In principle, the resin component should be carefully stirred at the beginning of processing. Resins and hardeners are generally prepared and processed under vacuum. Adherence to the mixing ratio and intensive mixing are thus important since otherwise variations in the mechanical and dielectric properties of the cured potting resin can occur.
The casting method uses a liquid compound poured into a mold containing the device to be encased in. When the compound has hardened the mold is released. Components are normally treated with a high temperature and vacuum process to reach the desired stabilization. Resin and hardener are then generally injected in a dynamic mixer in order to be transferred by gravity or by pressure (A.P.G. automatic pressure gelation system) into molds already pre-heated. After the complete filling , molds are stored in adequate ovens to follow a selected curing cycle. If unfilled materials are used, during the process, a proper quantity of fillers can be added to the formulation before mixing.