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Authors
Abstract(s)
A aplicação de revestimentos em sistemas aeronáuticos é imperativa para a sua operação numa vasta gama de condições ambientais. Estes revestimentos conferem propriedades que permitem proteger a superfície metálica contra o aparecimento precoce de corrosão, assim como características especiais, como tornar a aeronave indetetável aos radares de forças inimigas, no caso das militares.
Até à data, na indústria aeronáutica, foram utilizados maioritariamente os compostos de crómio hexavalente nos processos de pintura, devido às suas propriedades anticorrosivas e baixo custo. Todavia, surge necessidade para a sua substituição, devido a exibir elevados níveis de toxicidade e ser reconhecido como um carcinogénico humano via inalação.
Este trabalho estudou a viabilidade de substituição de primários utilizados na pintura de aeronaves na OGMA por outros que satisfaçam o regulamento relativo ao registo, avaliação, autorização e restrição de substâncias químicas, que foi criado para restringir o uso de substâncias prejudiciais à saúde humana e ao ambiente na União Europeia.
Com os resultados obtidos foi possível constatar que os primários alternativos testados para o setor militar, comparativamente aos com crómio hexavalente, são inviáveis economicamente. Isto deve-se ao facto de apresentarem um preço superior, uma capacidade de cobertura inferior e uma espessura requerida maior, o que por sua vez aumenta consideravelmente a quantidade de primário necessário para pintar uma aeronave.
Por outro lado, o primário alternativo do setor civil testado mostrou rivalizar todos os parâmetros considerados, relativamente ao primário com crómio hexavalente. Isto leva-nos a concluir que, no presente, embora haja uma oferta de primários alternativos qualificados no mercado, apenas alguns reúnem todos os atributos necessários para serem implementados. A dificuldade em substituir substâncias em sistemas já estabelecidos, devido à complexidade dos mesmos, da sua cadeia de abastecimento e aos longos períodos de aprovação, fazem com que seja somente viável implementar tais primários em sistemas em desenvolvimento. Recomenda-se num futuro estudar a implementação de um pré-tratamento de superfície compatível com as operações da empresa, a implementação de sistemas automatizados de pintura de forma a reduzir o impacto da exposição no fator humano.
The application of coatings in aeronautical systems is imperative for their operation in a wide range of environmental conditions. These coatings confer properties that allow the metal surface to be protected against the early appearance of corrosion, as well as special features such as rendering the aircraft undetectable to the radars of enemy forces, in the case of the military. Until now, in the aeronautical industry, chromium hexavalent Cr(VI) compounds have been broadly used in painting schemes due to their anticorrosive properties and low cost. Nonetheless, there is a need for their replacement due to exhibiting high levels of toxicity and being recognized as a human carcinogen via inhalation. This work studied the feasibility of replacing primers used in aircraft painting at OGMA by others that comply with REACH Regulation, which was created to restrict the use of substances harmful to human health and the environment in the European Union. With the results obtained, it was possible to verify that the alternative military primers tested, compared to the one containing Cr(VI), are economically unfeasible. This is due to the fact that they have a higher price per liter, a lower coverage capacity and a greater required thickness, which in turn greatly increases the amount of primer required to paint an aircraft. On the other hand, the alternative primer of the civil sector tested proved to rival all the considered parameters relative to the primer with Cr(VI). This leads us to conclude that at present, although there is qualified alternative primers in the market, only a few have all the attributes necessary to be implemented. The difficulty of replacing substances in already established systems, due to their complexity, supply chain and long approval periods, makes it only feasible to implement such primers in systems in development. It is recommended in the future to study the implementation of a surface pretreatment compatible with the company's operations, the implementation of automated painting systems in order to reduce the impact of exposure on the human factor.
The application of coatings in aeronautical systems is imperative for their operation in a wide range of environmental conditions. These coatings confer properties that allow the metal surface to be protected against the early appearance of corrosion, as well as special features such as rendering the aircraft undetectable to the radars of enemy forces, in the case of the military. Until now, in the aeronautical industry, chromium hexavalent Cr(VI) compounds have been broadly used in painting schemes due to their anticorrosive properties and low cost. Nonetheless, there is a need for their replacement due to exhibiting high levels of toxicity and being recognized as a human carcinogen via inhalation. This work studied the feasibility of replacing primers used in aircraft painting at OGMA by others that comply with REACH Regulation, which was created to restrict the use of substances harmful to human health and the environment in the European Union. With the results obtained, it was possible to verify that the alternative military primers tested, compared to the one containing Cr(VI), are economically unfeasible. This is due to the fact that they have a higher price per liter, a lower coverage capacity and a greater required thickness, which in turn greatly increases the amount of primer required to paint an aircraft. On the other hand, the alternative primer of the civil sector tested proved to rival all the considered parameters relative to the primer with Cr(VI). This leads us to conclude that at present, although there is qualified alternative primers in the market, only a few have all the attributes necessary to be implemented. The difficulty of replacing substances in already established systems, due to their complexity, supply chain and long approval periods, makes it only feasible to implement such primers in systems in development. It is recommended in the future to study the implementation of a surface pretreatment compatible with the company's operations, the implementation of automated painting systems in order to reduce the impact of exposure on the human factor.
Description
Keywords
Aeronautical Chromium Hexavalent. Coating Painting Primer Reach Regulation