Among the several applications that require the resin-bonding or the vacuum casting, there are also electric motors, whose insulation is absolutely necessary to grant them very long duration. Air bubbles or resin gaps can diminish the motor insulation, damaging performances and service life. Moreover, a partial discharge between the ground and primary insulation can occur.
Another reason for avoiding bubbles is the decrease of the heat dissipation, provided by resin and essential for the long service life of the motor and the preservation of high performances. Therefore, the resin must be “forced” into all inner spaces of the motor (especially in undercuts and in windings). The only possible procedure is vacuum casting.
Demak, thanks to its vacuum casting system, can assure the total absence of air in resin (by means of efficacious degassing systems) and in finished products, too. Then, all dispensing systems used in these process types are equipped with vacuum cabins, but not only: Demak technology for vacuum degassing starts from the resin loading on the machine until the last dispensing time. An efficient vacuum dispensing process, together with epoxy resin featuring high thermal resistance, allows qualifying motors for all durability tests required by OEM.