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Abstract(s)
Esta dissertação de mestrado teve como principal objetivo o desenvolvimento de uma correlação entre dois métodos distintos usados para determinar o formaldeído em painéis de madeira: o método do perforador, que avalia o formaldeído extraído com tolueno, e o método da análise de gás, método este que avalia o formaldeído emitido pelo painel em condições controladas de temperatura, caudal de ar, pressão e humidade. Com este objetivo, foram analisadas várias amostras vindas das fábricas Sonae Arauco, tanto painéis de aglomerado (PB) como painéis de fibras de média densidade (MDF), de variadas espessuras, composições e classes. Obtiveram-se duas correlações, uma para painéis MDF com R2 de 0,9249 e outra para painéis PB com R2 de 0,7471. Dos dezanove resultados obtidos para painéis PB, seis deles não se encontram dentro do intervalo de confiança. Quanto aos resultados dos painéis MDF, três dos doze resultados estão fora do intervalo de confiança. Ambos os métodos estudados usam para a determinação do formaldeído em solução aquosa a reação de acetilacetona, pelo que foi feito um estudo do impacto das variáveis processuais relevantes, como a temperatura e o tempo de banho, o volume dos reagentes e a degradação fotocatalítica da diacetilidrolutidina (DDL). Verificou-se que a temperatura e o tempo de banho, dentro das gamas estudadas, não têm qualquer impacto na concentração de formaldeído. Já os volumes da solução analisada, volume de solução de acetilacetona e de solução de acetato de amónio são determinantes nos resultados de concentração de formaldeído final. Foi ainda estudada a produção de painéis de aglomerado de madeira para compreender em que extensão parâmetros como tempo, temperatura e pressão de prensagem, massa volúmica do painel e quantidade de resina (Fx) nas camadas interna e externa (CI e CE, respetivamente) poderiam afetar a emissão/teor de formaldeído. Neste sentido, foram realizados 18 ensaios, cada um com três réplicas. Concluiu-se que todos estes parâmetros influenciam o resultado da emissão/teor de formaldeído pelos painéis, alguns em maior extensão que outros.
This dissertation had as principal objective the development of a correlation between two different methods to evaluate the formaldehyde on wood panels: the Perforator Method which evaluates the extracted formaldehyde, with toluene, and the Gas Analysis Method which determines the released formaldehyde by wood panels in controlled conditions such as temperature, air flow, pressure and humidity. With this objective, it were analyzed samples that came from the Sonae Arauco factories such as particleboard panels (PB) and medium density fiberboard panels (MDF), with a wide range of thicknesses, compositions and classes. It was obtained two correlations, one for MDF panels with an R2 of 0,9249 and another one for PB panels with an R2 of 0,7471. From the nineteen results from PB panels, six of them weren’t on the confidence interval. Regarding the MDF panels’ results, three of the twelve results weren’t found on the confidence interval. Both methods that were studied use, for determination of the formaldehyde, the Acetylacetone Method. For that, it was studied the impact of some process variables suchlike temperature and bath time, reagents’ volume and photocatalytic degradation of DDL. It was concluded that the temperature and the bath time, within the range studied, didn’t have a nig impact on the formaldehyde concentration. On the other hand, the volumes of the solution to be analyzed, acetylacetone solution and the ammonium solution had an impact on the final formaldehyde concentration. Finally, it was studied the production of particleboard panels to comprehend the extension of some parameters for instance pressing time, temperature and pressure, panels’ density and quantity of resin (Fx) in the intern and external layers (CI and CE, respectively). The purpose of this study was to understand how these parameters affect the emission/content of formaldehyde. For this study, it was made eighteen trials, each one with three replicas. It was concluded that all the studied parameters affect the emission/content of formaldehyde, some more than others.
This dissertation had as principal objective the development of a correlation between two different methods to evaluate the formaldehyde on wood panels: the Perforator Method which evaluates the extracted formaldehyde, with toluene, and the Gas Analysis Method which determines the released formaldehyde by wood panels in controlled conditions such as temperature, air flow, pressure and humidity. With this objective, it were analyzed samples that came from the Sonae Arauco factories such as particleboard panels (PB) and medium density fiberboard panels (MDF), with a wide range of thicknesses, compositions and classes. It was obtained two correlations, one for MDF panels with an R2 of 0,9249 and another one for PB panels with an R2 of 0,7471. From the nineteen results from PB panels, six of them weren’t on the confidence interval. Regarding the MDF panels’ results, three of the twelve results weren’t found on the confidence interval. Both methods that were studied use, for determination of the formaldehyde, the Acetylacetone Method. For that, it was studied the impact of some process variables suchlike temperature and bath time, reagents’ volume and photocatalytic degradation of DDL. It was concluded that the temperature and the bath time, within the range studied, didn’t have a nig impact on the formaldehyde concentration. On the other hand, the volumes of the solution to be analyzed, acetylacetone solution and the ammonium solution had an impact on the final formaldehyde concentration. Finally, it was studied the production of particleboard panels to comprehend the extension of some parameters for instance pressing time, temperature and pressure, panels’ density and quantity of resin (Fx) in the intern and external layers (CI and CE, respectively). The purpose of this study was to understand how these parameters affect the emission/content of formaldehyde. For this study, it was made eighteen trials, each one with three replicas. It was concluded that all the studied parameters affect the emission/content of formaldehyde, some more than others.
Description
Keywords
ISO 12460-5 ISO 12460-3 Formaldeído PB MDF Formaldehyde