Efeito das características anatômicas e químicas na densidade básica da madeira e na qualidade da polpa de clones hibridos de Eucalyptus grandis x urophylla

• Autor(a) principal: Queiroz, Simone Cristina Setúbal
• Data de Publicação: 2002
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3216
• topic: Madeira; Densidade; Anatomia; Química; Polpa de madeira; Propriedades; Qualidade; Eucalyptus; Wood; Density; Anatomy; Chemistry; Wood pulp; Properties; Quality; Eucalyptus; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::TECNOLOGIA E UTILIZACAO DE PRODUTOS FLORESTAIS

This study aimed to evaluate the effect of the chemical and anatomic characteristics on wood density and on physical- mechanical properties of eucalyptus kraft pulp. Two eucalyptus clones with different basic densities (450 and 550 kg/m³) were studied. For each clone, a disk was removed from the trunk at 50% commercial height and sample was taken from this disk at 75% distance from medulla to bark direction for anatomical studies. Fiber dimensional characteristics were determined for both woods. Kraft cookings were corried out by using different of alkali charges to obtain pulps with kappa number 18±0.5. The pulps were bleached by ODEopDD sequence to get 90±1%ISO, refined and their optical and physical-mechanic properties were tested. The higher wood density showed thicker walls fibers, smaller diameter lumen, higher frequency of smaller diameter vases, as well as a smaller empty spaces area (lumen). This same wood presented greater difficulty for delignification, resulting in lower yield and viscosity. For bleaching, the low density wood presented lower reagent requirement to reach 90±1%ISO final brightness. The mechanical and structural properties of hand made sheets showed no significant differences. After refining, the optic properties presented some differences, being more sensitive to the differences in the basic densities. In this study it was demonstrated that wood basic density was correlated to the wood anatomical characteristic, but not to its chemical composition.