HiRun and SymRun Plus blow boxes helped UPM Schongau PM 7 to speed up by 50 m/min
“We don´t have edge wrinkles anymore”, says Josef Eder, Production Manager of UPM Schongau PM 7.
How to get rid of the edge wrinkles and speed up the machine The main target for the rebuild was to increase the paper machine production speed. Earlier, the speed was limited by edge wrinkles, especially in the area of the first dryer sections.
Metso Paper’s excellent blow box references from several paper mills convinced the customer thatthis technology would be the optimal solution for their machine as well. The high vacuums offered by HiRun boxes would obviously lead to better sheet stability at the beginning of the dryer section, eliminate the edge wrinkles and give more potential speed for the machine.
Installation of the new blow boxes to stabilize the sheet in the dryer section
The dryer section was rebuilt by Metso Paper in the summer of 2006. At the same time, modifications were made to the press section (nip load increase), resulting in a higher dryness level from the press. In the rebuild the existing original vacuum boxes were replaced by the new HiRun and SymRun Plus boxes. A total of 7 HiRun 2000 blow boxes were installed in the two first dryer groups and 8 SymRun Plus blow boxes in the 3rd and 4th dryer groups. The new SymRun Plus boxes were also equipped with the SingleForce Plus tail threading booster plates.
More speed – and no wrinkles
According to Josef Eder, Production Manager, PM 7, the targets of the investment were well achieved “We have been able to increase the machine speed by 50 m/min, which is a very good result. Our running speed is now 1,730–1,740 m/min. And wedon’t have edge wrinkles anymore.” “When we chose Metso Paper’s runnability system for our machine, the key issue affecting our decision was that it was known to be effective and proven technology with a lot of good references. Now we know that we made a good decision. We are very happy with this Metso delivery.”
UPM Schongau mill
The Schongau mill produces newsprint and uncoated paper with a high filler content for newspapers, newspaper supplements, advertisers, brochures, magazines and catalogues. The mill annually supplies up to 750,000 tonnes of printing paper to publishers and major printers all over the world. PM 7 is a Voith machine producing newsprint grades of 40–52 g/m2 at a speed level of 1,700 m/min. The machine width is about 8.5 m.
