Aplicação de enzimas, extração e adição de hemiceluloses combinadas com ondas ultrassônicas para desenvolvimento de propriedades de papéis reciclados

• Autor(a) principal: Silva, Juliana Cristina da
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3062
• topic: Enzimas; Hemiceluloses; Papéis reciclados; Enzymes; Hemicelluloses; Recycled aper; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::TECNOLOGIA E UTILIZACAO DE PRODUTOS FLORESTAIS

The objective of this study was to evaluate the capacity recoverability of the properties of the papers formed from scraps of corrugated post-consumption by combining different techniques. Was studied the effects of the action of different enzymes, extraction and addition of hemicelluloses, refining in PFI mill and ultrasonic and combination of these technologies on the paper properties formed. The verification of the modifications of the potential papermaking and pulp was done through morphological analysis and hygroscopic properties of pulps and through physical and mechanical tests of the roles formed after undergoing the aforementioned technologies. Also was evaluated the capacity of reduction of components of micro and macro stickies through enzymatic treatments and the effects of these treatments before and after the refining in PFI mill; the potential of ultrasound waves to recover the properties of recycled papers, their possible use and operation in joint with the conventional mechanical refining to process and comparative analysis of energy consumption between the two refining technologies; ultrasonification of the pulp combined with the addition of hemicelluloses. The results showed that the mode of action of diverse types of enzymes reflected in differences in the characteristics of the pulps analyzed and led to gains in strength in the physical and mechanical properties of the pulps without the need for combination with other techniques. The enzymes were able to reduce unwanted components and causing of stickies that make up the pulp coming from post-consumer scraps, thus reducing so the potential of stickies. The enzymatic treatment after the refining was more effective in improving recovery of strength characteristics of papers, showing generally, higher values than the treatment prior to refining. The results also showed that technology of ultrasonification was able to develop the properties of recycled paper, although paper properties that relate directly to the links interfibers showed be more further developed by refining in PFI. The treatment time, energy consumption and production capacity appeared to be the major problems of ultrasonic technology in case of equipment used in this study. Still been verified that both the combination of refining in mill PFI with enzymatic treatments as the combination of ultrasonic and enzymatic treatments were effective in the development of papers properties evaluated. The filtered / effluent generated from the enzymatic treatments had values exceeding the limits established by law for release in water bodies, but when they were not mixed with other effluents from the process it was observed that the subsequent effluents had chemical and physical caracteristcs within the range allowed by law. The recirculation of filtered / effluents did not result in reduction of paper properties when compared with papers formed without recirculation. Finally, it was found that deposition of hemicelluloses occurred in the pulps submitted to refining in mill PFI, ultrasound and without refining being that the treatment in PFI mill provided the best conditions for the retention of the hemicelluloses dosed. The ultrasonic treatment followed by the addition of hemicelluloses showed be efficient in the development of mechanical strength properties of paper, promoting the development of properties, however, less pronounced than that observed when the pulp was refined in mill PFI followed by the addition of hemicelluloses. The pulp with lower content of hemicelluloses refines much more slowly than the containing a higher content of hemicelluloses.