Estudo da viabilidade do uso da especie Eucalyptus dunnii (Maid) na manufaturade paineis de madeira cimento

The main objective of this dissertation is to assess the technical feasibility of the production of mineral boards, through the utilization of Eucalyptus dunnii flake particles of five (5) trees from a plantation located in The Municipal District of Colombo, State of Parana, as well as to value the particles treatments efficiency, the influence of the wood: cement ratio variation and the use of chemical additive. Used cement was commercialy available Portland type. Three particles treatments were analized: (1) particles without treatment; (2) particles treated with hot water for 1 hour at 80 °C; and (3) particles treated with NaOH 1% for 24 hours; with two wood:cement ratios (1:2.5 and 1:3.0) and two chemical additives (CaC12 and MgC12) effects over physical and mechanical properties of pannels. Chemical analysis of samples of all treatments were performed to verify their efficiency. Twelve treatments were generated from the interaction of above mentioned variables, in five panel repetitions which produced a total of sixty (60) paneis. The assessed physical and mechanical properties were: (1) static bending (ME and MR); (2) parailel compression; (3) internal bonding; and (4) dimensional stability (water absorption and thickness swelling after immersion in water). The results were statistically analyzed through factorial analysis of covariance. According to the results of chemical analysis the treatments did not attained their major objectives, which were to reduce the amount of wood extractives, Among the three analyzed factors, particles,. treatments caused a more pronounced effect on the panels properties, with negative contribution in the results. The increment of the wood:cement rate did not showed higher average values for the mechanical properties, except in intemal bonding. In general, MgCl2 was the chemical additive with better performance. The factors interactions showed different influence on the mechanical properties, but analogous influence on the dimensional properties. The combination between wood:cement ratio and chemical additive showed greater influence on MR (Rupture Modulus) and internal bonding . The combinations between particles treatments and chemical additive, particles treatments and wood:cement ratio, showed respectively major influence on ME (Elasticity Modulus) and paraliel compression. Particles treatments and wood:cement ratio interaction affected physical properties in greater degree

Eucalyptus spp. na produção de painéis de cimento-madeira

Este trabalho teve como objetivo a realização de estudos sobre as variáveis do processo de manufatura de painéis de cimento-madeira. Quatro tipos de cimento portland, quatro espécies de Eucalyptus, cinco granulometrias de partículas, cinco aditivos aceleradores de pega e três percentuais de aditivos, foram pesquisados. Análises foram realizadas com propósito de se averiguar o efeito dessas variáveis sobre a evolução da curva de hidratação do compósito cimento-madeira, a resistência à compressão de corpos de prova cilíndricos (CPC) e as propriedades físicas e mecânicas dos painéis. Além desses estudos, pesquisou-se também, o efeito da cura à vapor, sobre as propriedades mecânicas das chapas. As espécies E. peilíta, E. robusta, E. urophylla e E. citriodora foram coletadas de um reflorestamento localizado na Universidade Federal Rural do Rio de Janeiro no município de Seropédica-RJ. Para seleção do melhor tipo de cimento, da espécie mais compatível, da granulometria mais adequada, do aditivo e do seu percentual mais recomendado, a pesquisa desenvolveu-se em duas fases. lnicialmente, foi avaliada a influência de cada variável sobre a temperatura, o tempo de hidratação do compósito e a resistência à compressão axial de CPC. Índices de inibição da madeira, também foram determinados para classificar, quanto a compatibilidade, a espécie e a granulometria de partículas. Após avaliação desses estudos, procedeu- se a manufatura dos painéis cumprindo um delineamento experimental transcrito da fase inicial. Assim, o efeito produzido pelas variáveis investigadas no processo, foi, neste instante, observado nas propriedades físicas e mecânicas dos painéis. O principal propósito disto foi, além de selecionar as melhores variáveis, ratificar se as tendências dos resultados encontrados, em ambas as fases, se sobrepunham. O estudo sobre cura à vapor dos painéis, foi realizado com chapas produzidas já com as variáveis consideradas mais promissoras, em função dos resultados alcançados nas análises anteriores. Os painéis foram submetidos à três períodos de cura à vapor numa temperatura de 60 °C. Foi avaliada a resistência mecânica dos painéis para os períodos de maturação de 7, 14 e 28 dias, onde se identificou se tais períodos de exposição provocaram resistências equivalentes entre os três períodos de maturação explorados. Diante dos resultados alcançados pôde-se concluir que: o cimento portland ARI (Alta resistência inicial) é o mais adequado ao uso em chapas de cimento-madeira; a granulometria de partículas com tamanho intermediário foi a mais adequada ao uso porque, em praticamente todas as propriedades, apresentou resultados satisfatórios, além de contemplar a possibilidade do uso de granulometrias combinadas; o percentual de 4% do aditivo químico CaCl2, foi considerado o mais adequado e recomenda-se a sua utilização; com exceção da espécie E. citriodora, todas as outras três apresentaram boas possibilidades para uso em chapas de cimento-madeira; a variação do tempo de exposição dos painéis numa câmara de vapor, proporcionou efeitos satisfatórios nas propriedades mecânicas, principalmente, módulo de elasticidade, compressão paralela dos painéis, mas não apresentou efeito sobre o módulo de ruptura e ligação interna

Influence of geometry of the band-saw blades teeth in lumber quality and productivity

ResumoEste trabalho teve como objetivo avaliar o comportamento de dois modelos de dentes de lâmina de serra fita, durante o processamento mecânico de toras de Erisma uncinatum (cedrinho) e Dipteryx odorata (cumaru). A pesquisa levou em consideração aspectos qualitativos e quantitativos avaliados durante o desdobro de toras das duas espécies utilizando-se dois modelos de dentes de serra, modelo tradicional e modelo Senai. As variáveis que definiram a qualidade e a produtividade da madeira serrada, para ambos os modelos de dentes, foram, respectivamente, o desvio de corte e a velocidade de avanço do carro porta-tora. Os resultados mostraram que, para o modelo de dente denominado SENAI (MS), ganhos consideráveis em produtividade foram obtidos apenas para a espécie Erisma uncinatum. Essa vantagem não foi observada quando as toras processadas foram da espécie Dipteryx odorata, devido à consequente redução da velocidade de avanço. Em termos qualitativos, os ganhos obtidos com o modelo proposto foram observados para as duas espécies de madeira processada, com maior ênfase para madeira de cedrinho. Considerando esses resultados, o modelo Senai (MS) foi o mais recomendado para as condições de desdobro empregado, uma vez ter demonstrado ser o mais efetivo em termos de rendimento e, especialmente, qualidade de corte.Palavra-chave: Processamento mecânico de toras; ângulos de corte; velocidade de avanço. AbstractInfluence of geometry of the band-saw blades teeth in lumber quality and productivity. This research aimed to evaluate the behavior of two tooth models of band-saw blades, during log mechanical processing of Erisma uncinatum (cedrinho) and Dipteryx odorata (cumuru) using two types of sawtooth models: traditional model and Senai model. The research focused qualitative and quantitative aspects, evaluated during the sawing of the two species. The variables that define sawn wood quality and productivity, for both tooth models, were, respectively, the cut deviation, and the advancement velocity of log porter car. The results revealed that the “SENAI (MS)” tooth model has considerable productivity gains, only for de Erisma uncinatum specie. These advantages were not observed for the Dipteryx odorata species processed logs, due to consequent advancement velocity reduction. In qualitative terms, gains with the considered model could be observed for the two processed species, with emphasis for the medium density species. Considering the results, the Senai model (MS) was the most recommended for the applied sawing conditions, once the results demonstrated more qualitative effectiveness.Keywords: Mechanical processing of logs; cutting angles; feed rate.AbstractThis research aimed to evaluate the behavior of two tooth models of band-saw blades, during log mechanical processing of Erisma uncinatum (cedrinho) and Dipteryx odorata (cumuru) using two types of sawtooth models: traditional model and Senai model. The research focused qualitative and quantitative aspects, evaluated during the sawing of the two species. The variables that define sawn wood quality and productivity, for both tooth models, were, respectively, the cut deviation, and the advancement velocity of log porter car. The results revealed that the “SENAI (MS)” tooth model has considerable productivity gains, only for de Erisma uncinatum specie. These advantages were not observed for the Dipteryx odorata species processed logs, due to consequent advancement velocity reduction. In qualitative terms, gains with the considered model could be observed for the two processed species, with emphasis for the medium density species. Considering the results, the Senai model (MS) was the most recommended for the applied sawing conditions, once the results demonstrated more qualitative effectiveness.Keywords: Mechanical processing of logs; cutting angles; feed rate

STRUCTURAL DIVERSITY OF LOG OF Eucalyptus spp. GENOTYPES

Anatomical studies, besides being useful in the identification of the species, make it possible to generate information about the structure of the log in order to identify the relationships between the log and the technological properties of the wood. The aim of this work was to anatomically characterize the log of different genotypes of the genus Eucalyptus planted in the state of Minas Gerais – Brazil and to describe its main differences and/or similarities. Three genetically improved genotypes were evaluated, Eucalyptus urophylla x Eucalyptus grandis; Eucalyptus urophylla and Eucalyptus urophylla x Eucalyptus camaldulensis , aged whithin 6 to 7 years old. Discs of 9 trees were removed at breast height (1.30 meters from the ground). From each disk, specimens were obtained in the medulla-cambial direction with dimensions of approximately 2 cm³ to make permanent sheets, being that the anatomical characterization of the genotypes followed the recommendations of the IAWA Committee (1989). The results showed that the genotypes of Eucalyptus are very similar, however, differences were observed in the axial parenchyma and in the composition of rays

AGRUPAMENTO RADIAL DE TÁBUAS DE Eucalyptus grandis SUBMETIDAS AO PROCESSO DE SECAGEM CONVENCIONAL

O gênero Eucalyptus sp. apresenta defeitos naturais, de desdobro e secagem que acarretam perdas significativas de madeira. Por isso, conhecer a região de ocorrência dos defeitos pode ser uma ferramenta útil para quem beneficia madeira. Sendo assim, este trabalho objetivou agrupar radialmente tábuas de Eucalyptus grandis com base nos defeitos naturais e de secagem. Seis árvores foram desdobradas em tábuas e separadas em duas regiões: central (C) e externa (E). As tábuas centrais (C) apresentavam maior proporção de madeira da região próxima à medula; e as externas (E), maior proporção de madeira da região próxima à casca. Os defeitos ocorridos nas tábuas secas em estufa convencional, a 10 % de umidade foram avaliados por meio de análise multivariada e variaram no sentido medula-casca. A análise de agrupamento separou a madeira em duas regiões (central e externa) e a análise de componentes principais destacou quais defeitos foram dominantes para cada região. As tábuas externas (E) apresentram maior intensidade de encurvanento e encanoamento. As centrais (C) apresentaram maior intensidade de arqueamento, nós, bolsas de resina ou kino, colapso e rachaduras superficiais. Essas informações podem ser importantes para quem industrializa madeira, pois, sabendo em qual região o defeito mais ocorre, uma peça de madeira pode deixar de ser utilizada. No entanto, o fator operacional deve ser levado em consideração, pois características da madeira, o tipo e condições do equipamento de corte, método de desdobro, layout da serraria, pode inviabilizar a separação da tora em duas regiões.The Eucalyptus sp. genus presents natural debarking and drying defects that lead to significant wood losses. For this reason, knowing the region where the defects occur may be a useful tool for those who process wood. Thus, this work aimed to radially group Eucalyptus grandis boards based on natural and drying defects. Six trees were split into boards and separated into two regions: central (C) and external (E). The central boards (C) had a higher proportion of wood from the region near the pith; and the external boards (E) had a higher proportion of wood from the region near the bark. The defects occurring in the boards dried in conventional kiln at 10% humidity were evaluated using multivariate analysis and varied in the pith-to-bark direction. The Cluster analysis separated the wood into two regions (central and external) and the principal components analysis highlighted which defects were dominant for each region. The external boards (E) presented higher bow and cupped  intensity. The central boards (C) presented higher crook intensity, knots, gum or kino bags, collapse, and superficial cracks. This information may be important for those who industrialize wood, because by knowing in which region the defect most occurs, a piece of wood may no longer be used. However, the operational factor should be taken into account, because wood characteristics, the type and conditions of the cutting equipment, pitsawing method, and sawmill layout may make it unfeasible to separate the log into two regions

Color stability of weathered heat-treated teak wood

This study investigated the color stability in a heat treatment of teak wood (Tectona grandis) exposed to ultraviolet radiation under accelerated aging conditions. Nine trees from three different spacing levels were used. Samples of 150 mm x 75 mm x 20 mm were prepared and divided into two groups: heartwood and sapwood. Two levels of heat treatment (180 and 200°C) were used. The color was measured every 42 hours with a portable spectrophotometer using the CIE-Lab system. Accelerated aging was performed in a QUV/Spray chamber. The total cycle of exposure to ultraviolet radiation was of 168 hours at 340 nm. Tree planting spacing had no effect on color change after ultraviolet radiation. Untreated sapwood had greater color change than untreated heartwood. However, after heat treatment, sapwood showed high color stability, especially at a temperature of 180°C

Estudo da compatibilidade entre a madeira e as cascas de Eucalyptus grandis e cimento portland.

The characteristics of cement bonded particleboards can be jeopardized by chemical incompatibility between some lignocellulosic materials and cement, which can inhibit the glue of this cement; however, this effect can be minimized with chemicals treatments of the materials. The different species of Eucalyptus can be promising as raw material in the production of these panels, mainly residues produced in form of barks. The objective of the work was to evaluate chemical compatibility of wood and barks (without and with chemical treatment) of Eucalyptus grandis with cement. The chemical treatment of barks was carried out with sodium hydroxide. Results showed that the Eucalyptus grandis wood presented a moderate aptitude with cement, the treated barks presented high aptitude and the untreated bark presented extremely low aptitude. It was verified positive influence of the chemical treatment in the barks, making possible, in the future, the incorporation of these elements in the manufacturing of cement-bonded particleboard.As características dos painéis cimento-madeira podem ser prejudicadas em virtude da incompatibilidade química do cimento com alguns materiais lignocelulósicos que podem inibir a "pega" do cimento. Porém, este efeito pode ser minimizado com tratamentos químicos dos materiais. As diferentes espécies de Eucalyptus podem ser promissoras como matéria-prima na produção desse tipo de painel, principalmente os resíduos gerados na forma de cascas. O objetivo deste trabalho foi avaliar a compatibilidade química da madeira e cascas tratadas e não-tratadas quimicamente de Eucalyptus com o cimento Portland. O tratamento químico das cascas foi realizado com solução de hidróxido de sódio. Os resultados obtidos mostraram que a madeira de Eucalyptus grandis apresentou uma aptidão moderada ao cimento, as cascas tratadas, alta aptidão e as cascas não-tratadas, aptidão extremamente baixa. Verificou-se a influência positiva do tratamento químico nas cascas, possibilitando futuramente sua incorporação na manufatura de painéis cimento-madeira

AVALIAÇÃO DA SUPERFÍCIE DA MADEIRA DE Eucalyptus grandis Hill ex Maiden TRATADA TERMICAMENTE

http://dx.doi.org/10.5902/1980509817472The objective of this study was to study the machined surface quality of Eucalyptus grandis wood submitted to heat treatment. The machining operations realized on the boards obtained from the processing of six trees were: planing, thicknessing, tear in horizontal drilling, drilling, drilling hinge and sanding. 208 boards of 125 x 25 x 500 mm were selected, with 104 untreated and 104 heat-treated boards at maximum temperature of 190ºC. The evaluation of the surface was performed according to ASTM D-1666/87 standard. The result showed that the Eucalyptus grandis wood presents a good behavior during the machining tests, obtaining notes 1 and 2 (excellent and good), except for drilling hinge test in the bolt hole and drilling with 12, 8, 6 mm, reaching notes between 2 and 4 (good, regular and bad). The heat treatment reduced the number of defects on the machined samples, except for torn grain in some machining operations.http://dx.doi.org/10.5902/1980509817472O objetivo deste estudo foi estudar a qualidade da superfície usinada da madeira de Eucalyptus grandis, submetida ao processo de tratamento térmico. As operações de usinagens realizadas nas tábuas obtidas a partir do processamento de mecânico de seis árvores foram: desempeno, desengrosso, rasgo na furadeira horizontal, furação, furação para dobradiça e lixamento. Foram selecionadas 208 tábuas de 125 x 25 x 500 mm, sendo 104 não tratadas e 104 tratadas termicamente a uma temperatura final de 190ºC. A avaliação da superfície foi feita de acordo com a norma ASTM D-1666/87. O resultado mostrou que a madeira de Eucalyptus grandis apresenta um bom comportamento durante os testes de usinagem, obtendo notas 1 e 2 (excelente e bom), exceto para os testes de furação para a dobradiça no furo passante e furação com broca de 12, 8 e 6 mm, pois alcançaram notas entre 2 e 4 (bom, regular e ruim). O tratamento térmico diminuiu a quantidade de defeitos nas amostras usinadas, com exceção para o defeito grã arrancada, em algumas operações de usinagem

DENDROCHRONOLOGY OF TWO FOREST SPECIES IN THE URBAN AREA OF THE CITY OF PUERTO MALDONADO, PERU

We evaluated by dendrochronological methods the growth rings of these two species and their relationship with the climate. Wood samples were collected with the Pressler's probe. Measurements and analysis of the growth rings of the two species were performed using standard dendrochronology techniques. The master series (chronologies) were correlated with the climatic indices (precipitation and temperature), obtained from the NOAA meteorological database. The growth rings of the two species growing in the urban area are different and annual, delimited by the marginal parenchyma and semicircular porosity, in addition, C. alliodora presented fibrous areas. Both species presented an intercorrelation between the trees above 0.50. The maximum ages were 13 years for C. allidora and 32 years for C. fissilis. Likewise, the low correlation between the climate and the chronologies of the two species may suggest the influence of other ecological or anthropic factors that are intervening in the growth of these species. Finally, the potential of the two forest species for dendrochronological studies in the urban area of Puerto Maldonado Peru is demonstrated

EFFECT OF GENETIC MATERIAL AND FERTILIZATION ON ESTIMATING THE DRYING POTENTIAL OF Tectona grandis Linn F.

Drying is a fundamental step in the lumber production process. The definition of variables that affect the quality of the process, such as initial and final temperatures as well as drying potential, depends on the known technological knowledge of the wood, as well as on the experience of the drying process developed for a particular species. With this in mind, we developed an experiment using wood from four genetic materials (three clones and one seminal) of the species Tectona grandis cultivated with and without fertilization. This was done to estimate and evaluate the parameters used in the explanation of drying programs. The values of the initial and final temperatures, and those of the drying potentials, were estimated using the drastic drying methodology, which evaluates the drying rate and defect score (cracks and collapse). In addition to the drying parameters, the physical properties that affect the drying performance were also evaluated. The results show that origin and fertilization did not affect the initial and final temperatures. However, the potential drying parameters were significantly affected by the combination of treatments. Furthermore, the wood drying potential of certain genetic materials was positively affected by fertilization. Finally, the material from the fertilized areas had the lowest basic densities, the highest initial moisture content, and the highest drying rates