Two ovens are necessary for vacuum casting. The first oven, which is permanently in operation, is for storing the resins, especially opened units, at a temperature of 35°C. This slight tempering prevents the resin from crystallising, this is especially important for isozynath-components.
A second oven is necessary, because a constant temperature of 70°C is required. The silicone moulds are pre-tempered at this temperature to enable perfect casting results. After the cast the silicone mould is put back into the oven, to temper the plastic part for reaching the optimal final strength.
For tempering the resins a standard oven is sufficient. The oven for tempering the mould should be equipped with ventilation to guarantee an optimal heat distribution.
In principle, the size of the oven should fit the size of the chamber. A system 2 XL with a maximum mould length of 2 meters requires an oven for parts up to 2 meters, otherwise large parts cannot be tempered. Depending on the resin used, this can lead to important strength problems and brittleness.
In order to avoid using a large and cost intensive oven for small moulds, it sometimes makes sense to purchase a third smaller oven for this purpose.