| 摘要 |
Method for the operation of a production plant to produce an extrudate, by extruding, in at least one extruder whose screw rotation rate is variable, at least one layer of the extrudate composed of plastic, where the velocity of the extrudate (linear velocity) is variable, and moreover by measuring the diameter and/or the wall thickness of the layer by using a measuring head at a distance from the extruder, characterized by the following steps: - in an extruder model in a computer, an algorithm is stored to calculate diameter values and/or wall thickness values of the layer, taking into account the rotation-rate-dependent output performance of the extruder, the internal diameter of the layer and the linear velocity, - the extruder model is generated from the volume output (extruder performance) via measurement of the wall thickness and/or of the diameter, the extruder rotation rate, the linear velocity and the internal diameter and/or the core diameter, - during production of the extrudate, the extruder model calculates, for an internal diameter, a linear velocity, a screw rotation rate of the extruder and rotation-rate-dependent data for the output performance of the extruder, the value predictable as generated by the extruder for diameter and/or wall thickness, - the calculated, predictable value for diameter and/or wall thickness is indicated and - the calculated and indicated value for diameter and/or wall thickness is brought to the specified value for diameter and/or wall thickness via change in the screw rotation rate of the extruder and/or the linear velocity. |
