Molded Coils

Molded Coils

Molded coils are electric coils which have been enclosed in a thermoformed, vacuum formed or injection molded plastic casing. Similar and sometimes synonymous to encapsulated coils, molded coils are a type of electric coil, an essential component in solenoid valves, transformers, transducers, circuits, electric motors and many electronic household appliances. Made from conductive metal wire wrapped, or "coiled" into a specific diameter, electric coils  are "electromagnets", or magnets which are only activated to magnetism when introduced to an electrical current. Electric coils provide either movement or electric current transformation through electromagnetism.

An outer casing is used on electric coils which require protection from harsh environmental conditions such as moisture, salt, oil or vibration; with nothing to protect delicate copper coils from the elements, an electric coil's conductivity might be easily lost. Molded coils and encapsulated coils solve this problem in overlapping ways: molded coils are enclosed in injection molded or thermoplastic coverings which seal the entire coil unit, while encapsulated coils more often use liquid or thermoformed polymer epoxies. While these two overlapping types are often the same, "molded coils" more often refers to coils which are encased in hollow, thermoformed or injection molded plastic casings; encapsulated coils are often molded into liquid or thermoformed epoxies, the coil becoming one with its casing. Molded coils generally have hard, hollow casings which are good at protecting coils from harmful weather.

The design of molded coils offers superior weather resistance; many molded coils are entirely waterproof, allowing for a much broader diversity of applications. While some types of molded coils can be cost-effective alternatives to larger, more complicated structures, the tooling costs of manufacturing plastic parts in which to encapsulate molded coils often soar above the costs of impregnated coils, which have wire that has been directly epoxy or laminate-dipped and therefore require little or no tooling. Manufacturers choose molded coils, encapsulated coils or custom coils which best fit the application and manufacturing process at hand.