Jorge Luis Monteiro de Matos

Pinus spp. na produção de painéis de partículas orientadas (OSB)

This work had the objective to study the species effects, and the wax addition in the OSB panels properties. The final conclusion was that the studied species are homogeneous among themselves and they produce similar quality panels. The produced panels attended to the minimum specifications of the CSA 0437.0 Canadian standard.

Influência dos atributos do solo sobre a qualidade da madeira de Pinus taeda para produção de celulose Kraft

To meet the increasing demand for forest products, much of the future timber supply will come from trees grown in managed plantations. This work was carried out to analyze the effects of soil attributes on Pinus taeda wood quality to produce Kraft cellulose at Klabin Parana Cellulose Co., in Telemaco Borba, PR, Brazil. The study focused on the influence of soil attributes on the anatomical, physical and chemical wood characteristics, as well as their relation to cellulose production. Eight sites with twelve-year-old trees were selected based on soil type, soil texture and primary vegetation. The soil variables studied were bulk density, total porosity, macroporosity, water availability, fertility and grain size distribution. For tree selection, dendrometric measurements of 50 trees were taken per site, and 5 average size trees selected per site. Total and commercial height and DBH were measured and discs removed. Tree samples were analyzed for basic density, chemical composition, tracheid morphological characteristics, nutritional status and Kraft cellulose production. The soil chemical attributes exerted significant influence on wood quality, but the soil physical attributes showed greater influence on cellulose productivity. Sites with higher growth rate and those with clay texture showed lower values of basic density, higher content of extract and lignin, thus showing lower content of holocellulose and cellulose, shorter and wider tracheids with thinner walls and higher lumen diameters, and lower cellulose yield. Based on these results, it was concluded that cellulose pulp characteristics can be estimated by analyzing wood characteristics combined with the existing site edaphic conditions.

Influência da idade e da posição ao longo do tronco na composição química da madeira de Eucalyptus grandis Hill ex. Maiden

The objective of this work was to study the chemical composition variation of the Eucalyptus grandis wood, of four different ages (10,14,20 and 25 years), from commercial stands. The samples were removed from three disks taken from the base and top of the first two 3 m logs, from sixteen trees (four per age), totalizing fourty-eight discs. The mean values of holocellulose, lignin and extractive contents were 69, 27 and 4%, respectively. The extractive and lignin contents increased with age, with greater concentrations near the base; the holocellulose content also decreased with age with greater concentrations in discs removed from the upper parts of the trunk.

Influência da idade e da posição radial na flexão estática da madeira de Eucalyptus grandis Hill ex. Maiden

The objective of this work was to study the static bending variation of Eucalyptus grandis wood along the radial plane at four different ages (10 _ 14 20 and 25 years), from commercial stands. The samples were removed from a diametrical board on each of sixteen trees (four from each age); taken from four equidistant positions (0, 33, 66 and 100%), in the pith-to-bark direction, with six replicates per position. It was found that the elasticity modulus (MOE) showed mean values of 129.230 kgf/cm2, and the rupture modulus (MOR) showed mean values of 854 kgf/cm2, both showing to be positively correlated with age and radial position in the pith-to-bark direction. The greatest values were obtained from twenty-year-old wood and located near the bark.

ESTIMATE OF THE DENSITY OF Eucalyptus grandis W. Hill ex Maiden USING NEAR INFRARED SPECTROSCOPY

This study aimed to analyze use of near infrared spectroscopy (NIRS) to estimate wood density of Eucalyptus grandis. For that, 66 27-year-old trees were logged and central planks were removed from each log. Test pieces 2.5 x 2.5 x 5.0 cm in size were removed from the base of each plank, in the pith-bark direction, and subjected to determination of bulk and basic density at 12% moisture (dry basis), followed by spectral readings in the radial, tangential and transverse directions using a Bruker Tensor 37 infrared spectrophotometer. The calibration to estimate wood density was developed based on the matrix of spectra obtained from the radial face, containing 216 samples. The partial least squares regression to estimate bulk wood density of Eucalyptus grandis provided a coefficient of determination of validation of 0.74 and a ratio performance deviation of 2.29. Statistics relating to the predictive models had adequate magnitudes for estimating wood density from unknown samples, indicating that the above technique has potential for use in replacement of conventional testing.

Produção de painéis aglomerados homogêneos e multicamadas de Melia azedarach (Cinamomo) e Pinus taeda com diferentes teores de resina

This research was developed to evaluate the quality of homogeneous and multilayer particleboards manufactured from Melia azedarach wood and Pinus taeda with different resin contents. The experimental boards were manufactured with the nominal density of 0,75 g/cm³, using the urea-formaldehyde resin in the proportion of 6% and 8% (solid content based on oven dried wood particles) in the internal layer and 8% and 10% in the external layers. The boards were pressed at the specific pressure of 40 kgf/cm², temperature of 160oC and press time of 8 minutes. The evaluations of the physical and mechanical properties of the boards showed the high potentiality of Melia azedarach for particleboard manufacture. The increase of resin content in the internal and external layers improved the properties of water absorption and thickness swelling. However, the mechanical properties were not affected.

Non-destructive estimation of pernambuco ( Caesalpinia echinata ) clear wood properties using near infrared spectroscopy

Caesalpinia echinata Lam. (pernambuco or pau-brasil), is recognised as the premier raw material for manufacturing bows for stringed instruments. Owing to limited wood supplies and concerns regarding species survival, interest exists in establishing pernambuco plantations to provide bow quality wood in the future. Rapid methods for estimating wood quality are also required and we examined the estimation of density, modulus of elasticity (MOE), and modulus of rupture (MOR) using near infrared (NIR) spectra collected from the transverse surface of blocks cut from the end of 73 pernambuco clear wood samples. The samples represented three populations: plantation grown pernambuco 25 years old (19 samples) and 30 years old (26 samples) and native forest pernambuco (28 samples). NIR spectra were collected using two spectrometers: a Foss NIRSystems 5000 and an Analytical Spectral Devices, Inc., AgriSpec (ASD) spectrometer fitted with a fibre-optic probe. For individual populations, density had the strongest statistics followed by MOE and MOR, with the native forest woods providing the best calibrations. The limited variation of the plantation woods explained their weaker statistics. Calibrations based on the three populations combined provided strong R2c for density (0.89 Foss spectra, 0.85 ASD spectral and moderate R2c for MOE (0.77 Foss spectra, 0.72 ASD spectra), while MOR calibrations were weak. The success of calibrations based on ASD spectra suggests that NIR assessment of pernambuco wood properties in the field may be possible.

Mozambique's charcoals: anatomy of nine native species

La mayor parte del carbon producido en el comercio en Mozambique es de bosques naturales, incluyendo las especies de alto valor comercial. Esta produccion afecta negativamente el medio ambiente y una de las principales razones es la falta de tecnicas de manejo forestal sostenible. Para facilitar el control del uso de los bosques, se caracterizan las propiedades de anatomia de carbon vegetal a base de Afzelia quanzensis, Amblygonocarpus andongensis, Combretum imberbe, Dalbergia melanoxylon, Guibourtia conjugata, Khaya nyasica, Millettia stuhlmannii, Pterocarpus angolensis y Swartzia madagascariensis. Todas estas especies tienen un alto valor comercial. Las muestras fueron carbonizadas a 450 °C durante 1 h. Algunas rupturas relacionadas con las perdidas estuvieron presentes en los carbones, pero la estructura mantuvo buena definicion de las caracteristicas anatomicas de las celulas y no influyeron en la distincion de las especies. La difusion de este conocimiento podria aliviar la presion sobre las especies valiosas y tambien puede ayudar con el control de la cadena de suministro de carbon

Evaluation of the use potential of nine species of genus Eucalyptus for production of veneers and plywood panels

The objective of this study was to evaluate the use potential of nine species of Eucalyptus for production of veneer sheets and multilaminated plywood panels. Veneers were cut using a pilot laminating lathe to a nominal thickness of 2.0 mm. Analysis included finding values of overall yield and yield according to three quality classes for the nine relevant species. Plywood panels were manufactured in a laboratory, consisting of five 2.0 mm veneer sheets which were bonded together with phenol-formaldehyde resin at a weight of 360 g/m² (double line). The panels were compressed using a specific pressure of 10 kgf/cm², a temperature of 140°C and a pressing time of 10 minutes. Results indicated that, with the exception of E. phaeotricha and E. pellita, all other Eucalyptus species had above 50% average veneer yield after lamination. Results of glue line shear testing and static bending parallel and perpendicular demonstrated that species Eucalyptus grandis, Eucalyptus saligna, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus viminalis, Eucalyptus robusta and Eucalyptus pellita have great potential within the parameters of this study for use in the production of veneer sheets and plywood panels intended for outdoor use.

Determinação do módulo de elasticidade em madeira laminada colada por meio de ensaio não destrutivo (''stress wave timer'')

RESUMO – As vigas estruturais de madeira sao formas racionais do emprego da madeira na construcao de estruturas, sendo obtidas pela associacao de pecas serradas e permitindo a utilizacao de tabuas com secoes e comprimentos variados, alem de combinacoes com madeira de qualidade diferenciada. Para atingir a resistencia maxima de uma viga de madeira laminada colada, pode-se utilizar a classificacao mecânica das pecas por meio dinâmico. O objetivo deste estudo foi estabelecer correlacao entre os metodos estatico e dinâmico de classificacao de vigas de madeira laminada. O trabalho foi desenvolvido com o emprego de pecas de madeira serrada de Pinus taeda e adesivo resorcina fenolformaldeido. O processo de fabricacao das vigas envolveu a classificacao das pecas, usinagem de emendas, formacao das lamelas, montagem e prensagem das vigas. Ja os ensaios envolveram a determinacao do modulo de elasticidade por meio do “stress wave method” e de uma maquina universal de ensaios. Os resultados foram analisados pela analise de regressao do estabelecimento da equacao de ajuste de correlacao. O sistema de classificacao visual utilizado na selecao de pecas foi insuficiente para se atingirem os valores maximos de modulo de elasticidade; o posicionamento correto das lamelas por meio do metodo dinâmico de classificacao teve como consequencia direta o aumento do modulo de elasticidade da viga, e houve baixa correlacao entre as formas de obtencao do modulo de elasticidade das vigas, nao sendo possivel a elaboracao de equacao adequada entre os metodos testados.