Dual Loop Strategy maximizes quality on extrusion lines
Wherever several ZUMBACH systems are used in combination, remarkable successes can be achieved in DLP measurement and control.
Considerable thought should always be given to investing in several high precision and reliable control technologies within the extrusion line. After all, global material costs are rising just as fast as quality requirements. Whether it is quality improvement for very precise cables or further material savings for commodity tubing – with the ZUMBACH hot end dual loop control strategy, the extrusion can be monitored and controlled even more precisely and quickly.
The unique and cost-effective process exploits the benefits of ultrasonic measurement and perfects it in combination with laser scanner technologies.
The intelligent solution offered by the ZUMBACH control strategy makes allowance for the product’s properties at the hot and cold ends of the line. It utilises data from the diameter measurement, determined from the ultrasonic eccentricity and wall thickness scanner UMAC®. These data measurements are automatically adjusted based on the data from the ODAC® laser diameter scanner at the end of the line and evaluated.
This creates a very fast control feedback loop (due to the short distance from the point of change to the point of measurement) while still basing the control decisions on the final diameter measurements.
Using this dual loop, transient deviations can be minimised, in turn leading to a significant reduction in standard deviation and ultimately an increase in the process capability index (CPK).
Picture: Dual Loop configuration with UMAC® at the hot end, and ODAC® at the cold.