Die optimisering van die posisie van modelle in silikoongietvorms vir die roteringsgietproses

Abstract

The spincasting process is currently used mainly for casting of low melting point materials for products such as costume jewellery and fashion items where dimensional accuracy is not very important. The shrinkage of the products during the casting process plays an important role in their dimensional accuracy. Some of the factors that play a role in the magnitude of the shrinkage are the temperature of the material, temperature of the mould, spin speed and clamping pressure. Centrifugal and inertia forces acting on the casting process has the effect that the shrinkage factor changes in the different directions. This study investigated the factors that play a .role in the accuracy of the products were investigated. The extent to which the shrinkage influences the final product is investigated. This information is required by the designer to compensate in the design for the amount of shrinkage so that the final product will have the needed accuracy. The shrinkage factors of the models were investigated at the different casting parameters to determine their influence. In conclusion this study shows that a constant shrinkage factor can not be determined since each set of parameters produce their own shrinkage factor. It is suggested that this information should be used to dejermine a shrinkage factor for a certain set of casting parameters. This shrinkage factor can then be used in the design to obtain the required accuracy in the cast part.