SAWING PATTERNS FOR THE BREAKDOWN OF Pinus caribaea var. caribaea WOOD ON PORTABLE SAWMILLS

The aim was to assess the effect of sawing patterns on lumber yield, energy consumption, and surface quality of Pinus caribaea var. caribaea wood sawn on a portable sawmill. The logs had an average diameter of 29 cm, length of 3 m, and age of 46 years. A specific sawing pattern was used for the production of cants and boards and another for two-sided cants, obtained after a subsequent edging operation. Log and board volumes were determined, and the ratio of these variables was used to calculate the lumber yield. The amount of energy used during breakdown was determined by measuring the electric current applied and time of execution of the process. Surface quality was assessed by the glass microsphere method, according to technical standards. Lumber yield ranged from 48 to 53%, considered satisfactory. Lumber yield and energy consumption were lower with the cant sawing pattern. Board surface quality was not influenced by sawing pattern, with all boards having fine to very fine surface textures. Energy consumption and board surface quality were not influenced by cutting position. Although the cant sawing pattern provided a lower lumber yield, the energy savings associated with the absence of edging operations may make it attractive for small lumber producers. However, this decision should be based on an economic analysis and take into account the market value of the wood to be processed

Durability of eucalypts wood in soil bed and field decay tests

This evaluated the natural resistance of wood from seven Eucalyptus trees in field decay and soil bed tests. Two 12-year-old trees were randomly sampled per species, with 2,2 m logs being obtained from the  basal section of each tree. The samples were taken in two positions in the radial direction of the stem (middle heartwood and transition zone; containing heartwood and sapwood). The field decay tests were installed in three municipalities in the southern state of Espírito Santo, and the soil utilized soil from the three field decay test areas. The field decay tests were evaluated after six, 12 and 18 months after installation and the soil bed tests after six months. The Scott-Knott test (p ≤ 0,05) was used in the analysis and evaluation of the tests. The sapwood-heartwood (transition region) exhibited the greatest mass losses for the field decay and soil bed tests. On average, for the soil bed test the lowest mass losses were observed for the soil of Vargem Alta (5,00 %), with greater mass losses observed for São José do Calçado (7,05 %) and Jerônimo Monteiro (9,90 %). In the field decay test the organisms present in the soil of São José do Calçado and related to the organic matter content Eucalyptus grandis and Eucalyptus saligna more intensely

Color variability and relationship with basic density and extractive content of Calycophyllum spruceanum wood

There are reports relating color to extractives, however there is a lack of information about the effect of other characteristics on the colorimetry of wood. Thus, this study aimed to evaluate the longitudinal and radial variability of color and its relationship with the basic density and extractive contents of Calycophyllum spruceanum wood from a six-year-old plantation located in Rio Branco, Acre, Brazil. The determination and assessment of the wood color were carried out by the Commission Internationale de L’Éclairage - CIE-L*a*b* system. The basic density and extractive contents were determined according to current technical standards. The species wood color was classified as yellowish olive. The highest and lowest lightness (L*) were longitudinally observed in the base (cutting height) and diameter at breast height (DBH), taken at 1.30 m from the ground. In relation to radial position, the lightness (L*) was lower in peripheral regions of the trunk. Higher concentrations of redness (a*) and yellowness (b*) and saturation (C) occurred along the DBH and the external radial position. In evaluating age, the extractive contents were not correlated to the wood color, while the basic density was correlated with a*, b*, C and h* colorimetric parameters. The colorimetric characterization of this specie contributes to its proper identification and a more homogeneous classification of lumber, and can be used from the log break-down (sawing) to its end use, adding commercial value to the wood

Operational performance of a small sawmill of the city of Alegre, Espírito Santo, Brazil.

AbstractSawmills are the most important wood industries in the Southern of the Espírito Santo State. The aim of this research was to analyze the operational performance of a small sawmill in Alegre, Espírito Santo state, Brazil, which process Eucalyptus sp. logs. The analysis was based on the study of lumber yield, operational efficiency and work delay ratio. The average lumber yield was 53.6% ranked as good for a small log hardwood sawmill, according to the literature. The average operational efficiency was 2.77 m³/worker/shift, and was ranked as low, even for small Brazilian sawmills, due to not classified logs, layout inadequacies, machinery bad conservation and low automation level. The average productive work was 69.6% and did not achieve the minimum rank of 75% suggested by the literature, because of the referred problems, and other ones. In general, for such sawmill the operational situation was considered poor, but it has potential to be improved. As serrarias são as principais indústrias madeireiras do sul do estado do Espírito Santo. O objetivo deste trabalho foi analisar o desempenho operacional de uma serraria de pequeno porte processadora da madeira de Eucalyptus sp. no município de Alegre, região sul do estado do Espírito Santo. Para tanto, a análise consistiu do estudo do rendimento em madeira serrada, eficiência operacional e amostragem do trabalho. O rendimento médio foi igual a 53,6% e foi considerado bom, para uma serraria que processa madeira de folhosas, quando comparado com dados da literatura. A eficiência operacional média foi igual a 2,77 m³/operário/dia, e foi considerada baixa, mesmo para serrarias brasileiras de pequeno porte, em consequência da falta de classificação da matéria-prima, inadequações de layout, mau estado de conservação do maquinário e baixo nível de automação. O trabalho produtivo médio foi de 69,6% e não atingiu o valor mínimo de 75% sugerido pela literatura, resultado dos problemas referidos, dentre outros fatores. De uma maneira geral, o desempenho operacional da serraria foi considerado ruim, de acordo com os índices avaliados, porém possui potencial para ser melhorado.AbstractOperational performance of a small sawmill of the city of Alegre, Espírito Santo, Brazil. Sawmills are the most important wood industries in the Southern of the Espírito Santo State. The aim of this research was to analyze the operational performance of a small sawmill in Alegre, Espírito Santo state, Brazil, which process Eucalyptus sp. logs. The analysis was based on the study of lumber yield, operational efficiency and work delay ratio. The average lumber yield was 53.6% ranked as good for a small log hardwood sawmill, according to the literature. The average operational efficiency was 2.77 m³/worker/shift, and was ranked as low, even for small Brazilian sawmills, due to not classified logs, layout inadequacies, machinery bad conservation and low automation level. The average productive work was 69.6% and did not achieve the minimum rank of 75% suggested by the literature, because of the referred problems, and other ones. In general, for such sawmill the operational situation was considered poor, but it has potential to be improved.Keywords: Log breakdown; lumber yield; operational efficiency; productive work

Physical and mechanical properties of juvenile schizolobium amazonicum wood

Growth in world demand for wood implies a search for new fast growing species with silvicultural potential, and in this scenario for native species such as Paricá . Thus, the objective of this study was determining the physical and mechanical wood properties of the Schizolobium amazonicum species (known as Paricá in Brazil). Trees were collected from commercial plantations located in the north of Brazil with ages of 5, 7, 9 and 11 years. Four logs from trees of each age in the longitudinal direction of the trees were obtained, and later a diametrical plank of each log was taken to manufacture the specimens which were used to evaluate some physical and mechanical properties of the wood. The basic density of Paricá was reduced in the basetop direction and no difference between the radial positions was observed, while the average basic density of this wood was characterized as low. The region close to the bark showed less longitudinal contraction and also greater homogeneity of this property along the trunk, while for tangential contraction the smallest variation was found in the region near the pith. Paricá wood contraction was characterized as low. Age influenced most of the mechanical properties, where logs from the base had the highest values of mechanical strength.O crescimento da demanda mundial por madeira implica na busca de novas espécies de rápido crescimento com potencial silvicultural e, nesse cenário, as espécies nativas como o paricá. Assim, o objetivo deste trabalho foi determinar as propriedades físicas e mecânicas da madeira da espécie Schizolobium amazonicum (paricá). As árvores foram coletadas em plantios comerciais localizados no norte do Brasil, com idades de 5, 7, 9 e 11 anos. Das árvores de cada idade foram obtidas quatro toras no sentido longitudinal das árvores e, posteriormente, um pranchão diametral de cada tora para fabricação dos corpos de prova, os quais foram utilizados para avaliar algumas propriedades físicas e mecânicas da madeira. A densidade básica do paricá reduziu no sentido base-topo e não houve diferença entre as posições radiais, em média, a densidade básica dessa madeira caracterizou-se como baixa. A região próxima da casca apresentou menor contração longitudinal, e também, maior homogeneidade dessa propriedade ao longo do tronco, enquanto para a contração tangencial a menor variação foi encontrada na região próxima à medula. A contração da madeira de paricá foi caracterizada como baixa. A idade influenciou a maioria das propriedades mecânicas, tendo a tora da base os maiores valores de resistência mecânica

Desempenho de uma serraria com base na eficiência e na amostragem do trabalho

O objetivo deste trabalho foi avaliar o desempenho de uma serraria de pequeno porte, localizada na região sul do Espírito Santo, processadora de madeira de eucalipto. O desempenho da serraria foi avaliado pela eficiência e pela amostragem do trabalho, por um período de quatro dias, cada um destes correspondente a nove horas de trabalho. A eficiência média foi de 5,06 m³/operário/dia, ao passo que o trabalho produtivo médio foi de 77,1%, superior ao valor mínimo de 75% sugerido pela literatura. A serraria apresentou um bom desempenho, conforme os parâmetros avaliados e a discussão de dados presentes na literatura específica, resguardadas as características intrínsecas da mesma, tais como porte, nível de automação, maquinário e matéria-prima

RADIAL GROWTH DYNAMICS OF Khaya ivorensis TREES FROM EXPERIMENTAL PLANTATION

ABSTRACT The objective of this study was to characterize the formation of growth rings in Khaya ivorensis wood, as well as to analyze the variation in the morphology of the vessel elements, aiming to understand the growth of this species in experimental plantations. Disks from the bases of five trees were collected, and after polishing the cross-section, demarcation of the growth rings limits was carried out. The anatomical study of the wood was conducted with the purpose of characterizing the rings, and their width was measured by means of scanned images of the disks. A historical series of data was obtained concerning the diameter of the trees to establish a correlation with the width of the rings measured over the years. The growth rings limits of African mahogany wood are demarcated by a thin layer of marginal parenchyma, and the presence of false rings has been observed. Significant annual growth correlation of 0.62 was observed among the trees, being the radial increment of irregular wood in the first years (wide and narrow rings), and highlighting the 3rd and 11th year of growth in which the largest increases were observed due to a biological adaptation tendency to the environment and the occurrence of thinning carried out in the planting area, respectively

Durability of eucalypts wood in soil bed and field decay tests

This evaluated the natural resistance of wood from seven Eucalyptus trees in field decay and soil bed tests. Two 12-year-old trees were randomly sampled per species, with 2,2 m logs being obtained from the basal section of each tree. The samples were taken in two positions in the radial direction of the stem (middle heartwood and transition zone; containing heartwood and sapwood). The field decay tests were installed in three municipalities in the southern state of Espírito Santo, and the soil utilized soil from the three field decay test areas. The field decay tests were evaluated after six, 12 and 18 months after installation and the soil bed tests after six months. The Scott-Knott test (p ≤ 0,05) was used in the analysis and evaluation of the tests. The sapwood-heartwood (transition region) exhibited the greatest mass losses for the field decay and soil bed tests. On average, for the soil bed test the lowest mass losses were observed for the soil of Vargem Alta (5,00 %), with greater mass losses observed for São José do Calçado (7,05 %) and Jerônimo Monteiro (9,90 %). In the field decay test the organisms present in the soil of São José do Calçado and related to the organic matter content Eucalyptus grandis and Eucalyptus saligna more intensel

Effect of planting spacing in production and permeability of heartwood and sapwood of Eucalyptus wood

The objective of this work was to evaluate the influence of different useful areas provided by the planting spacings (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) on the production and permeability of heartwood and sapwood of Eucalyptus grandis and Eucalyptus grandis × Eucalyptus urophylla clones at 4 years old. Regardless of the clone, there was no effect of planting spacing on the heartwood/sapwood relation and wood permeability. All clones showed a heartwood decrease with increased height, regardless of planting spacing, and E. grandis (B) was the only one that had its heartwood percentage positively and significantly correlated with the dendrometric variables (DBH and commercial height). The use of the dymethil yellow compound was indispensable in defining the heartwood and sapwood regions in the samples from 50% of the stem height. The heartwood permeability was low in all evaluated clones, suggesting vessel obstruction by tyloses or other deposits, while sapwood permeability reached 405.4 cm3/cm.atm.s.O objetivo deste trabalho foi avaliar a influência de diferentes áreas úteis proporcionadas pelos espaçamentos de plantio (3 × 1, 3 × 2, 3 × 3, 3 × 4 m) na produção e na permeabilidade do cerne e do alburno da madeira de clones de Eucalyptus grandis e Eucalyptus grandis × Eucalyptus urophylla, aos 4 anos de idade. Independente do clone, não houve efeito do espaçamento de plantio na relação cerne/alburno e na permeabilidade da madeira. Todos os clones apresentaram um decréscimo na quantidade de cerne com o aumento da altura do fuste, independentemente do espaçamento de plantio, e o E. grandis (B) foi o único que a percentagem de cerne correlacionou-se positiva e significativamente com as variáveis ​​dendrométricas (DAP e altura comercial). O uso do composto dymethil yellow foi indispensável na demarcação das regiões do cerne e do alburno nas amostras a partir de 50% da altura do fuste. A permeabilidade do cerne foi baixa em todos os clones avaliados, sugerindo obstrução dos vasos por tilas ou outras substâncias, enquanto a permeabilidade do alburno atingiu 405,4 cm3/cm.atm.s