idiamCONTROL simplifies wear detection in extruder bore holes

Micro-Epsilon: The idiamCONTROL sensor unit optimizes the maintenance of extruders by reliably detecting wear of housing bores. This non-contact method of inspection uses capacitive sensors that are arranged opposite to one another.

With compound extrusion lines, signs of wear occur in the 8-shaped bores as plastic granulate is conveyed via augers. The inner diameter over the total length is a benchmark for wear of the tubes. Regular maintenance intervals are therefore necessary in order to prevent expensive failures of such a plant. To date, maintenance of extruders has been a complex process carried out manually. The plant had to be dismantled in single extruder parts, viewed and subsequently reassembled. Wear detection using idiamCONTROL avoids complex dismantling and enables direct non-contact measurement of the inner diameter of the plant. The evaluation unit performs an axial position detection and therefore achieves the targeted replacement of defective segments. This means it is no longer necessary to replace the tubes on a preventive basis. This sensor unit significantly minimises maintenance time and is suitable for all metals without further calibration.

The idiamCONTROL sensor unit is guided mechanically and precisely measures the inner diameter of extruder bores in six tracks. Depending on the diameter, one or more capacitive sensors are installed. The sensor is moved via two cross rollers on both ends of the sensor which can be turned through 40° clockwise or anticlockwise. These rollers are spring-loaded, with several metal pins preventing the measuring cylinder from turning. This ensures reliable guidance within the bores in order to achieve precise measurement results.

The sensor unit is inserted into the tube. While retracting the sensor unit, the diameter measurements and the distance covered are recorded and stored. The signal is shown as a diameter over the complete tube length and tolerance deviations are displayed. Individual areas can be cut and zoomed in order to save or print these for documentation purposes.