Comparação entre valores de ensaios experimentais e calculados da resistência ao embutimento da madeira de Pinus taeda L.

To design connections between timber parts with metal dowels (nails or bolts), two phenomena must be considered: bending of the metal dowel and the embedment strength in the wood. The Brazilian Standard ABNT NBR 7190:1997 proposes the methods used in the laboratory tests to determine the embedment strength with the metal dowell and, in the absence of testing, specifies relations to calculate the embedment strength from the compression strength. The aim of this research was to compare the embedment strength values obtained by experimental tests and calculated by the relationships established by the Brazilian Standard ABNT NBR 7190:1997. By the results of the hypothesis tests, it was possible to conclude that the estimate of the embedment strength parallel to the grain proposed by the Brazilian standard ABNT NBR 7190:1997, establishing equivalence with the strength compression results in the same direction, must be effective to the wood species Pinus taeda L., however, the same was not found in the perpendicular direction with respect to the grain, possibly explained by the alpha(e) values in the equation to calculed fe(90)

Qualidade da madeira e da celulose de clones de Eucalyptus spp. de diferentes densidades

Pós-graduação em Ciência Florestal - FCA

Deterioração da madeira de Eucalyptus spp. por fungos xilófagos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Classificação de tábuas de madeira usando processamento de imagens digitais e aprendizado de máquina

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Avaliação econômica de diferentes composições veiculares empregadas no transporte rodoviário de madeira: estudo de caso

Transport is one the essential services for the development of most economic activities. In the forestry sector, the main transport used to carry wood from the forest to local consumption is road. The transport increases the producing costs of wood and may be responsible of a high percentage in the final price of the wood sold in the industry. To reduce the company’s costs and increase the efficiency of forest production those transport activities must be analyzed and improved. In that context, an economic analysis is the main objective of this work, evaluating three different types of log transport from a sawmill in São Paulo´s Southwest region. For this, a data collection was done to compound the costs and the incomes of timber transport, and that way, to do the economic analyses of each transport. The monitoring activities were done in the second 2013 half-year and the research achieved economic viability results utilizing tools and methods of Economic Engineering

Análise do comportamento térmico de paredes de madeira

This study consists in the observation and evaluation of the thermal behavior and distribution of wood composite walls, MDF – Medium Density Fiberboard, HDF – High Density Fiberboard, OSB – Oriented Strand Board and EGP – Edge Glued Panel. This study had the objective to present the experimental thermal behavior and to verify which one fit the thermal comfort standards for human labor For this work, was developed a thermal chamber, with one interchangeable side, so the wall prototypes would fit for each experiment. We studied walls made of MDF, HDF, OSB and EGP, which one had its own distinct behavior due to the panel construction. The EGP wall had shown the most reliable material for this usage at high temperatures. With this work, it was demonstrated the importance of choice for the right material and construction method for wooden composite walls, because if they were scaled poorly, the people exposed to them would be uncomfortable by the proportionate environment, and the costs for a resizing would be too high

Aproveitamento de resíduos de laminação da madeira para a produção de painel estrutural

Products derived from wood or engineered products are becoming interesting alternatives to the replacement of solid wood in various applications, from structural components to the furniture industry and packaging. Among these products, there are panels built by strands, particles and fibers, each one having their particular characteristics and potential of use. Since the different types of panels are produced, waste generation is part of the process, and that more technological it is, it still generates losses of raw materials. Based on the need for rational use of raw materials and using almost full of industrially processed wood, It arises the proposal of this work, which seeks to use waste from the lamination, like pieces of strands, broken strands, strands rough, cracked strands to produce panels with structural characteristics of the OSL panel (Oriented Strand Lumber), LSL (Laminated Strand Lumber) and OSB (Oriented Strand Lumber). Besides the use of waste, this paper seeks an alternative to the use of the adhesive, because the industry uses formaldehyde-based adhesives, which over the press, they emit large amounts of formaldehyde, which is very aggressive to humans and environment. The panels made with polyurethane resin based on castor oil and hot-pressed were characterized by physical and mechanical tests according to specifications of European Standard (EN). High values of tensile strength, elastic modulus and density were found in the results of tests. Adding to stable values of swelling and moisture content, the panel studied adds attractive features to the panel market, especially in the civil construction

Desenvolvimento de metodologia para a obtenção da cubicagem de madeira em toras empilhadas através de imagens digitais

Obtaining accurate estimates of the volume of stacked wood is important in view of the increasing value of wood as raw material. Therefore, the forest companies have become increasingly concerned about the methods currently used to convert cubic meters for stereo. In this context, emerged the need of optimizing the measurement process and accuracy of the volume of stacked wood. For this, companies have been testing methods with greater efficiency, speed and low operating cost. Existing methods made through approximate equations, and also by determining the conversion factor, called the stacking factor (Fe), are questioned, due to errors and inaccuracies. The use of digital photographs is an alternative method that would minimize operator intervention, allowing greater control and speed the process, thus eliminating part of the imprecision of the traditional method. The use of the method is viable, due to present an error of about 10% while traditional methods showed an error of 17%

Caracterização físico-mecânica de painel de MDP produzido com madeira de Eucalipto e Bracatinga

This work is the production of particleboard of particles reconstituted from MDP (Medium Density Particleboard) adding particles in the inner layer of Mimosa Scarelli, popularly known as bracatinga, the ratios of 0%, 25%, 50%, 75% and 100%. The panel produced is composed of three layers, two external particles with smaller particle size and an inner layer composed of particles of larger particle sizes. Assays were performed based on physical and mechanical NBR 14.810/2006 for the determination of the board density, thickness swelling, water absorption, moisture content, bending strength, shear strength and residual moisture, and testing of particle size not existing in the standard cited. The results were analyzed and compared the results of the commercial boards made from 100% eucalyptus, based on the limits specified by the ABNT NBR 14.810/2006. The values of the tests were close to the normative specifications indicating positively the production of MDP with wood decay.

Análise granulométrica do compósito cimentício produzido com adição de resíduos de madeira e escória

Since the early twenty-first century, the construction sector has been the second largest on the rise in the Brazilian industrial sector, with a growth of 1.4% in 2012, and is likely to remain at this level for a long time. However, unlike decades ago, the industry has been seeking in its manufacturing process, sustainable materials, encompassing in their works the concept of sustainability. Thus, the timber sector seeks to satisfy a market increasingly demanding, innovating techniques and utilization being less aggressive to the environment. The purpose of this study was to produce and evaluate the mechanical strength of the composite cement with the addition of wood residues and slag low oven. Therefore, it was made 42 specimen cement-slag-wood, carried out in two steps. Since at the first, it was varied only the slag particle size, and at the second, through the best result of the previous step, it was varied the wood particles granulometry. The mechanical performance of the composite was evaluated by the results obtained in the compression test and the physical test for determining the density of the material. In the first step of the process can be concluded that the best result was achieved with the use of slag particles retained on the 60 mesh sieve. In the second phase of the study concluded that the best results were achieved with wood particles with the large particles, i.e. particles retained on the 10 mesh sieve. Both in the first and in the second step it can be seen that there has been the influence of the particle size of the waste materials. With the obtained results, could be evaluated that the use of waste for the production of cement-slag-wood composite showed lower performance when compared to the results obtained in studies without the use of waste. However, some applications are feasible to be performed with the use of composite wood-cement-slag

Análise das propriedades da madeira de estrutura de telhado após a ocorrência de um incêndio

The present study evaluated the mechanical properties of pieces of wood coming from the roof structure of a residence subject fire in the rural area of Itapeva/SP. The structure was built 25 years ago using wooden beams of the species Guarucaia (Peltophorum vogelianum), where the specimens were removed. The research methodology included qualitative evaluation of the samples, estimating the layer pyrolysis and carbonization of the wood, measuring of density and mechanical tests of compression parallel to grain, tension parallel to grain and shear. The mechanical properties of wood were analytically correlated with the layers carbonization and pyrolysis that are influenced by the temperature and time of fire; these values were estimated at 1000 °C and two hours for the case in question. The results indicate that the strength properties of degraded wood are different from a healthy wood. The level of thermodegradation, in general, can be measured by density, result in weight loss due to decomposition of the wooden components.

Uma revisão sobre a resina uréia-formadeído (RUF) empregada na produção de painéis de madeira reconstituída

According to ABIPA (2009), Brazil is currently among the major producers of reconstituted wood panels, with one of the main factors for this condition, its climate and its large land area, which allows the cultivation of forests, which provide raw materials for these industries. To establish that market as power, Brazil has invested about R$ 1.3 billion in the last 10 years, yet designed an investment of 0.8 billion dollars over the next three years (BNDES, 2008). With the new investments in this segment, we expect a growth of about 66% in the resin consumption of urea-formaldehyde (GPC, 2009) which should also result in major investments by the companies producing this polymer. Currently employees are mainly three types of resins in the production industry panels, as follows: Urea-Formaldehyde Resin (R-UF), melamine-formaldehyde resin (R-MF) and Phenol-Formaldehyde Resin (R-FF). Especially the cost factor, the urea-formaldehyde resin is the most used by companies producing reconstituted wood panels. The UF-R is a polymer obtained by condensation of urea and formaldehyde reactors (usually batch type), characterized by being a thermosetting polymer which makes it very efficient for bonding wood composites. The urea-formaldehyde polymer, to present a quite complex, it becomes very difficult to predict the exact chain resulting in the process of condensation of urea with formaldehyde, so that a greater knowledge of its characteristics and methods for their characterization can result in greater control in industrial processes and subsequent decrease cost and improve the quality of reconstituted wood panels produced in Brazil

Obtenção de constantes elásticas da madeira de duas espécies de Pinus sp

There are many studies about longitudinal modulus of elasticity of wood, but you can´t say the same of transverse modulus, especially for conifers. The study aimed to characterize and compare the species Pinus elliottii var. elliottii and Pinus elliottii var. elliottii x Pinus cariabeae hondurensis (hybrid), and the longitudinal modulus of elasticity (E) and lateral (G) in bending, to analyze the modulus of elasticity in different spaces and to verify the species studied the ideal range is equal to 21 times the height of the specimen, as prescribed in the normative document NBR 7190/1997, as well as analyzing the relationship G = E/20 defined in the normative document NBR 7190/1997. The wood came from the farm located in Paranapanema, split at the mill São José and the rest of the work was conducted at the Experimental Itapeva Campus - UNESP. Were removed fourteen specimens of each species. The average values of the modulus of elasticity and cross were, respectively, 5828 MPa and 452 MPa for Pinus elliottii var. elliottii and 6407 MPa and 320 MPa for the species of Pinus elliottii var. elliottii x Pinus cariabeae hondurensis (hybrid). The trend lines for the plotted graphs showed an exponential behavior to near linear 21he will equal the constant after this value. We have found the relationship G = E/13, for Pinus elliottii var. elliottii and G = E/20 for hybrid. The results of the modulus and strength for Pinus elliottii var. elliottii and the hybrid were lower than those reported in the literature, showing that this batch inferior quality to apply to structures

Efeitos da variação do teor de umidade da madeira no processo de lixamento

The process of sanding wood is little known and industries use it in a practical way without having studied their best conditions before. There are few studies involving this type of machining. On this basis, this paper studied the effects of varying moisture content of the wood surface quality after the sanding process. It was used a sanding machine with flat horizontal cut parallel to the fibers, using: 02 different species (Pinus elliottii and Corymbia citriodora); 01 sanding abrasive (aluminum oxide) and 03 different particle size abrasives ( P80 , P100 and P120 ) . Initially, the pieces were acclimatized ( 2 ± 7% , 12% and 17% ± 2 ± 2 ) and subsequently passed by the sanding process, and therefore, the surface roughness was analyzed. For each condition, were performed 06 repetitions totaling 54 trials for each species. We analyzed the effects of wood moisture by capturing the power sanding, rougheness, acoustic emission and maximum temperature during the sanding process. The variation of moisture content produced changes in the surface quality of the finished parts, and these changes were more marked in Pinus than Corymbia. During the sanding process of the specimens with 7 % and 12 % humidity, there was a lower noise emission, power consumption and heating surface. When checking the roughness of these parts after this process, it was observed that the surface quality of them were superior in the parts sanded containing 17 % moisture

Ensaio de ligações de estruturas de madeira por chapas com dentes estampados em quatro espécies da família leguminosas

In the last years, the use of industrialized systems of lattice structures of wood as an alternative in the construction processes, is becoming more popular in Brazil, mainly for their commitment to the environment.The industrialized system of wooden lattice structures consists in a production of lattice structures, composed of pieces of wood where their mechanical connections are made with the sheet multi-toothed connectors (CDE).Among the many challenges to make this system competitive, the whole system of the connections between the pieces of wood not only must show functionality, but also speed, strength, versatility and economy. Referenced at Brazilian Standard for Wood Structures (NBR 7190/1997 - Project of timber structures) the sheet multi-toothed connectors, are analyzed using three test methods: tensile strength parallel to grain, tensile strength normal to the fibers and shear strength, all of them in two positions, αCH0=0o e αCH0=90o to four types of wood: Angelim (Vatairea heteroptera Ducke); Red-Angico (Parapiptadenia rigida (Benth) Brenae); Garapa (Apuleia leiocarpa (Vog.) Macbr) and Jatoba (Hymenaea stilbocarpa Hayne), belonging to the Leguminosae family and founded in several regions of Brazil.The purpose of this manuscript consists to analyze the mechanical connections with the sheet multi-toothed connectors through tests from NBR7190/1997