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.
