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Estudo de método alternativo para a determinação de produtos de acabamento em empresa produtora de fibras acrílicas
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Abstract(s)
O presente estágio curricular, realizado no âmbito da tese do mestrado em Engenharia
Biológica e Química, foi desenvolvido nas instalações da SGL Composites, S.A. no
Lavradio.
Esta tese teve como objetivo principal o desenvolvimento de um novo método de
determinação do teor de acabamento de fibras acrílicas pigmentadas, de forma a substituir o
método interno atual, método BEHR, podendo levar até oito horas totais, por uma
metodologia mais rápida e igualmente confiável.
O trabalho iniciou-se com um estudo dos conceitos teóricos de suporte a extrações solidolíquido e dos métodos adotados para uso interno no laboratório. Após a realização dos
estudos introdutórios iniciou-se a parte prática onde inicialmente se tentou desenvolver um
novo procedimento que apresente estabilidade e confiança nos resultados obtidos. Ao fim
de algumas tentativas e respetivos afinamentos foi desenvolvido um procedimento, ML4,
que engloba os procedimentos já existentes para a determinação de humidade e do teor de
acabamento pelo método Vortex. Este procedimento apresenta repetibilidade e, numa fase
inicial, conduziu a resultados significativamente próximos dos obtidos pelo método BEHR.
Seguiu-se a realização de múltiplos ensaios com o objetivo de validar o novo método. O
primeiro ensaio pretendeu avaliar a confiança dos resultados obtidos, tendo sido para isso
analisadas cinquenta fibras diferentes pelos dois métodos, BEHR e o método em
desenvolvimento, ML4. Os valores obtidos pelos dois métodos foram comparados utilizando
um software de analise estatística e que permitiu concluir que, não obstante o facto de os
valores não coincidirem, medida a medida, os resultados globalmente obtidos pelos dois
métodos eram estatisticamente semelhantes. A diferença de valores, caso a caso, não
permite, contudo, a validação do método. Foram, assim, efetuados mais ensaios, com vista
ao estudo da reprodutibilidade dos resultados, avaliação da diferença entre uma amostra
cardada ou não, entre outros. No final de todos os ensaios os resultados obtidos mostraramse inconclusivos, tendo-se obtido valores idênticos pelos dois métodos para umas fibras e
com diferenças muito significativas para outras.
No final dos ensaios não foi possível validar o método desenvolvido devido à falta de
coerência e repetibilidade do mesmo. O trabalho irá ser continuado, já fora do âmbito deste
estágio, dadas as inúmeras possibilidades que ainda precisam de ser exploradas. Foram
levantadas algumas hipóteses para justificar as diferenças obtidas, como a do pigmento
utilizado na fibra ter alguma influência na remoção do acabamento pelo método
desenvolvido, por exemplo.
The present curricular internship, conducted as part of the master’s thesis in Biological and Chemical Engineering, was carried out at the facilities of SGL Composites, S.A. in Lavradio, Portugal. The primary objective of this thesis was to develop a new method for determining the finish content of pigmented acrylic fibers, aiming to replace the current internal method, the BEHR method, which can take up to eight hours in total, with a faster yet equally reliable methodology. The work began with a theoretical study to support solid-liquid extraction concepts and the methods currently adopted for internal use in the laboratory. Following this introductory study, the practical component started, initially focused on developing a new procedure that ensures stability and reliability in the results obtained. After several attempts and corresponding adjustments, a new procedure (ML4) was established, incorporating the existing method for determining moisture and finish content, the Vortex method. This procedure, ML4, demonstrated repeatability and, in the initial phase, yielded results significantly close to those obtained with the BEHR method. Subsequently, multiple trials were conducted to validate the new method. The first trial aimed to evaluate the reliability of the results, analyzing fifty different fiber samples using both the BEHR method and the method under development, ML4. The values obtained by the two methods were compared using statistical analysis software, which allowed the conclusion that, although the values did not match on a case-by-case basis, the overall results of the two methods were statistically similar. However, the case-by-case differences did not permit validation of the method. Further trials were conducted to explore reproducibility, the differences between carded and uncarded samples, and others. At the conclusion of all the trials, the results were inconclusive, with some fibers producing similar values across both methods, while others showed significant discrepancies. In the end, it was not possible to fully validate the developed method (ML4) due to its lack of consistency and repeatability. The work will continue outside the scope of this internship, given the numerous possibilities that still need to be explored. Some hypotheses were raised to justify the observed differences, such as the potential influence of the pigment used in the fibers on the removal of the finish by the developed method, for example.
The present curricular internship, conducted as part of the master’s thesis in Biological and Chemical Engineering, was carried out at the facilities of SGL Composites, S.A. in Lavradio, Portugal. The primary objective of this thesis was to develop a new method for determining the finish content of pigmented acrylic fibers, aiming to replace the current internal method, the BEHR method, which can take up to eight hours in total, with a faster yet equally reliable methodology. The work began with a theoretical study to support solid-liquid extraction concepts and the methods currently adopted for internal use in the laboratory. Following this introductory study, the practical component started, initially focused on developing a new procedure that ensures stability and reliability in the results obtained. After several attempts and corresponding adjustments, a new procedure (ML4) was established, incorporating the existing method for determining moisture and finish content, the Vortex method. This procedure, ML4, demonstrated repeatability and, in the initial phase, yielded results significantly close to those obtained with the BEHR method. Subsequently, multiple trials were conducted to validate the new method. The first trial aimed to evaluate the reliability of the results, analyzing fifty different fiber samples using both the BEHR method and the method under development, ML4. The values obtained by the two methods were compared using statistical analysis software, which allowed the conclusion that, although the values did not match on a case-by-case basis, the overall results of the two methods were statistically similar. However, the case-by-case differences did not permit validation of the method. Further trials were conducted to explore reproducibility, the differences between carded and uncarded samples, and others. At the conclusion of all the trials, the results were inconclusive, with some fibers producing similar values across both methods, while others showed significant discrepancies. In the end, it was not possible to fully validate the developed method (ML4) due to its lack of consistency and repeatability. The work will continue outside the scope of this internship, given the numerous possibilities that still need to be explored. Some hypotheses were raised to justify the observed differences, such as the potential influence of the pigment used in the fibers on the removal of the finish by the developed method, for example.
Description
Keywords
Fibras acrílicas pigmentadas Extração solido-líquido Teor de acabamento Metodologia de Randall Pigmented acrylic fibers Solid-liquid extraction Finishing content Randall methodology