Web-edge detection in the calender of a paper machine
Paper production process uses Calenders to improve the surface smoothness of the final product including printed newspaper, books or brochure paper. Although, while operating the calender, it should be ensured that the movement of the paper web in the calender is exactly executed in one line. Failing to do so can cause the heated calender roller pressed directly onto the coating of the opposite roller, thereby damaging it. To avoid the repairing and maintenance costs for this damage, it is important to control the position of the web edge.
Bestech Australia presents laser line sensors from Micro-Epsilon that help in transferring the exact position of the web edge directly to the machine control system. The sensor measures both edges of the web, determines the web width and transmits the measured value to the next stage of the trimming process. The sensor is very compact in size and doesn’t need to be removed and set up again while changing the rollers.
The laser line sensors are suitable for measurement on shiny metals or micro-machined surfaces with their oval-shape laser spot. Because of their spot size, the sensors can filter out the interference caused by surface roughness, defects, indentations and holes, which is generally in the case of micro-machined surfaces. Measurements performed by these sensors are also not affected by surface structures.
Sensor technology used: