Encapsulation of sensors, solenoids and transformers with engineering thermoplastics

Driven by soaring demand for encapsulated solenoids, particularly for automotive applications, and the environmental need to eliminate potting in the manufacture of some transformers, engineering thermoplastics are moving rapidly into a wide range of encapsulation applications. Small, high volume coils and components are being encapsulated with polyamide (PA) nylon 66, PA 612 nylon, and polyethylene terepthalate (PET) and polybutylene terephthalate (PET) polyesters. New high temperature nylons (HTNs) are being used in encapsulating higher performance coils, and encapsulation with liquid crystal polymers (LCPs) is being developed. Thermoplastic compression molded sheet is finding use in the encapsulation of distribution transformers in the 3 to >100 kilovolt-ampere (kVA) range