of improving the mechanical properties of parts with defects found in wood of Pinus Itapeva region of São Paulo

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As florestas tropicais são naturalmente amplos reservatórios de carbono devido à alta produtividade e extensão (Malhi et al. 2000). Em termos do ciclo do carbono, o papel das florestas tropicais como fonte ou sumidouro de CO2 tem sido amplamente debatido (Saleska et al. 2003), portanto, estudos sobre a capacidade de estoque de carbono destes ecossistemas são particularmente relevantes para compreendermos a dinâmica do CO2 para o atual ciclo global do carbono e para compreender o potencial desses ecossistemas atuarem como sumidouro ou fontes de CO2. O objetivo do presente estudo foi verificar se a biomassa de madeira morta acima do solo varia com a altitude (5-50m e 50-500m) em uma Floresta Ombrófila Densa (Mata Atlântica) para entender como o estoque de carbono dessa necromassa varia entre os locais, estoque esse que é matéria prima para liberação de CO2 para atmosfera pelo processo de decomposição. Para estimar a necromassa em pé foram consideradas todas as árvores mortas em pé com diâmetro na altura do peito (DAP = 1,3 metros de altura) maior que 4,8 cm (ou PAP > ou igual a 15 cm), de acordo com protocolo proposto pelo RAINFOR (Rede Amazônica de Inventários Florestais). Todas as árvores mortas em pé foram quantificadas e classificadas a partir da verificação do estado de decomposição da casca de cada indivíduo em quatro classes de decomposição, que possuem diferentes densidades de madeira relacionadas ao estágio de decomposição. A biomassa de madeira morta acima do solo variou com a altitude (figura 2). Essa variação foi de 1,14 Mg ha-1 (parcela B, Terras Baixas) a 7,57 Mg ha-1 (parcela J, F.O.D. Submontana). Em relação às fitofisionomias, houve uma variação de 8,40 Mg ha-1 (Terras Baixas) a 18,38 Mg ha-1 (F.O.D. Submontana)

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With the growing world energy demand mainly from developing countries like Brazil, Russia, India and China, the search for efficient sources of energy becomes a challenge for the coming years. Among the most widely used alternative sources, biomass is the one that grows in a more pronounced way. This study will assess the real possibility of having it as a heat source in an Organic Rankine Cycle, which employ heat transfer fluids as working fluids instead of water. From a regional data collection in agricultural production and their potential rice production and the resulting husk was defined as more appropriate. The availability of husks together with an amount of eucalyptus wood, provided by a company in the region on a monthly basis, were analyzed, and the low participation of the wood was discarded by the thermal contribution of little significance. Based on this, it was established the calorific value of fuel for thermodynamic calculations and the cycle to be used. It was then carried out the choice of working fluid from the literature and their availability in the library of software used for the simulations, the Engineering Equation Solver - ESS. The fluid most appropriate for the burning of biomass, Octamethyltrisiloxane (OMTS), was not included in the software and so the R227ea and R134a were selected. After the initial parameters modeling definition, as condensing temperature, efficiency and live steam conditions, the simulations were performed, and only the R227ea remained within the feasible thermodynamic and technological ranges. With this fluid the turbine power output was 265.7 [kW] for a scenario of 24 hours/day burning, 800.3 [kW] to biomass burning for 8 hours/day and 2134 [kW] for burning only 3 hours/day. The thermal efficiency of the cycle remained in the range of 6%, and for plants operating with the most... (Complete Abstract click eletronic access below)

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The steady increase in the price of oil and its derivatives, carbon credits, the concern with the environment combined with the precipitation of rain water and lack of water resources that Brazil has suffered in 2014 caused a migration of participation sources of energy in the Brazilian energy matrix. The hydropower sector suffered big drop at 2013 and is suffering so far, contributing thus to the generation and cogeneration of thermal energy using renewable energy sources such as: sugarcane bagasse, wood chips, rice husks, among others. The selling price of the electricity market reached the level of R$ 807, 00 MWh in January 2014 (Source: ANEEL), heating the Brazilian thermoelectric sector. Although thermoelectric use in bulk water as vaporizing fluid to produce electricity and use in various processes, water reuse plans have become an important factor in these industries. The increased use of biomass has been the bagasse which is allied to the sugarcane sector, strong market in Brazil, and consists basically use the rest of sugar cane, sugarcane industries that would play out. The sugar and ethanol industry is very unstable and only lasts for 6-8 months a year, and the remaining time in the period known as between crop that corresponds to the planting and harvesting of sugarcane and then enter the period of vintage which is the constant cane harvesting and crushing it. This instability of the market and the thermoelectric idle period leads the thermoelectric industries to seek other sources of renewable energy, such as wood chips (pine, Eucalyptus, Orange), rice husk, sorghum among others, to not be dependent on alcohol sector. The present work aims to study the use of wood chips as an alternative biomass for burning a fuel that essentially uses bagasse, the thermoelectric in question consists of two boilers that produce together 350 t / h ... (Complete Abstract click electronic access below)