Apparatus and method for heating plastic preforms with controllable heating power

A method for heating plastic preforms, wherein a transport device transports the plastic preforms along a predefined transport path, wherein this transport device has a plurality of holding elements for holding the plastic preforms, and wherein at least one first heating section, which is arranged along the transport path, and at least one second heating section, which is arranged along the transport path downstream of the first heating section, heat the plastic preforms, wherein the heating sections each comprise a plurality of independently controllable heating elements which allow heating of the plastic preforms in several heating zones, lying above each other in the longitudinal direction of the plastic preforms, with a temperature profile which changes in the longitudinal direction of the plastic preforms, wherein a control device controls these heating elements, comprising the steps of:

• providing the apparatus with an input device via which the user can predefine a set value for a heating process, and with a processor device actuating the individual heating elements taking account of the set value, and actuating the individual heating elements taking into account a set value of at least one of the lamp power and a set value which is characteristic of the lamp power, and wherein a processor device automatically calculates whether and how many heating elements must be activated in which heating zone in response to an applied temperature specification by the user.