Efeito da vaporização na madeira de Eucalyptus grandis sobre as suas propriedades químicas e resistência natural a fungos e cupins
Carregando...
Data
2011-08-12
Autores
Rocha, Cinthia Dias [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A madeira de Eucalyptus grandis Hill ex Maiden submetida ao tratamento de vaporização apresenta maior qualidade na indústria de serrados e otimização durante o processo de secagem. O objetivo desta pesquisa foi verificar o efeito da vaporização em toras e em madeira serrada nas propriedades químicas e na resistência natural a fungo e cupins da madeira de Eucalyptus grandis. Para isso, foram empregados quatro tratamentos: material controle, madeira vaporizada em toras (vapor saturado, 20 horas à 90°C), madeira pré-vaporizada em tábuas (1 hora de aquecimento inicial seguida de 3 horas de vapor saturado a 90ºC) e material submetido às duas vaporizações, ou seja, tábuas pré-vaporizadas obtidas de toras vaporizadas. Para caracterização química foram utilizadas as normas TAPPI (1999); para determinar a resistência natural a fungo foram utilizados os procedimentos das normas ASTM D-1413 (1994) e ASTM D-2017 (1994) e, para cupim, a metodologia desenvolvida pelo Instituto de Pesquisas Tecnológicas (1980). Os resultados mostraram que: (1) a vaporização promoveu algumas modificações não estatisticamente significativas na composição química da madeira, como: acréscimos de até 5,07% do teor de solubilidade em NaOH 1%, decréscimos de até 21,80% no teor de solubilidade em água quente, acréscimos no teor de extrativos totais para madeira vaporizada em tora e aquela pré-vaporizada em tábuas na ordem de 4,80% e 9,50%, respectivamente, enquanto a madeira submetida à vaporização conjunta (vaporizada/pré-vaporizada) apresentou decréscimo de 7,10%; aumento de até 6,77% no teor de lignina Klason, e redução de até 4,75% no teor de hemiceluloses. Outras modificações, no entanto, foram significativas, como: redução de 3,10% no teor de holocelulose e de 5,06% no teor de celulose...
The steamed wood of Eucalyptus grandis Hill ex Maiden has a better quality to the sawn industry and optimizes the drying process The aim objective of this work was evaluate the effect of vaporization in logs and lumber on chemical properties and Eucalyptus grandis´s natural resistance to dry wood termites (Cryptotermes brevis) and to the fungus Pycnoporus sanguineus. For this, four treatments were used: control material, steamed wood logs (saturated steam, 20 hours at 90 ° C), pre-steamed wood on tables (1 hour initial warm-up followed by 3 hours of saturated steam at 90 º C) and materials that were submitted to two sprays, i.e., pre-steamed boards obtained from vaporized logs. For the chemical characterization was used TAPPI (1999), to determine the natural resistance to fungus were used procedures of ASTM D-1413 (1994) and ASTM D-2017 (1994) standards and, for termites, the methodology developed by the Instituto de Pesquisas Tecnológicas (1980). Results showed that: (1) vaporization promoted no significant modifications in the chemical composition of wood, such as additions of 5.07% in the level of solubility in NaOH 1%, solubility decrease of 21.80% in the level of solubility in hot water, increases in the total extractive content for the log wood and pre-vaporized boards in the order of 4.80% and 9.50% respectively, while the vaporized wood/pre-vaporized on boards showed a decrease of 7.10%; increase of 6.77% in Klason lignin content and reduction of 4.75% in the content of hemicelluloses. Other modifications, however, were significant, as reduction of 3.10% in the holocellulose content and 5.06% in cellulose content, (2) there was also no significant effect on the susceptibility of wood when vaporized and exposed to the white-rot fungus, Pycnoporus sanguineus. The steamed wood... (Complete abstract click electronic access below)
The steamed wood of Eucalyptus grandis Hill ex Maiden has a better quality to the sawn industry and optimizes the drying process The aim objective of this work was evaluate the effect of vaporization in logs and lumber on chemical properties and Eucalyptus grandis´s natural resistance to dry wood termites (Cryptotermes brevis) and to the fungus Pycnoporus sanguineus. For this, four treatments were used: control material, steamed wood logs (saturated steam, 20 hours at 90 ° C), pre-steamed wood on tables (1 hour initial warm-up followed by 3 hours of saturated steam at 90 º C) and materials that were submitted to two sprays, i.e., pre-steamed boards obtained from vaporized logs. For the chemical characterization was used TAPPI (1999), to determine the natural resistance to fungus were used procedures of ASTM D-1413 (1994) and ASTM D-2017 (1994) standards and, for termites, the methodology developed by the Instituto de Pesquisas Tecnológicas (1980). Results showed that: (1) vaporization promoted no significant modifications in the chemical composition of wood, such as additions of 5.07% in the level of solubility in NaOH 1%, solubility decrease of 21.80% in the level of solubility in hot water, increases in the total extractive content for the log wood and pre-vaporized boards in the order of 4.80% and 9.50% respectively, while the vaporized wood/pre-vaporized on boards showed a decrease of 7.10%; increase of 6.77% in Klason lignin content and reduction of 4.75% in the content of hemicelluloses. Other modifications, however, were significant, as reduction of 3.10% in the holocellulose content and 5.06% in cellulose content, (2) there was also no significant effect on the susceptibility of wood when vaporized and exposed to the white-rot fungus, Pycnoporus sanguineus. The steamed wood... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Eucalyptus grandis, Madeira - Imunidade natural, Madeira - Propriedades químicas, Log steaming, Pre-steaming, Wood - Natural resistance
Como citar
ROCHA, Cinthia Dias. Efeito da vaporização na madeira de Eucalyptus grandis sobre as suas propriedades químicas e resistência natural a fungos e cupins. 2011. ix, 121 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas de Botucatu, 2011.