Thermoforming (free blowing) of poly(ethylene terephthalate) preforms was successfully and quickly performed in a rotating system designed for dielectric hysteresis heating. Temperature profile modeling was carried out with the amorphous poly(ethylene terephthalate) permittivity at different temperatures. The Maxwell and heat equations were used to determine the best profile and power tuning. The determination of the theoretical boundary conditions was accomplished by the adjustment of the numerical transient external surface wall temperature with experimental infrared pyrometry results. In comparison with infrared, microwaves allowed high power density absorption inside the perform wall without a dramatic temperature gradient. Consequently, the heat blowing stage could be accelerated, and the process took at least 5 times less energy than infrared heating. Industrial applications involve the integration of the molding step and the design of the overall process. (C) 2008 Wiley Periodicals, Inc.