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Desenvolvimento de um sistema adesivo para a produção de painéis de aglomerado de partículas com emissões ao nível da legislação E05
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Abstract(s)
O trabalho laboratorial visou a aplicação dos métodos normativos do perforador (ISO 12460-5) e da análise de gás (ISO 12460-3), referentes à determinação dos teores e emissões de formaldeído (TF e EF). Para o efeito, foram considerados como referência os valores limite utilizados como base de correlação numa unidade industrial da Sonae Arauco, correspondentes a 3,9 mg/100 g placa anidra e 2,4 mg/(m2·h) para a classe E05, respetivamente.
Ao longo da dissertação, executaram-se diversos estudos, entre eles: a influência do tratamento das partículas de madeira da CI (camada interna) com soluções de bissulfito de amónio e ureia, a modificação do sistema adesivo da CI e CE (camada externa) com aumentos do teor de melamina, resina, ureia e a utilização de diferentes formulações de resina. Adicionalmente, abordou-se a substituição do catalisador utilizado no sistema adesivo da CI, a introdução de um agente reticulante na CI com variação simultânea dos tempos de prensagem, o estudo da
influência de acondicionamento de provetes antes do teste de resistência à humidade (V313), e a adição de propilamina e do captador B ao sistema adesivo da CI. Entre as principais conclusões retiradas, é possível destacar a eficácia de atuação do bissulfito de amónio e da ureia, porém com enfraquecimento do desempenho mecânico. Verificou-se uma possível relação entre o aumento de melamina e a diminuição de emissões, acompanhada de melhorias nas propriedades mecânicas. Para além disso, observou-se a existência de
benefícios associados ao aumento do teor de ureia nos TF e EF, ainda que com tendência de estabilização, podendo verificar-se efeitos adversos a partir de determinados níveis de adição. Constatou-se uma aparente correspondência entre o aumento do tempo de prensagem e a eficácia do processo de cura, com diminuições significativas dos TF e EF e sem comprometimento evidente do desempenho mecânico. São ainda de relevância os resultados obtidos por adição de propilamina e captador B onde se verificou diminuições para metade do
teor de formaldeído. Em suma, na presente dissertação, e apesar da proximidade atingida, não foi possível satisfazer a nova legislação implementada para a classe E05.
This dissertation was carried out in collaboration with the company Sonae Arauco and the Instituto Superior de Engenharia do Porto. This work focused on the development of a formaldehyde-based resin system that allows the production of wood-based panels with emissions at the level of the E05 legislation, as defined by Commission Regulation (EU) 2023/1464. In the laboratory work the standardized Perforator (ISO 12460-5) and Gas Analysis (ISO 12460-3) Methods were used to determine formaldehyde content and emissions. Reference limit values were those used as a correlation baseline in an industrial unit of Sonae Arauco, corresponding to 3.9 mg/100 g oven dry board and 2.4 mg/(m2·h) for E05 class, respectively. The dissertation involved the execution of several studies, including: the influence of treating the core layer wood particles with ammonium bisulfite and urea solutions, the modification of the adhesive system used in both core and surface layers (CL and SL) through the increasing of melamine, resin, and urea contents, as well as the use of different resin formulations. In addition, the study addressed the substitution of the hardener used in the CL adhesive system, the incorporation of a crosslinking agent in the CL, combined with variations in pressing time, the effect of pre-conditioning test pieces prior to moisture resistance test (V313), and the incorporation of propylamine and a scavenger B into the CL adhesive system. Among the main conclusions drawn from the mentioned studies, the effectiveness of ammonium bisulfite and urea as additives was confirmed, although accompanied by a reduction in the mechanical performance. A possible association was found between increasing melamine content and reduced formaldehyde emissions, along with improvements in the mechanical properties. Additionally, increasing the urea content was associated with beneficial effects on formaldehyde content and emissions, although a tendency toward stabilization was observed, and adverse effects may occur beyond certain addition levels. Furthermore, an apparent association was also observed between longer press times and greater curing efficiency, resulting in significant reductions in formaldehyde content and emissions, without evident compromise to mechanical performance. It is also important to highlight that the addition of propylamine and scavenger B reduced formaldehyde content by approximately 50 %. Nonetheless, despite the advancements achieved in this study, compliance with the regulations established for the E05 class was not fully attained.
This dissertation was carried out in collaboration with the company Sonae Arauco and the Instituto Superior de Engenharia do Porto. This work focused on the development of a formaldehyde-based resin system that allows the production of wood-based panels with emissions at the level of the E05 legislation, as defined by Commission Regulation (EU) 2023/1464. In the laboratory work the standardized Perforator (ISO 12460-5) and Gas Analysis (ISO 12460-3) Methods were used to determine formaldehyde content and emissions. Reference limit values were those used as a correlation baseline in an industrial unit of Sonae Arauco, corresponding to 3.9 mg/100 g oven dry board and 2.4 mg/(m2·h) for E05 class, respectively. The dissertation involved the execution of several studies, including: the influence of treating the core layer wood particles with ammonium bisulfite and urea solutions, the modification of the adhesive system used in both core and surface layers (CL and SL) through the increasing of melamine, resin, and urea contents, as well as the use of different resin formulations. In addition, the study addressed the substitution of the hardener used in the CL adhesive system, the incorporation of a crosslinking agent in the CL, combined with variations in pressing time, the effect of pre-conditioning test pieces prior to moisture resistance test (V313), and the incorporation of propylamine and a scavenger B into the CL adhesive system. Among the main conclusions drawn from the mentioned studies, the effectiveness of ammonium bisulfite and urea as additives was confirmed, although accompanied by a reduction in the mechanical performance. A possible association was found between increasing melamine content and reduced formaldehyde emissions, along with improvements in the mechanical properties. Additionally, increasing the urea content was associated with beneficial effects on formaldehyde content and emissions, although a tendency toward stabilization was observed, and adverse effects may occur beyond certain addition levels. Furthermore, an apparent association was also observed between longer press times and greater curing efficiency, resulting in significant reductions in formaldehyde content and emissions, without evident compromise to mechanical performance. It is also important to highlight that the addition of propylamine and scavenger B reduced formaldehyde content by approximately 50 %. Nonetheless, despite the advancements achieved in this study, compliance with the regulations established for the E05 class was not fully attained.
Description
Keywords
Formaldehyde E05 Particleboards Perforator Gas Analysis Formaldeído Painéis de aglomerado de partículas Perforador Análise de gás