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Advisor(s)
Abstract(s)
Os materiais compósitos termoplásticos têm vindo a experienciar um crescimento na
sua aplicação nos mais variados campos, como por exemplo: a indústria aeronáutica, a
indústria automóvel e até a indústria aeroespacial. Estes materiais apresentam-se como
viáveis alternativas face aos seus homólogos de matriz termoendurecível pois estes
últimos implicam algumas desvantagens na sua aplicação tais como: os tempos de ciclo
mais elevados, levando a uma redução na sua atratividade económica e/ ou a produção
de gases nocivos para o operador durante o processo de fabrico que os torna menos
atrativos do ponto de vista ambiental e económico; etc.
Com isto, a evolução desta classe de materiais tem sido notória, fruto do conhecimento
aportado pela investigação realizada. Comparados com os termoendurecíveis, no
entanto, apresentam alguns problemas relativos ao seu fabrico salientando-se a
dificuldade de impregnação das fibras por parte do polímero, problema que dificulta a
obtenção de um material devidamente consolidado o que leva a que as propriedades
mecânicas não sejam as desejadas.
Neste trabalho produziram-se pré-impregnados de matriz termoplástica por
impregnação em banho de polímero utilizando um equipamento disponível no
Laboratório de Materiais Compósitos do ISEP. Este material foi transformado em
compósitos consolidados utilizando equipamentos disponíveis no centro de
investigação TPAC (Thermoplastic Application Centre) sito na cidade de Enschede, nos
Países Baixos, e que tem como missão a aplicação de materiais compósitos de matriz
termoplástica de uma forma economicamente atrativa para pequenas e médias
empresas oferecendo uma infraestrutura quási industrial.
Para avaliar a qualidade do material pré-impregnado, este foi sujeito a ensaios de
calcinação e, após a sua transformação, foi sujeito a ensaios à flexão de modo a medir
as suas propriedades mecânicas. Os resultados obtidos foram comparados com modelos
teóricos e, apesar de terem ficado aquém das previsões, pode-se dizer que são
satisfatórios na medida em que permitem ser utilizados em aplicações comerciais
Thermoplastic composite materials have been experiencing growth in their application in the most varied fields, such as: the aeronautical industry, the automobile industry and even the aerospace industry. These materials are viable alternatives to their thermosetting matrix counterparts, which imply some disadvantages in their application, such as: longer cycle times, leading to a reduction in their economic attractiveness; the production of gases harmful to the operator during the manufacturing process; the impossibility of recycling and reprocessing, which makes them less attractive from an environmental and economic point of view; etc. With this, the evolution of this class of materials has been notorious, the result of the knowledge provided by the research carried out. Compared with thermosets, however, they present some problems related to manufacturing particularly the difficulty of impregnating the fibres with the polymer, a problem that makes it difficult to obtain a properly consolidated material, which hurts the mechanical properties. In this work, prepregs of thermoplastic matrix were produced by polymer bath impregnation using a proprietary machine available at the Composite Materials Laboratory of ISEP. This material was transformed into consolidated composites using equipment available at the TPAC (Thermoplastic Application Center) research center located in the city of Enschede, Netherlands, whose mission is to apply thermoplastic matrix composite materials in an economically attractive way for small businesses. and medium-sized companies offering a quasi-industrial infrastructure. To assess the quality of the pre-impregnated material, burn-off tests were conducted, and, after its transformation, bending tests to measure its mechanical properties. The results obtained were compared with theoretical models and, despite having fallen short of the predictions, it is reasonable to say that they are satisfactory insofar as they are suitable for usage in commercial applications
Thermoplastic composite materials have been experiencing growth in their application in the most varied fields, such as: the aeronautical industry, the automobile industry and even the aerospace industry. These materials are viable alternatives to their thermosetting matrix counterparts, which imply some disadvantages in their application, such as: longer cycle times, leading to a reduction in their economic attractiveness; the production of gases harmful to the operator during the manufacturing process; the impossibility of recycling and reprocessing, which makes them less attractive from an environmental and economic point of view; etc. With this, the evolution of this class of materials has been notorious, the result of the knowledge provided by the research carried out. Compared with thermosets, however, they present some problems related to manufacturing particularly the difficulty of impregnating the fibres with the polymer, a problem that makes it difficult to obtain a properly consolidated material, which hurts the mechanical properties. In this work, prepregs of thermoplastic matrix were produced by polymer bath impregnation using a proprietary machine available at the Composite Materials Laboratory of ISEP. This material was transformed into consolidated composites using equipment available at the TPAC (Thermoplastic Application Center) research center located in the city of Enschede, Netherlands, whose mission is to apply thermoplastic matrix composite materials in an economically attractive way for small businesses. and medium-sized companies offering a quasi-industrial infrastructure. To assess the quality of the pre-impregnated material, burn-off tests were conducted, and, after its transformation, bending tests to measure its mechanical properties. The results obtained were compared with theoretical models and, despite having fallen short of the predictions, it is reasonable to say that they are satisfactory insofar as they are suitable for usage in commercial applications
Description
Keywords
Materiais Compósitos Polímeros Termoplásticos Fibra de Carbono Polipropileno Pré-Impregnados Compressão a quente Consolidação in-situ Extrusão Impregnação por banho de polímero Matriz Termoplástica Compósitos Termoplásticos Composite materials Thermoplastic Polymers Carbon fibre Polypropylene Pre-Impregnated Hot compression In-situ consolidation Extrusion Polymer bath impregnation Thermoplastic Matrix Thermoplastic Composites