Influência do Desempenho Térmico de Moldes Fabricados com Compósito Epóxi/Alumínio nas Propriedades de PP Moldado por Injeção
Thermal Behavior of Epoxy/Aluminum Rapid Tooling Composite During Injection Molding of Polypropylene
Sabino Netto, Aurélio da C.; Villamizar, Felix A. Y.; Ahrens, Carlos H.; Salmoria, Gean V.
http://dx.doi.org/10.1590/S0104-14282008000300013
Polímeros: Ciência e Tecnologia, vol.18, n3, p.262-269, 2008
Resumo
O surgimento das tecnologias de prototipagem rápida (RP) e de ferramental rápido (RT) tem despertado interesse da indústria de moldes de injeção. O vazamento de termofixos com cargas metálicas possibilita a construção de moldes usando materiais compósitos, os quais apresentam maior resistência que os utilizados por outras técnicas RT. Neste trabalho foi estudado o comportamento térmico de moldes fabricados em epóxi/alumínio durante a injeção de polipropileno através de avaliações da estrutura e de propriedades mecânicas utilizando difração de raio X e ensaios de dureza e de tração. Os corpos-de-prova injetados no molde em compósito epóxi/alumínio apresentaram pequenas diferenças no grau de cristalinidade das superfícies analisadas e propriedades mecânicas semelhantes aos corpos-de-prova injetados em molde de aço. O estudo mostrou um razoável desempenho térmico do molde compósito durante a injeção de polipropileno evidenciando a viabilidade de utilização destes moldes na produção de pequenas séries de protótipos e de produtos neste termoplástico.
Palavras-chave
Desempenho térmico, molde compósito, moldagem por injeção de polipropileno
Abstract
Rapid prototyping (RP) and rapid tooling (RT) technologies are gaining increasing importance in the injection molding industry. Casting of resin/metal composites allows the construction of molds with greater resistance than those manufactured by other RT techniques such as Stereolithography. In this work, the thermal behavior of molds manufactured in epoxy/aluminum during the injection molding of polypropylene specimens was investigated. Structural and mechanical characterization of the molded specimens included X ray analysis, hardness and tensile testing. The samples presented small differences in the degree of crystallinity and similar mechanical properties in comparison with samples injected into steel molds. This study showed a reasonable thermal performance of the epoxy/aluminum mold during the injection molding of polypropylene, thus demonstrating the viability of using these molds to produce a few number of prototypes or products with this thermoplastic.
Keywords
Thermal behavior, composite mold, polypropylene injection molding
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