Method and device for the indirect determination of a specific formulation during extrusion

An extrusion process, comprising:

• extruding a first formulation using an extrusion device, said first formulation represents a specific formulation;
• measuring at least two processing parameters in said extrusion device, each by at least one sensor device in communication with a control unit,
• determining admissible deviation thresholds for each of said at least two processing parameters using said control unit,
• recording in a data base a characteristic curve of said first formulation in terms of said at least two processing parameters and said admissible deviation thresholds, thereby obtaining a finger print of said specific formulation that is specific for said extrusion device;
• extruding a second formulation using said extrusion device, said second formulation is intended to produce said specific formulation;
• measuring each of said at least two processing parameters particularly continuously or mainly continuously at defined spaced distant point of times;
• comparing a measured value of each of said at least two processing parameters with said finger print;
• and
• if each of said admissible deviation thresholds is not exceeded, continuing extruding said second formulation, or
• if at least one of said admissible deviation threshold is exceeded, generating an alarm signal,
• wherein:
• said characteristic curve comprises a ratio of said at least two processing parameters, and
• each of said admissible deviation threshold of said at least two processing parameters is a non-zero range of values that is correlated to the other in a rated manner.