DOING WHAT THE CLIENTS ASK

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					                                                                                                                          quality
                                                                                                                measurement




                      By MARK WILLIAMSON

Reel density optimization systems installed on three of
Kondopoga’s machines have significantly reduced bottom waste


DOING WHAT THE CLIENTS ASK


                              F
                                       or some time now, paper web quality measure-           feedback measurement of nip loading nor precisely con-
                                       ments have been automatically controlled within        trolled arm movement. As a result, reeled-in density and
                                       very exact and miniscule tolerances. For instance,     tension is not usually uniform from the spool outward.
                              sheet caliper is often measured with one tenth of a mi-              With this expected and chronic waste near the spool,
                              cron precision – less than 1% of the width of human hair.       jumbo reels are built to a larger diameter purposely -
                              On the other hand, the macro-scale methods of building          and not so precisely- to meet winder set requirements.
                              a well-structured parent reel to exact tolerances needed        Normally, several centimeters of unusable paper on every
                              for the winders have been lagging behind somewhat,              jumbo reel are sent to the pulper.
                              especially on older machines.                                        Naturally, paper mills have been looking for more
                                   Without precision diameter measurements, opera-            precise and repeatable ways to measure and control the
                              tors have continued to use rough “measuring stick”              reeling process to produce jumbo reels with a maximum
                              techniques. Moreover, uncertain and inexact pneumatic           amount of usable paper built to the exact diameter and
                              controls of the primary and secondary arms have caused          sheet length needed for the winders.
                              a considerable amount of waste paper that cannot be slit
                              and wound reliably because of uneven tension and sheet          ADDING TO SALEABLE PRODUCTION
                              wrinkling. This reeling control problem is particularly
                              acute near the reel spool.                                      The Kondopoga mill has found a practical solution to this
                                   In many mills, such as the OAO Kondopoga news-             common industry problem with the commissioning of
                              print mill in the Karelia region of Russia, chronic “bottom     three automatic reel density optimization systems (ROS)
                              waste” or “left-on-spool” losses have been the most sig-        made by Vishay Nobel of Karlskoga, Sweden, on PM 8, 9
                              nificant contributor to dry end shrinkage losses. Paper-        and 10. Two more ROS projects are to be completed in
                              makers have been struggling to build an even reel with          early 2009 on PM 4 and 7. With the continuous use of these
                              older reeling systems which use pneumatic controls that         systems by the operators, the bottom waste on all three ma-
                              date back 20 or 30 years. In these older systems, there is no   chines has been reduced significantly, adding to saleable
                                                                                              production. At the same time, reel snap-off breaks have
                                                                                              been reduced or eliminated and the consistency of winding
                                                                                              density and wound roll sheet area yield has been improved.
                                                                                                   These results were accomplished without a major
                                                                                              reel rebuild. Instead, the primary and secondary arm
                                                                                              positioning and nip loading systems from were con-
The real-time progress
                                         
				
DOCUMENT INFO
Description: For some time now, paper Web quality measurements have been automatically controlled within very exact and miniscule tolerances. Without precision diameter measurements, operators have continued to use rough "measuring stick" techniques. Moreover, uncertain and inexact pneumatic controls of the primary and secondary arms have caused a considerable amount of waste paper that cannot be slit and wound reliably because of uneven tension and sheet wrinkling. This reeling control problem is particularly acute near the reel spool. In many mills, such as the OAO Krndopoga newsprint mill in the Karelia region of Russia, chronic "bottom waste" or "left-on-spool" losses have been the most significant contributor to dry end shrinkage losses. The Kondopoga mill has found a practical solution to this common industry problem with the commissioning of three automatic reel density optimization systems (ROS) made by Vishay Nobel of Karlskoga, Sweden, on PM 8, 9 and 10. The carry-through effect on winding density has some positive implications for the mill's customers.
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