Development and evaluation of a vacuum casting process

Abstract

The vacuum casting process plays an important role in Rapid Prototyping. It provides the designer/manufacturer with the ability to reproduce plastic components from various types of prototypes. Casting under vacuum delivers components with a high degree of dimensional accuracy, free from unfilled cavities, in a wide spectrum of thermoset plastics, especially developed for this process. Components are cast in silicone moulds and cured at elevated temperatures to ensure specific characteristics of the cast component. The silicone moulds that are used in the process, are also produced under vacuum, cured and tempered at elevated temperatures to obtain reasonable mould life and to ensure specific characteristics of the cast components. The aim of this research project was to investigate the equipment required for the process and to evaluate the results that can be obtained by utilizing the process under local conditions. Various factors, such as the mould temperature, curing temperature, ambient temperature etc., playa role in the dimensional accuracy that can be obtained. The outcome of the research project would be to provide manufacturers w~h a framework that can be used in the vacuum casting process to reproduce components of the desired qual~y and dimensions.