Apparatus employing integral dielectric heater for roll forming thermoplastic material

摘要

An apparatus for roll forming of thermoplastic material is provided which employs a pair of rollers having forming surfaces thereon, the pair of rollers defining a gap through which the thermoplastic material is to be passed during the forming operation, the thermoplastic material being dielectrically heated to a softening temperature as it passes between the rollers by a radio frequency electromagnetic field produced between the rollers by activating a radio frequency generator or oscillator which is electrically connected to one of the rollers, the rollers each having conductive portions between which the electromagnetic field is produced.