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Authors
Abstract(s)
Esta dissertação teve como objetivo o estudo de aditivos para melhorar o desempenho
da reciclagem de uma pasta kraft crua de Pinus sylvestris. Os aditivos em estudo neste
trabalho foram o amido catiónico (C Bond 35806 amostra industrial), bórax e a
carboximetilcelulose sódica. Primeiramente procedeu-se à desintegração da pasta crua
para a produção folhas de papel laboratoriais sem adição de aditivos com uma gramagem
de 60 g/m2
, num total de 200 folhas iniciais. Uma parte das folhas foi submetida aos
ensaios para a avaliação das suas propriedades físicas, as restantes foram novamente
desintegradas para dar início aos ciclos de reciclagem cujo procedimento se repete ao
longo de 5 ciclos. Em seguida iniciou-se o estudo de incorporação de aditivos, primeiro
com bórax onde se considerou a percentagem de 1% e tempo de contacto com a suspensão
fibrosa de 2h e 4h. De seguida preparam-se o amido catiónico a 3% e carboximetilcelulose
a 5% e 10% (cujas percentagens são relativas à massa seca de fibra celulósica). Depois de
preparadas as soluções dos aditivos, foram incorporadas nas suspensões de forma
individual e avaliadas as propriedades papeleiras. Com base nos resultados obtidos foram
estudadas as misturas 1% bórax 4 h + 3% AC, 1 % bórax 4 h + 5% CMC e 5% CMC + 3%
AC aplicadas nas suspensões fibrosas, produziram-se as folhas com os aditivos e
realizaram-se os ensaios de avaliação das mesmas. Este estudo permitiu selecionar dentre
elas, qual a mistura com os melhores resultados nas propriedades finais do papel, sendo
a mistura 5% CMC + 3% AC a selecionada. Esta mistura foi incorporada nos dois últimos
ciclos de reciclagem (4º e 5º ciclos), com o objetivo de avaliar e prolongar o número de
ciclos de reciclagem da pasta kraft crua de Pinus sylvestris, por meio do aumento da
resistência mecânica dos papéis produzidos.
This dissertation aimed to study additives to improve the recycling performance of raw kraft pulp from Pinus sylvestris. The additives under study in this work were cationic starch (C Bond 35806 industrial sample), borax and sodium carboxymethylcellulose. Firstly, the raw pulp was disintegrated to produce laboratory paper sheets without the addition of additives with a grammage of 60 g/m2 , in a total of 200 initial sheets. A portion of the leaves were subjected to tests to evaluate their physical properties, the remainder were disintegrated again to begin recycling cycles, the procedure being repeated over 5 cycles. Then the study of incorporating additives began, first with borax where a percentage of 1% and a contact time with the fibrous suspension of 2h and 4h were considered. Next, 3% cationic starch and 5% and 10% carboxymethylcellulose are prepared (the percentages of which are relative to the dry mass of cellulosic fiber). After the additive solutions were prepared, they were incorporated into the suspensions individually and the paper properties were evaluated. Based on the results obtained, mixtures of 1% borax 4 h + 3% AC, 1% borax 4 h + 5% CMC and 5% CMC + 3% AC applied to fibrous suspensions were studied, the sheets were produced with the additives and evaluation tests were carried out. This study made it possible to select, among them, the mixture with the best results in the final properties of the paper, with the mixture 5% CMC + 3% AC being selected. This mixture was incorporated into the last two recycling cycles (4th and 5th cycles), with the aim of evaluating and extending the number of recycling cycles of raw Pinus sylvestris kraft pulp, by increasing the mechanical resistance of the papers produced.
This dissertation aimed to study additives to improve the recycling performance of raw kraft pulp from Pinus sylvestris. The additives under study in this work were cationic starch (C Bond 35806 industrial sample), borax and sodium carboxymethylcellulose. Firstly, the raw pulp was disintegrated to produce laboratory paper sheets without the addition of additives with a grammage of 60 g/m2 , in a total of 200 initial sheets. A portion of the leaves were subjected to tests to evaluate their physical properties, the remainder were disintegrated again to begin recycling cycles, the procedure being repeated over 5 cycles. Then the study of incorporating additives began, first with borax where a percentage of 1% and a contact time with the fibrous suspension of 2h and 4h were considered. Next, 3% cationic starch and 5% and 10% carboxymethylcellulose are prepared (the percentages of which are relative to the dry mass of cellulosic fiber). After the additive solutions were prepared, they were incorporated into the suspensions individually and the paper properties were evaluated. Based on the results obtained, mixtures of 1% borax 4 h + 3% AC, 1% borax 4 h + 5% CMC and 5% CMC + 3% AC applied to fibrous suspensions were studied, the sheets were produced with the additives and evaluation tests were carried out. This study made it possible to select, among them, the mixture with the best results in the final properties of the paper, with the mixture 5% CMC + 3% AC being selected. This mixture was incorporated into the last two recycling cycles (4th and 5th cycles), with the aim of evaluating and extending the number of recycling cycles of raw Pinus sylvestris kraft pulp, by increasing the mechanical resistance of the papers produced.
Description
Keywords
Amido Catiónico Bórax Carboximetilcelulose Papel Propriedades Físicas do Papel Reciclagem