The lower press felt in the wet end of a paper mill producing newsprint paper showed a remarkable shrinking after only two weeks of production: Both lateral edges reduced the width of the felt, thus the lifetime of the felt decreased dramatically. After two weeks of production it had to be replaced. Usually the lifetime should be five weeks. In addition to the increased spare costs the production department suffered from further machine downtimes. On the picture to the right the compact structure of the wet end can be seen clearly. In this multi layer environment an optical system can only be used under a huge loss of time and accuracy caused by the additionally needed measurement equipment like mirrors and prisms. Here PARALIGN® was able to convince production management by its incomparably brief measurement time and its self explaining measurement protocol. Another advantage: PARALIGN® does not need any line of sight between the rolls themselves or between the rolls and the outer reference line. Thus all rolls could be measured without a loss of accuracy. After measuring the alignment condition, the found offsets were corrected according to the immediately available PARALIGN® protocol. Flawless forming? LEVALIGN® Flatness measurement with the better partner. Contact us for further information. The lower press roll was chosen as reference roll. The corrections were proved on the same day by a second PARALIGN® measurement. After the corrections the lower press felt could keep its planned lifetime as the shrinking effect did not occur any more. The next page shows the PARALIGN® protocols of the discussed wet end before and after the corrections. The improvement in roll parallelism can be seen clearly. Advantages of PARALIGN® in the wet end Longer lifetime of consumables: wires, felts, roll covers Higher machine availability reduction in paper breaks rare replacement of parts results in reduced stoppages Increased quality decrease in folds uniform moisture profile less waste www.pruftechnik.com

After alignment Before alignment Roll face length: 7000 mm Your point of view is the operator side of the machine, represented in green. The machine side is represented in red. The blue marked drying cylinder is chosen as reference roll, it is perpendicular to the drawing. For further information please see www.paralign.info PRÜFTECHNIK Alignment Systems GmbH Freisinger Str. 34 85737 Ismaning Germany Tel +49 89 99616-0 Fax +49 89 99616-100 [email protected] www.pruftechnik.com A member of the PRÜFTECHNIK Group PARALIGN® and LEVALIGN® Ultra are registered trademarks of PRÜFTECHNIK Dieter Busch...