Voith has upgraded and successfully commissioned the paper machine PM 53 at Holmen Paper in Braviken, Sweden. The PM 53 can now produce various paper grades ranging from newsprint to sophisticated SC papers, including the recently developed Holmen UNIQ SC paper. This paper grade in the basis weight range 43 – 50 g/m2 is suitable for magazines, catalogs and advertising supplements.
As part of the three-week upgrade, Voith replaced the former EcoSoft calenders with a Janus MK 2 calender. The special design of this calender, featuring a 45° incline of the roll stack, meant that the existing Nipco rolls could be reused while achieving a 40 percent higher line load. The MasterReel reel winder was relocated for reasons of space and fitted with a LunaReel rubber roll cover, a minor adjustment that was necessary to be able to produce the higher-quality paper grades.
The special machine concept of the Janus MK 2 calenders allowed the upgrade to be carried out quickly and efficiently. There was no need for major structural work in the building, as the new calender could be placed on the existing paper machine foundations thanks to the 45° incline of the roll stack, putting it on the same level as the paper machine. The inclined stack configuration also provides furtherbenefits like reduced susceptibility to vibrations, shorter roll change times and very good access.
Holmen Paper was happy with the cooperation with Voith and the paper quality as Production Manager Jenny Melander confirms: “The paper was already of a very good quality directly after startup.” The rebuild allows Holmen Paper to enhance its flexibility, because the PM 53 can switch the calender between single, double or multi-nip operating modes at any time without interrupting production, enabling it to produce paper qualities ranging from matt to glossy and from low to high density.
Holmen Paper is part of the Swedish Holmen Group and a major manufacturer of graphic papers. At mills in Braviken and Hallsta in Sweden and Madrid, Spain, it produces high-quality papers for newspapers, magazines, catalogs, advertising supplements and books.