Systems and methods for controlling the operation of a blow molder are disclosed. An indication of a crystallinity of at least one container produced by the blow molder may be received along with a material distribution of the at least one container. A model may be executed, where the model relates a plurality of blow molder input parameters to the indication of crystallinity and the material distribution and where a result of the model comprises changes to at least one of the plurality of blow molder input parameters to move the material distribution towards a baseline material distribution and the crystallinity towards a baseline crystallinity. The changes to the at least one of the plurality of blow molder input parameters may be implemented.

A method for producing containers made of thermoplastic material from preforms. In example embodiments, the method includes comparing a thickness measurement with a stored thickness setpoint, by use of a control unit, and modifying an electrical power of at least two rows of radiation sources while keeping the sum of the electrical powers being supplied to all rows of radiation sources the same, by use of the control unit, if the measured thickness is different from the thickness setpoint. A computer program product and data processing device using the method is also disclosed.