ERCIM News No.36 - January 1999

IQTension - Revealing Uneven Tension Profiles of Paper Reels

by Hannu Linna

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In June 1998 Valmet Automation launched its IQTension product at the PulPaper ‘98 fair in Helsinki. IQTension provides a new method of revealing uneven tension profiles in cross direction (CD-profiles) of paper reels before they can cause any harm at the printing press. The system was developed by Valmet’s various units in close collaboration with VTT Information Technology. Valmet is one of the world’s leading supplier of paper and board machinery and related process control. So far Valmet Automation has sold nine IQTension systems, mostly to paper mills outside Finland. The first device was installed at Helprint Quebecor Oy, the largest rotogravure printing house in the Nordic countries.

According to VTT Information Technology’s research results, the tension profile of the paper reel is an important quality property. There is a clear interdependency between the tension profile and the runnability of paper and thus also the amount of paper wasted at the printing press. The difference in the amounts of wasted paper is enormous when comparing good and bad paper reels. A large rotogravure printing house can lose tens or even hundreds of tons to wasted paper because of poor tension profiles meaning great economical loss.

During the development of Valmet’s IQTension, the tension profiles of over 5,000 paper reels were measured at the Helprint Quebecor rotogravure printing house. The experiment revealed that the tension profile affected both the reel’s break sensitivity and the amount of paper wasted during the printing process. The tension profile’s minimum value measured at the beginning of the reel was the most critical factor for the number of breaks. During a run, the number of breaks depended considerably on how unbalanced the overall shape of the tension profile was. There are significant variations in the papers supplied by different manufacturers. The larger the fluctuations in the tension profile, the higher are the percentages of breaks. Harri Sundell, Production Manager at Helprint Quebecor Oy commented: “This product marks the beginning of a new era. Papermakers and printers can collaborate and use the information supplied by IQTension to achieve better quality in printing and less paper wastage”.

 

VTT has modelled the interdependencies between the different paper properties as well as the interactions between paper characteristics and runnability. The software, which makes it possible to take into consideration also properties measured across the web (CD-profiles), is currently customised for research purposes. It will, however, be developed into a practical tool with applications in every-day production. VTT Information Technology is a pioneer on a global scale as far as advanced research into the runnability of paper on paper machines and printing presses is concerned. VTT is also studying how greater advantage can be taken of the enormous amount of data measured from paper.

The first IQTension device installed in a paper mill is at UPM-Kymmene Corporation’s Kaipola mill, where it has successfully improved both production efficiency and paper quality. The installation is also being exploited for research purposes.

IQTension was recently awarded the ATIP (Association Technique de l’Industrie Papetière) innovation prize at the ATIP 51st Annual Meeting in Grenoble, France. The ATIP innovation prize has been awarded four times. This year more than 30 products were competing for the prize.

Please contact:

Hannu Linna - VTT Information Technology
Tel: +358 0 456 5253
E-mail: Hannu.Linna@vtt.fi