material with a high dielectric constant, the electric fields for heating plastics production.

摘要

Apparatus for heating a plastic sheet uses a high dielectric constant material (HDCM) to shape an RF electric field (14) to be either concentrated or uniform as desired depending upon the object to be formed from the sheet (16). Electrodes (12a, 12b) can be annular with a circular or elliptical cross-section or be plates or wires, and can be disposed in the HCDM or exterior of the HCDM. A process for heating a plastic material comprises generating an RF field and shaping the field near the material using high dielectric constant members.