Abstract
Inlay waxes were prepared for the use in complex castings, which have both the male portion of the pattern and the male portion of the die.The male portion of the wax pattern requires sufficient shrinkage to allow the layer of cement between the castings and the cavity.On the other hand, the shrinkage of the wax pattern at the male portion of the die is restricted by stress relaxation of the wax.The main component was paraffin with a high melting point and the others were carnauba wax, dammar and beeswax.Physical properties such as thermal expansion, flow and stress relaxation of these prepared waxes were investigated.The inlay wax having large shrinkage at the male portion of the pattern could be formulated using paraffin with a high melting point but without isoparaffin.In this case, it was necessary to add small amounts of paraffin with a low melting point in order to reduce the operational difficulty.Small amounts of carnauba wax, which restrict stress relaxation and suitable amounts of other ingredients, should be added to minimize the shrinkage of the wax pattern at the male portion of the die.
