Bamboo as a raw material for the paper industry: studies of three cooking processes with Bambusa tuldoides Munro

brag Bragantia Bragantia 0006-8705 1678-4499 Instituto Agronômico de Campinas Campinas, SP, Brazil A comparison was made of three cooking processes - soda, soda-sulfur, and neutral sodium sulfite - using four different amounts of alkalis to extract the pulp from Bambusa tuldoides Munro. Yields superior to 50% were obtained in the majority of cookings; but they decreased when 20% or more of NaOH, in relation to the dry weight of chips, were employed. The highest rate of pulp to raw material was obtained with the neutral sodium-sulfite process. The paper produced was highly porous, very good in the tearing and reasonable in folding, tensile-and bursting strength. Bambu como matéria prima para papel — Estudo de processos de cozimento em material de Bambusa tuldoides Munro Bamboo as a raw material for the paper industry — Studies of three cooking processes with Bambusa tuldoides Munro Dirceu Ciaramello Engenheiro-agrônomo, Seção de Plantas Fibrosas, Instituto Agronômico SINOPSE Três processos de cozimento — soda, soda-enxôfre e sulfito neutro de sódio — com várias dosagens de reagente, foram estudados para a obtenção de pasta crua para papel, com material de Bambusa tuldoides Munro. Os maiores rendimentos foram obtidos com o sulfito neutro, seguido do soda-enxôfre. O emprego exclusivo da soda, em dosagem igual ou superior a 20% do pêso sêco dos cavacos, trouxe queda no rendimento. Nos testes físico-mecânicos, os papéis se mostraram altamente porosos e resistentes ao rasgo, mostrando-se o material promissor na produção de pasta não branqueada, semelhante a "kraft" de pinheiros. As diferenças, entre os diversos cozimentos, com relação às características do papel foram pouco acentuadas. Para aprodução de celulose branqueada, o processo soda-enxôfre, com 22% de NaOH e 2,2% de S, foi o mais promissor. SUMMARY A comparison was made of three cooking processes — soda, soda-sulfur, and neutral sodium sulfite — using four different amounts of alkalis to extract the pulp from Bambusa tuldoides Munro. Yields superior to 50% were obtained in the majority of cookings; but they decreased when 20% or more of NaOH, in relation to the dry weight of chips, were employed. The highest rate of pulp to raw material was obtained with the neutral sodium-sulfite process. The paper produced was highly porous, very good in the tearing and reasonable in folding, tensile-and bursting strength. Texto completo disponível apenas em PDF. Full text available only in PDF format. LITERATURA CITADA Recebido para publicação em 12 de fevereiro de 1969. 1. CAMUS, E. G. Les bambusées. Paris, Lechevalier, 1931. 2v. Les bambusées 1931 2 CAMUS E. G. 2. HAIDAR, R. Mensagem. Boletim ABCP, Săo Paulo, 1(9):3, 1967. Mensagem Boletim ABCP 1967 3 9 1 HAIDAR R. 3. ISTAS, J. R. & RAEKELBOOM, E. L. Étude biométrique, chimique et papetičre des bambous du Congo. Bruxelles, I.N.E.A.C. 1962. 53p. (Série techniques 67) Étude biométrique, chimique et papetière des bambous du Congo 1962 53 67 ISTAS J. R. RAEKELBOOM E. L. 4. REDKO, B. V. P. & MAZZEI, F. M. Celulose do bambu. Boletim ABCP, Săo Paulo, 1(7):9-14, 1967. Celulose do bambu Boletim ABCP 1967 9 14 7 1 REDKO B. V. P. MAZZEI F. M. 5. RAITT, W. The digestion of grasses and bamboo for papermaking. London, Technical Press, 1931. 116p. The digestion of grasses and bamboo for papermaking 1931 116 RAITT W.