Process and apparatus for thermally switching a body between a heating-up phase and a cooling-down phase for the treating of plastics

摘要

For the thermal treatment of plastics, a very thin heating film applied on a substrate is proposed. The current intensity in the heating film is controlled as a function of the average temperature of the heating film. Consequently, a plastic contacting the heating film can be heated up very quickly. After switching off the heating current, the plastic is cooled down very rapidly to the temperature of the substrate bearing the heating film. An application example which may be mentioned is the heat setting of blow-moulded hollow bodies of PET.