Abstract: The aim of this study was to determine how varying the inputted surface area value of wood samples would affect the determination of kiln-drying schedules using the drastic drying test. For this purpose, eight individuals of two Eucalyptus clones were selected. Specimens were obtained for drastic drying tests at 100 °C, to measure the basic density and to determine the initial moisture content. The initial and final temperatures and the drying potential were calculated in 100 mm × 50 mm × 10 mm samples, considering the surface area to be 130 cm² (Updated Method), in contrast to the surface area of 100 cm² that is commonly used in the method known as the Standard Method. Based on these findings, kiln-drying schedules were set for the lumber from each clone. Although the significant differences aforementioned, it was observed that the drying schedules developed by Standard Method and Updated Method are similar.

Abstract: The quantitative evaluation of longitudinal drying strain can provide relevant information for the processing wood and lumber industry, especially with regard to reaction wood in Corymbia, since little has been published. The objective of this work was to evaluate the effect of the steam conditioning and the cooling on the longitudinal drying strain (LDS) obtained from a strain gauge, called extensometer, in boards of both normal and tension wood of Corymbia citriodora. Lumbers 30 mm thick were produced and kiln dried at the initial temperature of 40°C, final temperature of 65°C and drying potential of 2,1. The LDS were measured before and after steam conditioning on hot and cold lumbers. It was observed that the conditioning did not reduce the LDS. Hot lumbers showed higher LDS values than the cold lumbers. The LDS values measured in normal, tension and opposite woods were statistically similar, indicating that the type of wood was not an influential factor in the appearance of longitudinal drying stresses. Extensometer proved to be feasible for measuring LDS, allowing its easy and quick quantification.

Abstract Aim of this research was to evaluate the relationship between the biometrics of vessel-ray pits (RVP) and intervessel pits (IVP) with the water flow in different axes of Corymbia citriodora wood. C. citriodora wood specimens were used to correlate RVP and IVP dimensions with free water (FWFR), adsorbed (AWFR) and total (TWFR) flow. Correlations were made for three wood axes. Larger diameters of RVP facilitated FWFR, AWFR and TWFR in axial and tangential axis, however reduced permeability in radial direction of wood. Larger openings of IVPs reduced FWFR, AWFR and TWFR in axial axis of wood. Larger IVPs openings allowed higher FWFR and TWFR in wood radial and tangential directions, however, concomitantly reduced AWR. Effect of diameter of RVP and IVP on wood permeability should be evaluated for each axis. Thus, the opening of the C. citriodora wood pits can interfere in its permeability and consequently in its processing.

Abstract This research aimed to evaluate the relationship between Vessel-Ray Pits (VRP) and Intervessel Pits (IVP) and water flows in the different axes of Eucalyptus urophylla wood. Samples of E. urophylla wood were used to correlate the VRP and IVP dimensions with free, adsorbed and total water flow rates. Correlations were conducted for the three axes of the wood. Results indicated that overall, it could be observed that the greater VRP and IVP in the axial axis of wood increased free water and absorbed water flows. On the one hand, the greater VRP in the radial and tangential directions reduced the free water flow and increased the absorbed water flow. On the other hand, the greater IVP in the radial and tangential directions of the wood accelerated the free water outlet and reduced the absorbed water flow. The VRP and IVP of E. urophylla wood influenced water flow according to its physical state and wood axis.

ABSTRACT Many wood species have been employed as floorings, however their performance can vary greatly according to the wood properties and the type of application. Mechanical tests can be performed for simulating the wood floorings in service, but there are no standards for sorting the materials according to their quality as flooring. In this study, the tests carried out in commercial wood species to simulate the performance as flooring and propose a standard of classes resistance. Thus, the performance as wood flooring of Bowdichia nitida Benth (Spr.), Dipteryx odorata (aubl.) Willd, Mimosa scabrella Benth and Tabebuia impetiginosa in service were investigated. These commercial woods flooring were submitted to the falling ball, rolling load, floor surface indentation from small area loads and static and dynamic friction tests. The indentations caused were measured by micrometer coupled to a computer. According to the wood flooring performance in the simulation tests three resistance classes were established: high for indentations lower than 0.005 mm in floor surface indentation from small area loads, intermediate for depressions from 0.121 to 0.300 mm in rolling load test, and low for depressions higher than 0.301 in falling ball test. These classes can be used for predicting the performance, as wood flooring, of lesser known species.

ABSTRACT This study aimed to evaluate the behavior of samples of juvenile and mature Eucalyptus cloeziana wood when subjected to the drying process, and the influence of the anatomy on that behavior. In order to do this, saturated specimens from this woods measuring 10 × 5 × 1 cm were subjected to drastic drying at 100 °C, where the drying rates and the end check scores in different steps of the process were obtained. The fibers and vessels morphology, initial moisture and basic density were analyzed to help understanding the data obtained in the drying test. The juvenile wood presented 26% higher drying rate and 21% smaller drying time, also 53% higher end check score. Smaller fibers length and fibers wall thickness, higher vessels frequency and smaller vessels diameter were associated with higher total drying rate and water adsorption, as well as with the higher end check score.

Abstract: Aim of the study was to estimate the influence of the fiber length and basic density on microfibril angle of Eucalyptus microcorys wood. The study area was in an experimental planting at the Universidade Federal de Lavras, Minas Gerais State, Brazil. Three 37 year-old Eucalyptus microcorys trees were used, from whose stems six centimeter-thick discs were removed, cut at a high of three meters. The disks were sanded and planed to highlight the growth rings. Specimens were taken every 1,5 cm across the radius from pith to bark for determining microfibril angle, fiber length and wood basic density. The microfibril angles were determined by use of polarized light microscopy, while the fiber morphology and basic density were determined by usual methods. The averages found for microfibril angle (12,6°), fiber length (968 µm) and basic density (480 kg.m-3) are, in general, within the range of values reported for these characteristics of wood. The microfibril angle showed accentuated reduction of the average values in the pith-bark direction. The fiber length and basic density showed the opposite behavior. We observed that the density and fiber length may be used as a microfibril angle predictor, accounting for 96% and 79% of its variation, respectively.

ABSTRACT The objective of this study was to evaluate the flow of air and water in Eucalyptus grandis and Eucalyptus dunnii wood. Wood was collected from four trees aged 37 years in an experimental plantation of the Federal University of Lavras, Brazil. Planks were cut off the basal logs to produce specimens for air and water permeability testing. Results indicated that the longitudinal permeability to air and water of E. grandis wood were, on average, 5% and 10% higher, respectively, than that of E. dunnii wood. E. grandis and E. dunnii wood showed neither air nor water flow in the test for permeability transversal to the fibers, and longitudinal permeability to air exceeded that to water by approximately 50 fold in both species.

RESUMO A utilização da biomassa para produção de biocarvões já é uma realidade. Porém, pouco se sabe sobre a sua estrutura e composição, principalmente, mediante as transformações ocorridas durante o tratamento térmico. Estas informações são fundamentais, uma vez que terão impacto imediato na qualidade e aplicabilidade do material produzido. Portanto este trabalho objetivou analisar diferentes biomassas, caracterizando-as como potenciais para produção de biocarvões. Foram utilizadas madeiras de Eucalyptus urophylla e Corymbia citriodora e cascas de café. As biomassas foram moídas e peneiradas e, em seguida, armazenadas sob condições de temperatura e umidade controlada. Posteriormente realizou-se a caracterização dos materiais, por meio de análise química, química imediata, elementar (CHNS-O), térmica (TGA e DTA) e de espectroscopia vibracional na região do infravermelho (FTIR). De forma geral, todas as biomassas apresentaram potencial para serem utilizadas na produção de biocarvão, no entanto, a casca de café apresentou maiores teores de lignina, extrativos, cinzas e carbono fixo, o que, certamente, contribuiu para que a mesma apresentasse maior potencial de utilização como condicionador de solos. Com relação à análise de FTIR, observou-se a presença de bandas referentes aos grupos químicos recalcitrantes, como os carboxílicos e fenólicos nos espectros de todas as biomassas. O perfil dos termogramas de C. citriodora e de E. urophylla foram semelhantes entre si e diferentes da casca de café, que apresentou maior estabilidade térmica.

ABSTRACT The use of biomass for biochar production is already a reality. However, little is known about its structure and composition, mainly due to the changes occurred during the heat treatment. This information is crucial since it will have an immediate impact on the quality and applicability of the material produced. Therefore, this study aimed to analyze different biomasses, characterizing their potential for biochar production. Woods from Eucalyptus urophylla and Corymbia citriodora and coffee husk were assessed. The biomass was ground and sieved, and then stored under controlled conditions of temperature and humidity. Subsequently, the material characterizations were performed through proximate analysis, elemental analysis, thermogravimetric analysis and Fourier transform infrared spectroscopy (FTIR). In general, all biomasses presented potential to be used in the production of biochar, where low H/C and O/C ratios were found. The coffee husk has higher lignin, extractives, ash and fixed carbon contents, which certainly contributed to its greater thermal stability. The FTIR analysis showed the presence of bands related to recalcitrant chemical groups such as carboxylics and phenolics in the spectra of all biomasses. The thermogram profiles of the C. citriodora and E. urophylla wood were similar to each other, and different from that of the coffee husk, which showed higher thermal stability.

ABSTRACT High concentrations of airborne dust are observed during the cutting of medium density fiberboard (MDF) boards. This dust, at first considered just uncomfortable for workers, may be harmful to their health. The objective of this work was to evaluate the concentration of airborne dust during the cutting of medium density fiberboard (MDF). The experiment was developed in the MDF cutting sector of three furniture factories located in the city of Lavras/MG. The results showed that the mean concentrations of total dust suspended in these three furniture factories were above the tolerance limit set by the American Conference of Governmental Industrial Hygienists (ACGIH), giving evidence of a serious problem in these companies related to this type of risk agent.

RESUMO O objetivo deste trabalho foi determinar a densidade relativa aparente por meio da técnica de raios X da madeira e do carvão de um clone de Eucalyptus grandis x Eucalyptus urophylla com 6 anos. A amostragem consistiu na retirada de baguetas de 2 cm de diâmetro no DAP, com trado motorizado, em 50 árvores distribuídas em três classes de diâmetro. Após a determinação da densidade relativa aparente das baguetas, pela técnica de densitometria por raios X, as amostras foram carbonizadas em um forno elétrico (mufla) e suas densidades, determinadas pela mesma técnica. Os valores mais altos de densidade aparente da madeira utilizando a técnica de raios X foram encontrados nas classes diamétricas de 14,1 e 11,4 cm. Os valores de densidade relativa aparente nas amostras de carvão tenderam a aumentar no sentido medula-casca em todas as classes diamétricas.

ABSTRACT This research aimed to determine the apparent relative density by X-ray technique of wood and charcoal from a Eucalyptus grandis xurophylla hybrid clone with six years-old. The sampling consisted of the removal of 2 cm diameter (DBH) increment cores, with a motorized borer, in fifty trees distributed in three diameter classes. After the determination of the relative apparent density of the cores, by the x-ray densitometry technique, the samples were carbonized in an electric oven (muffle) and their densities determined by the same technique. The highest apparent density values of the wood using the x-ray technique was found for the diameter classes of 14.1 and 11.4 cm. The relative apparent density values in the samples of charcoal tended to increase in the pith-bark direction in all of the diameter classes.

Neste trabalho, objetivou-se avaliar o efeito da vaporização na taxa de secagem e na qualidade da secagem de tábuas de Eucalyptus grandis. Para isso, utilizou-se uma madeira proveniente de um plantio da Universidade Federal de Lavras, MG, Brasil, com idade de 24 anos. Árvores foram abatidas e suas toras foram desdobradas por um sistema de corte tangencial. Dividiu-se a carga de tábuas à metade, sendo uma delas para secagem com vaporização e outra sem vaporização. Na secagem com vaporização, após a fase de aquecimento, houve um tratamento de 3 horas a 90ºC e 100% de umidade relativa. A secagem ocorreu em estufa de secagem convencional e foram realizadas medições de defeitos e determinação da taxa de secagem. Os resultados indicaram que a vaporização foi eficiente, aumentando a taxa de secagem em 15% e reduzindo defeitos de secagem de 20 a 52%.

The objective of this work was to evaluate the effect of the steaming on the drying rate and drying quality of Eucalyptus grandis boards. For this purpose, wood from an experimental plantation of the Federal University of Lavras, Minas Gerais State, Brazil, with 24 years of age was used. Trees were felled and sectioned in logs and the logs were sawn by a tangential system. Half of the boards volume were steamed during 3 hours at 90ºC of temperature and 100% of relative humidity after the heating of the drying process. The other half was not steamed (control). The boards were dried in the dry-kiln and the resulting defects from the drying process and drying rate were determined. The results indicated that the steaming was effective in increase of the drying rate in 15% and decrease of the drying defects of 20 to 52%.

Objetivou-se, com este trabalho, estudar a permeabilidade ao ar e ao liquido no sentido longitudinal na madeira de Amapá (Brosimum parinarioides Ducke) oriunda da floresta amazônica. Além disso, identificar a influência das características anatômicas e químicas na permeabilidade dessa madeira. Foram coletadas no Estado do mPará - Brasil, três árvores de Amapá, das quais corpos-de-prova foram retirados e submetidos aos ensaios de permeabilidade, caracterização anatômica e análise química. A permeabilidade ao ar na madeira de Amapá foi de 63,7.10-9 m³.[m.(N.m-2).s]-1 e ao líquido de 2.07.10-9 m³.[m.(N.m-2).s]-1. Ocorreram baixas correlações entre a permeabilidade ao ar e ao líquido e as características anatômicas.

This paper aimed to study the permeability to air and liquid, in the longitudinal direction of "amapá" wood (Brosimum parinarioides Ducke), originating from the Amazon Forest. Furthermore, the influence of anatomical and chemical characteristics in the permeability of the wood was investigated. For this study, samples were collected from three trees, in the state of Pará, Brazil, and submitted to permeability test, anatomical characterization, and chemical analyses. The permeability to the air of the "amapá" wood was estimated at 63.7.10-9 m³.[m.(N.m-2).s]-1 and to the liquid was 2.07.10-9 m³.[m.(N.m-2).s]-1. There were low correlations between air and liquid permeability and the anatomical features.

A estocagem ao ar livre é o método mais utilizado de secagem de madeira para produção de carvão. Todavia, a secagem natural de toras é pouco estudada. O objetivo deste trabalho foi avaliar a interação entre estocagem e propriedades energéticas da madeira e do carvão. Toras de 1,2 m de comprimento, retiradas dos troncos a 1,3 m do solo, de dez diferentes materiais genéticos, foram utilizadas. As carbonizações ocorreram em mufla após um, dois e três meses de estocagem, à taxa de aquecimento de 1,67ºC/min, temperatura máxima de 450ºC e tempo de residência de 30 minutos. O poder calorífico da madeira, o rendimento gravimétrico na base seca e úmida, a análise química imediata e o poder calorífico do carvão foram avaliados. O poder calorífico líquido da madeira aumentou após a estocagem e, baseado neste parâmetro, o tempo ótimo de estocagem variou entre dois e três meses para os diferentes materiais. Considerando-se a carbonização, apenas o rendimento gravimétrico na base úmida foi afetado pela estocagem. A secagem foi importante para reduzir a umidade da madeira, favorecendo seu uso para energia.

The storage of logs in outdoors areas is the most commonly used wood drying method for charcoal production; however, studies on outdoor drying of logs are still scarce. This study aimed to evaluate the effect of storage time on the energetic properties of wood and charcoal. Logs of 1.2 meters in length extracted from trunks of 10 different clones at 1.3 m above ground level were used in this study. Carbonization in muffle furnace occurred after one, two and three months of storage at a heating rate of 1.67 ºC, maximum temperature of 450 ºC, and residence time of 30 minutes. Wood calorific value, gravimetric yields on dry and wet bases, chemical analysis, and charcoal calorific value were evaluated. The net calorific value of wood increased with storage time; the optimum storage time ranged between two and three months for different materials. Among the carbonization parameters, only the gravimetric yield on wet basis changed with storage time. Drying was important to reduce wood moisture, favoring its use for energy production.

O controle sobre os produtos obtidos no desdobro das toras é importante para a gestão da serraria e também para a redução dos impactos ao ambiente. O rendimento e o estudo de tempo são parâmetros para a avaliação do desdobro em uma serraria. No presente trabalho, objetivou-se avaliar o rendimento e o estudo dos tempos do desdobro de toras de Eucalyptus durante a produção de peças estruturais. Foram utilizadas dez toras de Eucalyptus grandis provenientes de um plantio com 15 anos de idade, retiradas de uma área da Universidade Federal de Lavras (UFLA). Na serraria experimental da UFLA, as toras foram serradas utilizando uma serra de fita e os pranchões foram resserrados em uma serra circular. As peças seguiram as dimensões estabelecidas na NBR 7190 (ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS - ABNT, 1997). As peças produzidas foram mensuradas e o rendimento calculado. Os tempos de todas as etapas do processo foram obtidos por meio de um cronometro e, em seguida, analisados os tempos efetivamente serrando e o tempo total de processamento das toras e pranchões. O rendimento médio do desdobro para a produção de peças principais foi de 20,9% e de peças secundárias foi de 22,9%. O rendimento médio do desdobro foi satisfatório, dentro dos valores obtidos em outros trabalhos. A serra circular quando comparada a serra de fita apresentou maior porcentagem de tempo efetivamente serrando a madeira. O tempo, efetivamente serrando, foi menos da metade do tempo total de processamento das toras.

The control over the products of the sawing of logs is important for the management of the sawmill and also to reduce environmental impacts. The yield and the time study are parameters for the assessment of unfolding in a sawmill. This study aimed to evaluate the yield and the time study of the sawing of Eucalyptus logs during the production of structural parts. This work used ten logs of Eucalyptus grandis from a plantation with 15 years of age, taken from an area of the Federal University of Lavras (UFLA). In the experimental sawmill of UFLA the logs were sawn using a band saw and the planks were resawn in a circular saw. The structural parts followed the dimensions laid down in the NBR 7190 (ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS - ABNT, 1997). The parts produced were measured and calculated yield. The times of all stages of the process were obtained using a stopwatch and then analyzed the time actually sawing and the processing time of logs and planks. The average of yield for the production of main parts was 20.9% and secondary part was 22.9%. Average yield of sawing was satisfactory if compared with the values obtained in other studies. The circular saw compared to band saw showed higher percentage of effective time sawing of wood. The effective time of sawing was less than half the total processing time of the logs.