Modern induction heating systems quickly heat the inserts from the outside surface, limiting the heat energy to the outer edges where heat is needed to reflow the plastic. Longer heating cycles may result in the softening of the internal threads, especially at the low temperatures needed for heating brass inserts. Heating with induction is reliable, repeatable, non-contact and energy-efficient. Solid state systems, when used in conjunction with temperature sensing and control equipment, are capable of heating very small areas within precise production tolerances.
Typical RF power supplies for metal to plastic bonding range from 1 to 20kW, depending on the parts and application requirements.
Metal to plastic bonding is one of several plastic reflow applications for induction heating. Other processes involving heating plastic to a liquidous state include metal reclaiming and thermoplastic composite manufacturing. Ambrell has extensive experience with induction heating used for injection molding and heat staking of threaded metal inserts into plastic.