Condition Based Monitoring of Converting Line Equipment

Abstract: Condition Based Monitoring techniques have been developed to monitor the condition of critical components in machines. The most widely used technique to detect damage in machine components is vibration monitoring, but there are areas where other methods could be a better option. Vibration measuring can also be used as a broader search for damage in components while other methods can specify the exact location and type of damage. Other CBM methods can be oil analysis, thermography, utltrasonics, Motor Current Signature Analysis, electrical testing and Coast Down Time. The purpose of this master thesis is to define critical components in Tetra Pak converting machines, investigate possibilities of applying CBM techniques and to recommend and set up solutions for both converting lines. To gather and analyze break down statistics, in the hope of identifying critical components, the software QlikView was used. Unfortunately, this did not give a better idea of the problem areas and another approach had to be taken; critical components were identified based on the cost for obtaining new parts and the lead time for them to be delivered. In this way two critical areas were identified; the drives in the extruder and printing stations. The decision was to online monitor these drives with vibration measurements and different companies with online vibration monitoring systems were consulted. What company to use is difficult to say before executing test installations of the systems and analyses of the results, but all companies were willing to provide this service. Placement of transducers on the components has been suggested. Variable rotational speeds, various diameters of cliché rolls and different print patterns in the printing stations can become a problem when teaching the system “normal vibrations”, but this can be solved by triggering the system to only measure during specific conditions and process parameters. Another problem can be large thrust bearing in the extruder stations, which rotates with low rotational speed. This can probably be solved by using special shock pulse techniques for measuring at low rotational speeds or oil analysis on the return oil from the thrust bearing.