High performance thermoplastics for coil forms

The development of high performance thermoplastic resins such as liquid crystal polymers and high temperature polyamides, with melting points in the 300/spl deg/C range, has opened up a broad range of new opportunities for thermoplastics in coil form applications formerly limited to thermosets. These materials are now used to encapsulate coils employed in high temperature environments. Modified thermoplastic PET, PET, and PA 66 resins tailored for coil form applications are also entering the marketplace. This paper surveys the thermoplastic resins available to the engineer and molder and outlines the most suitable applications for each. On a global scale, the efforts of technical committees such as TC-98 of the IEC and individual agencies such as Underwriters Laboratories are strengthening the international standards framework for coil form applications. This paper also discusses how the available thermoplastic resins for coil forms fit into this framework.