RESUMO O objetivo deste estudo foi determinar a densidade básica da madeira e simular o comportamento em uso de pisos maciços produzidos com madeiras de cinco espécies tropicais: Dipteryx odorata (cumaru), Handroanthus spp. (ipê), Hymenaea courbaril (jatobá), Astronium lecointei (muiracatiara) e Bowdichia virgilioides (sucupira-preta). Nos testes de simulação foram realizados os ensaios de impacto da esfera de aço cadente, de atrito estático e dinâmico, de endentação causada por cargas aplicadas em pequenas áreas, de carga rolante e de abrasividade. Os resultados foram submetidos à análise de variância e ao teste de Tukey, a 5% de significância, e realizou-se a correlação de Pearson entre a densidade básica e os índices de cada ensaio de simulação de pisos. A densidade básica dos pisos de madeira das espécies avaliadas variou de 0,735 a 0,958 g·cm-3, sendo as madeiras de D. odorata, Handroanthus spp. e H. courbaril classificadas como pesadas e as de A. lecointei e B. virgilioides como moderadamente pesadas. Foi possível indicar os pisos de D. odorata, Handroanthus spp., H. courbaril e B. virgilioides para ambientes com tráfego intenso, onde há o arraste ou a queda de objetos, como indústrias e empresas. Já o piso de A. lecointei pode ser utilizado em ambientes residenciais, com tráfego leve, onde as cargas exercidas sejam baixas. Houve correlação entre a densidade básica da madeira e os ensaios de simulação dos pisos em uso.

ABSTRACT This study aimed to determine the basic density of the wood and to simulate the performance of flooring produced with wood from five tropical species: Dipteryx odorata (Cumaru), Handroanthus spp. (Ipê), Hymenaea Courbaril (Jatobá), Astronium Lecointei (Muiracatiara), and Bowdichia virgilioides (Sucupira-Preta). Falling steel sphere, static and dynamic friction, indentation caused by loads applied in small areas, rolling load, and abrasiveness impact tests were simulated. The results were subjected to analysis of variance and Tukey’s test at 5% significance, and Pearson’s correlation was performed between the basic density and the indexes of each flooring. The basic density of the wood flooring made from the evaluated species ranged from 0.735 to 0.958 g.cm-3. D. odorata, Handroanthus spp. and H. courbaril woods were classified as heavy, while those of A. Lecointei and B. Virgilioides as moderately heavy. It was possible to indicate D. odorata, Handroanthus spp., H. courbaril, and B. Virgilioides flooring for environments with intense traffic where there is dragging or falling objects such as industries and companies. The A. Lecointei flooring can be used in residential environments with light traffic, where the loads exerted are low. There was a correlation between the basic wood density and the flooring use simulation tests.

Resumo O uso e os custos de produtos de madeira sólida estão diretamente ligados ao grau de qualidade da matéria-prima. O mercado moveleiro é exemplo disso, pois quanto melhor a qualidade superficial da madeira, maior será seu valor comercial. Conhecer o comportamento da madeira durante o processo de usinagem é um importante parâmetro para caracterizar e dar usos específicos para cada espécie. Assim, o objetivo do presente estudo foi avaliar a qualidade da superfície da madeira de clones de Toona ciliata M. Roemer var. australis, seus potenciais usos após o processo de usinagem e definir, entre os clones avaliados, o de melhor qualidade superficial. Para isso, foram selecionadas trinta e cinco árvores (7 clones x 5 repetições) de um plantio localizado na região sul de Minas Gerais, das quais retirou-se toras de 1m de comprimento (0,3 a1,3 m a partir da base), e posteriormente desdobrando-se em tábuas. A secagem ocorreu nas condições ambientais de sombra e ao ar livre, até atingir a umidade de equilíbrio. O processo de usinagem (plaina e desengrosso) das tábuas ocorreu nas velocidades de avanço de 6 m.min-1 e 30 m.min-1. As avaliações da qualidade da superfície ocorreram de forma visual, conforme a norma ASTM D-1666 (2011) e pelo ensaio de rugosidade da superfície. Constatou-se que, dentre os sete clones estudados, o de número 1 apresentou maior qualidade de superfície na usinagem e, de modo geral, com o aumento da velocidade de avanço, houve redução da qualidade da superfície.

Abstract The use and costs of solid wood products are directly linked to the quality of the feedstock. One example is the furniture market, the better the surface quality of the wood is, the greater its commercial value is. Knowing the behavior of wood during the machining process is an important parameter to characterize and give specific uses for each species. Thus, the aim of this study was to evaluate the surface quality of wood from Toona ciliata M. Roemer var. australis clones, its potential uses after the machining process and to define, among the evaluated clones, the one with the best surface quality. Thus, thirty-five trees (7 clones x 5 repetitions) were selected from a plantation located in the southern region of Minas Gerais state, from which 1m long logs were removed (0.3 to 1.3 m from the base), and later unfolding on boards. Drying took place in the shade and outdoors, until equilibrium humidity was reached. The machining process (planer and thicknessing) of the boards took place at the forward speeds of 6 m.min-1 and 30 m.min-1. The evaluations of the surface quality took place visually, according to the ASTM D-1666 (2011) standard and by the surface roughness test. Among the seven clones studied, the number 1 presented higher surface quality in machining and, in general, with the increase in the forward speed, there was a reduction in surface quality.

Abstract: This study aims to evaluate the free and bound water flows in the different axes of Corymbia citriodora wood during drying. Wood samples were taken from the inner and outer regions of the tree stem from seven-years-old experimental plantations. The blocks were prepared for the water flow to occur in each wood axis and they were dried up to the final moisture content of 12%. Free water (FWFR), bound water (BWFR) and total water (TWFR) flow rates were calculated. The relationship between loss of moisture content and time presented an exponential curve, especially in the radial and tangential wood axes. Water flow in the three wood directions presented higher FWFR than TWFR (which was higher than BWFR). Free water flow was ~10 times higher than adsorbed water flow, considering values for moisture content between ~80% to ~12%. Free water movement in the longitudinal direction of the wood was ~2 times greater than in the radial axis and ~3 times greater than in the tangential axis. Bound water movement in the longitudinal direction of the wood was ~2 times greater than in the transverse direction. Bound water flow in the radial axis of the wood was statistically equal to the one in the tangential axis. The results indicate that the intensity of free and bound water flows changes according to the direction of Corymbia citriodora wood.

Abstract: This study aimed to determine the wood density using destructive and non-destructive sampling methods in a eucalypt hybrid clonal and determine the best point for the non-destructive sampling of the tree. A 5,6-year-oldEucalyptus urophylla x Eucalyptus grandis hybrid clone, from an energetic forest, was used, planted in the municipal district of Martinho Campos, MG, Brazil. The trees were sampled by three methods of destructive sampling. The traditional method (0%, 25%, 50%,75% and 100% of the commercial height Hc); alternative method (2%, 10%, 30% and 70% Hc) and via a meter by meter method starting from a height of 1,30 m from the soil (DBH). Three non-destructive sampling methods were also appraised: Resistograph®, Pilodyn® and 22 mm diameter cores at a DBH. The use of the Resistograph® at the 1,10 m or 1,50 m points and the Pilodyn® at 1,50m of height from the soil results the best correlations with the basic density determined by the three destructive sampling methods considered.

ABSTRACT Proposing technological innovations in the investigation of the structure and behaviour of wood is important to optimize its use. The assimilation of methods diffused in other areas, such as particle image velocimetry (PIV), can allow a rich range of information for different aspects. The aim of this study was to estimate the Young’s modulus using the PIV technique, independently of the wood density. The Young modulus value was obtained by universal testing machine, transversal vibration and PIV technique. Cedrela spp. and Eucalyptus cloeziana wood specimens were analyzed and their Young modulus were compared and correlated. The PIV technique presented mean Young’s modulus values statistically equal to those of the universal testing machine. The standard error of prediction from PIV approach was 0.46 and 0.97 GPa for Young’s modulus estimates for Cedrela spp. and Eucalyptus cloeziana wood, respectively.

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 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.

ABSTRACT This study aims to evaluate the use of Hovenia dulcis wood to produce Edge Glued Panels – EGP. To this end, joints with dimensions of 5.0 × 31.0 × 2.5 cm (Width × Length × Thickness) were put together using polyvinyl acetate (PVAc) and emulsion polymer isocyanate (EPI) adhesives at a spread rate of 200 g.m-2 and the chemical characterization of the wood was performed. The strength of glued joints was evaluated through shear tests based on the procedures described by established standards. The results showed that the EPI adhesive achieved the best results in edge gluing to produce EGP. The use of PVAc adhesive did not show satisfactory results for edge gluing under these conditions. Hovenia dulcis wood is indicated for producing higher value-added wood products - (VAWP) for external use purposes.

Abstract The effect of planting density on the anatomical characteristics of wood is still matter of debate. The aim of the study was to investigate the influence of planting density on the variation of wood anatomical elements in Eucalyptus and Acacia trees cultivated in areas of high planting density (monospecific) and low planting density (mixed) stands. The fiber length, fiber width, fiber lumen diameter, cell wall thickness, vessel diameter and vessel frequency were evaluated. The measurements were made from wood discs taken from five Eucalyptus urophylla x E. grandis trees and five Acacia mangium trees grown in high planting density (monospecific plantations, 1667 trees/ha) and in low planting density (mixed stands, 500 trees/ha), totalizing 20 trees at 4.5 years old. Eucalyptus and Acacia produced wood with shorter fibers and smaller vessels in high density stands, when compared to its equivalent in low density. Acacia presented more frequent vessels and fibers with walls thicker than its equivalent in low planting density. Eucalyptus presented longer and thinner fibers and vessels more frequent than Acacia, regardless of planting density. On the other hand, in high planting density, Acacia presented fibers with walls thicker than Eucalyptus and in low density of planting their vessels were larger.

Resumen El efecto de la densidad de plantación sobre las características anatómicas de la madera aún es tema de debate. El objetivo de este estudio fue investigar la influencia de la densidad de plantación sobre la variación de elementos anatómicos de la madera de árboles de Eucalyptus y Acacia, creciendo en áreas de alta densidad de plantación (monoespecífica) y en rodales de baja densidad de plantación (mixta). Se evaluaron: longitud, ancho y diámetro de lumen de la fibra, grosor de pared celular, diámetro y frecuencia de vasos. Las mediciones se hicieron en rodajas de madera tomadas de cinco árboles de Eucalyptus urophylla x E. grandis y cinco de Acacia mangium, creciendo en alta densidad de plantación (plantaciones monoespecíficas, 1667 árb/ha) y de otro tanto igual de árboles creciendo en baja densidad de plantación (rodales mixtos, 500 árb/ha), lo que hace un total de 20 árboles de 4.5 años de edad. Eucalyptus y Acacia de rodales de alta densidad produjeron madera con fibras más cortas y vasos más pequeños en comparación con sus equivalentes en baja densidad de plantación. Eucalyptus presentó fibras más largas y delgadas y vasos más frecuentes que Acacia, independientemente de la densidad de plantación. Acacia presentó vasos más frecuentes y fibras con paredes más gruesas que su equivalente en plantación de baja densidad. Por otro lado, en alta densidad de plantación, Acacia presentó fibras con paredes más gruesas que Eucalyptus y en baja densidad de plantación sus vasos fueron mayores.

RESUMO Em fábricas de móveis, o corte de painéis de fibras de média densidade (MDF) gera altas concentrações de particulados suspensos no ar, que dependendo de suas dimensões podem atingir áreas sensíveis do aparelho respiratório dos trabalhadores. O objetivo desse trabalho foi testar um método para medir dimensões de partículas oriundas do corte de painéis de madeira. O experimento foi desenvolvido em duas fábricas de móveis, de pequeno porte, em Lavras/MG. Durante o corte de painéis MDF foram coletadas e medidas partículas suspensas no ar, por meio de microscopia óptica. Os dados obtidos mostraram uma condição crítica no ambiente de trabalho, com elevadas concentrações de partículas pequenas (< 10 µm), que podem se alojar nos pulmões dos trabalhadores. O processo de medição das partículas demonstrou-se preciso e de fácil execução. Também, observou a importância de investimentos em exaustores (EPC) e, ou respirador tipo PFF2 (EPI), para a proteção dos trabalhadores.

ABSTRACT In furniture factories, the cutting of medium density fiberboard (MDF) generates high concentrations of particulates suspended in the air, which, depending on their dimensions, can reach the sensitive areas of the respiratory tract of workers. The aim of this study was to test a method to measure particle sizes derived from the cutting of wood paneling. The experiment was conducted in two small furniture factories located in the municipality of Lavras, Minas Gerais state, Brazil. During the cutting of MDF, airborne particles were collected and measured by means of optical microscopy. The data obtained showed a critical condition in the work environments, with high concentrations of small particles (<10 microns), which could be lodged in the workers’ lungs. The particle measuring process proved to be accurate and easy to perform. In addition, it is worth noting the importance of investment in personal protective equipment (PPE) such as hoods and/ or PFF2 dust masks for the protection of workers.

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 A norma ASTM D 1666-11 (AMERICAN SOCIETY FOR TESTING AND MATERIALS - ASTM, 2011) classifica a qualidade da superfície de peças de madeira, após o seu processamento mecânico, embora essa classificação seja difícil de ser realizada visualmente e o uso de algumas ferramentas, como o laser de estado sólido, pode facilitar tal classificação. Assim, o objetivo foi avaliar o uso da técnica sunset laser para qualificar superfícies processadas mecanicamente com qualidades visuais semelhantes. Utilizou-se a tora da base de uma árvore de Khaya ivorensis e outra de K. senegalensis, ambas com 11 anos. Foram confeccionados 22 corpos de prova de dimensões 600x140x30 mm (CxLxE) de cada espécie. Os corpos de prova foram aplainados com velocidades de 2400, 3600 e 4000 min-1 e as velocidades de avanço foram pré-determinadas em 6 e 15 m.min-1. Em seguida, os corpos de prova foram iluminados com a técnica sunset laser e fotografados na alta resolução, as imagens foram transferidas para o software Image J. Para avaliar a qualidade da superfície pela técnica sunset laser utilizou-se as áreas de defeitos na madeira que são classificadas como regular e ruim pela norma ASTM D 1666-11 (ASTM, 2011). Houve diferença de classificação dos defeitos da madeira entre os dois métodos utilizados, sendo que 31 corpos de prova classificados como regular pela análise visual, 8 deles foram classificados como ruim pelo método do laser. A utilização do laser de estado sólido na técnica sunset laser mostrou-se mais eficiente para avaliar pequenas diferenças de defeitos da madeira processada mecanicamente em comparação com a avaliação visual.

ABSTRACT The ASTM D 1666-11 (2011) norm classifies the quality of wood surface pieces after its mechanical processing. Although this classification is difficult to achieve visually, the use of some tools, such as solid state laser, can facilitate this classification. The aim of this work was to evaluate the use of sunset laser to qualify mechanically processed surfaces with similar visual qualities. We used a log from the base of a Khaya ivorensis tree and one from a K. senegalensis tree, both 11 years old. 22 specimens of dimensions 600x140x30 mm (CxLxE) were made of each species. The specimens were flattened with speeds of 2400, 3600 and 4000 min-1 and advanced speeds were predetermined in 6 and 15 m.min-1. Then the samples were illuminated with sunset laser and photographed at high resolution, the images were transferred to the software Image J. To evaluate the sunset laser, areas of defects in wood that are classified as regular and bad by ASTM D 1666-11 (2011) were used. There was a difference in classification of wood defects between the two methods used, from the 31 specimens classified as regularly by visual analysis, 8 of them were classified as bad by the laser method. The use of solid-state laser in the sunset laser technique was more efficient in evaluating small differences in mechanically processed wood defects compared to visual evaluation.

RESUMO Pisos de madeira maciça possuem características de resistência mecânica que permitem sua utilização em determinado tipo de tráfego. A densidade e dureza do material são os principais indicadores de desempenho do tipo de madeira, mas devido a sua natureza, ela esta sujeita a riscos, danos por queda de objetos, arraste, desgaste por tráfego de pessoas, os quais afetam a sua estética, desempenho, entre outros. Espécies nativas provenientes da Amazônia são as principais usadas no Brasil para a fabricação de pisos de madeira, no entanto, existem espécies oriundas de reflorestamento com potencial de utilização para este tipo de uso. Ensaios de simulação em serviço se constituem em importante ferramenta de avaliação da qualidade de pisos de madeira como forma de antecipar à resposta em termos de desempenho em uso. Nesse sentido, este trabalho foi conduzido com o objetivo de avaliar o comportamento em serviço de pisos de madeira jovem de Tectona grandis a partir de ensaios de simulação em laboratório e recomendar o tipo de tráfego possível para a utilização desta madeira, visando subsidiar uma utilização potencial desse material na fase juvenil, que é amplamente plantado no Brasil. Realizaram-se ensaios de simulação em serviço (ASTM D2394-05) por meio de avaliação da resistência a esforços de carga rolante, endentação aplicada em pequenas áreas, impacto da esfera de aço, abrasão, determinação do coeficiente de atrito e rugosidade da superfície. Os resultados determinaram resistência baixa para endentação e impacto da esfera de aço, resistência moderada a esforços de carga rolante e resistência satisfatória para abrasão com potencial de utilização em tráfego leve a moderado para uso doméstico. O acabamento influenciou no coeficiente de atrito e na rugosidade da madeira

ABSTRACT Hardwood floors has mechanical strength characteristics that allow its use in certain types of traffic. The basic density and hardness of the material are the main wood type of performance indicators, but due to its nature, it is subject to risks, damage by falling objects, drag, wear foot traffic, which affect its aesthetic and performance. Native species from the Amazon are the main used in Brazil for the manufacture of wood floors, however there are species from reforestation with potential use for this type of use. Simulated serving tests constitute an important quality assessment tool wood floors as a way to anticipate the response in terms of performance. In this sense this work was performed in order to evaluate the behavior in service of young hardwood floorsTectona grandis and thus support the potential use of this species widely planted in Brazil. There were simulated in-service testing (ASTM D2394-05) by evaluation of resistance to rolling load, indentation applied in small areas, falling-ball indentation, abrasion, friction coefficient, and determining surface roughness. The results showed low resistance to indentation applied in small areas and falling-ball indentation, moderate resistance to rolling load, favorable resistance to abrasion with potential for use in light to moderate traffic for domestic use. Finishing influenced the friction coefficient and surface roughness of wood.

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%.

Atualmente, há uma busca incessante pela qualidade dos ambientes industriais. Estudos demonstram que o desenvolvimento e o envolvimento dos trabalhadores em programas de qualidade nas indústrias trazem muitos benefícios administrativos, produtivos e pessoais. Nesses programas de qualidade, encontram-se as condições de conforto nos ambientes de trabalho, principalmente com relação à temperatura. No Brasil, é obrigatório que ambientes de trabalho tenham condições adequadas, sem que ocorram riscos de sobrecarga térmica aos trabalhadores. A avaliação quantitativa da sobrecarga térmica é feita pelo Índice de Bulbo Úmido Termômetro de Globo (IBUTG). O objetivo deste trabalho foi avaliar o IBUTG e as condições térmicas no setor de corte de MDF, situado em uma fábrica de móveis. A avaliação da exposição ocupacional ao calor foi realizada utilizando-se aparelho medidor de stress térmico digital, além de técnicas da segurança do trabalho e de higiene ocupacional. A avaliação consistiu em utilizar temperaturas provenientes de termômetros de bulbo úmido, bulbo seco e de globo. De posse dessas temperaturas e do tipo de atividade desenvolvida pelo trabalhador, no posto de trabalho, foram analisadas as condições térmicas locais. Os resultados demonstraram que, com relação à temperatura e à atividade, os funcionários não estão expostos à sobrecarga térmica, ou seja, o ambiente não é insalubre para o agente físico calor. Já com relação ao conforto térmico, esse ambiente de trabalho não foi considerado adequado. As temperaturas efetivas avaliadas ficaram acima dos limites definidos pela ergonomia ambiental.

Currently, environmental quality in industrial areas has been relentlessly pursued. Studies show that the development and involvement in quality programs in many industries bring about productive, administrative and personnel benefits. These quality programs include comfort conditions in the workplace, particularly with respect to temperature. In Brazil, it is mandatory for workplaces to present suitable conditions, with no risk of thermal overload to workers. Quantitative evaluation of thermal overload is performed by the Wet Bulb Globe Thermometer (WBGT) Index. The objective of the present study was to evaluate the WBGT and thermal conditions in the MDF cutting area of a furniture factory. The assessment of occupational exposure to heat was determined using a digital thermal stress meter and techniques of workplace safety and occupational hygiene. The evaluation consisted of analyzing the temperatures from the wet bulb, dry bulb, and globe thermometers. The local thermal conditions were analyzed based on these temperatures and on the type of activity performed by employees in their workplaces. The results showed that, with respect to temperature and type of activity, employees are not exposed to thermal overload, that is, the environment is not unhealthy regarding the physical agent heat; however, the work environment was not considered appropriate with regard to thermal comfort. The effective temperatures evaluated were above the limits set by environmental ergonomics.