Geração de finos no branqueamento de pasta kraft de eucalipto e seu efeito nas propriedades do papel
Carregando...
Data
2013-02-01
Autores
Comelato, Jaqueline Silveira [UNESP]
Ventorim, Gustavo [UNESP]
Caraschi, José Cláudio [UNESP]
Santos, Ivan Rodrigues dos [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade de Investigações Florestais
Resumo
Este trabalho teve por objetivo avaliar a quantidade de finos gerada por diferentes reagentes de branqueamento e seu efeito nas propriedades físicas e mecânicas da celulose kraft de eucalipto. A polpa foi branqueada por quatro sequências diferentes. Parte das amostras foi classificada em equipamento Bauer-McNett, sendo a parte não classificada (global) refinada para 40 ºSR, em moinho laboratorial PFI. As duas maiores porções de cada amostra proveniente da classificação foram também refinadas com o mesmo número de revoluções que a sua amostra global. Realizaram-se ensaios físicos e mecânicos das amostras refinadas, e suas fibras foram analisadas em equipamento FQA (Fiber Quality Analyser), antes e depois do refino. A maior quantidade de finos foi observada nas polpas refinadas e na sequência-referência. Os resultados de tração foram mais elevados e significativos nas amostras globais; as polpas classificadas não apresentaram diferença entre si, sendo atribuída a maior resistência à tração na presença de finos. A resistência ao rasgo foi afetada pelo comprimento das fibras e não pelo teor de finos. Os maiores valores de ascensão capilar Klemm ocorreram nas amostras classificadas em razão da ausência de finos e do maior comprimento de fibras.
The objective of this work was to evaluate the generation of fines by different bleaching reagents and its effect on physical and mechanical properties of eucalyptus kraft pulp. The pulp was bleached by four different sequences. Some of these samples was classified in Bauer-McNett equipment. The unclassified part of the pulp (global) was refined to 40ºSR in a laboratory PFI mill. The two major classified portions of each sample were also refined at the same revolutions as its global sample. Physical and mechanical tests were performed for both classified and unclassified samples, and their fibers were analyzed in FQA (Fiber Quality Analyzer), before and after refining.The greater amount of fines was observed for the refined pulp and the reference sequence. The tensile results were more significant for the global sample, classified pulps showed no difference between them being given the highest tensile strength to the presence of fines. The tear resistance was affected by the length of the fibers and not by the content of fines. The highest values of capillarity for the Klemm samples were classified due to the absence of fines and fibers of greater length.
The objective of this work was to evaluate the generation of fines by different bleaching reagents and its effect on physical and mechanical properties of eucalyptus kraft pulp. The pulp was bleached by four different sequences. Some of these samples was classified in Bauer-McNett equipment. The unclassified part of the pulp (global) was refined to 40ºSR in a laboratory PFI mill. The two major classified portions of each sample were also refined at the same revolutions as its global sample. Physical and mechanical tests were performed for both classified and unclassified samples, and their fibers were analyzed in FQA (Fiber Quality Analyzer), before and after refining.The greater amount of fines was observed for the refined pulp and the reference sequence. The tensile results were more significant for the global sample, classified pulps showed no difference between them being given the highest tensile strength to the presence of fines. The tear resistance was affected by the length of the fibers and not by the content of fines. The highest values of capillarity for the Klemm samples were classified due to the absence of fines and fibers of greater length.
Descrição
Palavras-chave
Classificação de fibras, Refino, Propriedades físicas e mecânicas, Fiber classification, Physical and mechanical properties, Refining
Como citar
Revista Árvore. Sociedade de Investigações Florestais, v. 37, n. 1, p. 181-189, 2013.