Web-edge detection in the calender of a paper machine

If movement of the paper web in the calender is not exactly executed in one line, the heated calender roller is pressed directly onto the coating of the opposite roller, which can damage it. Repairing this special coating or even replacing the whole roller would be very costly, which is why it is mandatory to control the position of the web edge. This is where laser line sensors from Micro-Epsilon are utilised, transferring the exact position of the web edge directly to the machine control system.