PaperAge Magazine

Propapier Starts-up New Hard Nip Sizer by Valmet on PM1 in Germany

Propapier PM1 at Burg mill First roll after the start-up of OptiSizer Hard on PM1 at the Propapier's Burg Mill in Germany. PM1 produces liner, fluting and kraft substitute grades from 100% recycled paper.

May 8, 2018 - Valmet announced that a new type of a sizer, OptiSizer Hard, that it delivered to Propapier's Burg mill in Germany and installed on paper machine 1 (PM1), started up successfully one day ahead of schedule on April 19.

PM1 produces liner, fluting and kraft substitute grades from 100% recycled paper.

According to Valmet, the web passed through the nip smoothly and runnability was excellent right from the start.

"The very first closing of the nip rolls is a moment telling a lot about any new sizer, especially a prototype sizer. It looked perfect. I couldn't see any web tension induced wrinkling in the web,” said Jani Hakola, Development Manager at Valmet's Board and Paper Mills Business Unit.

“The schedule was very tight with only an 11-day shutdown time. The fact that we were able to squeeze it into a 10-day break was quite amazing and a proof of an excellent cooperation and preplanning,” Hakola said.

Phillipos Vrizas, Technology Manager at Propapier, added, “I was quite amazed to see the fast start-up of our new sizer. Earlier, high web tension levels were causing quite a bit of challenges to runnability. It looks like this obstacle no longer exists. We have achieved the targeted quality specification and now we can focus on the further benefits we are aiming at e.g. steam savings, higher strength levels or starch savings.”

Valmet's delivery included the new OptiSizer Hard, which, when compared to a conventional sizer, has a pair of hard cover nip rolls. Starch is sprayed on the rolls which transfer the starch into the nip where it is further transferred into paper web.

Valmet noted that strength is among the most important benefits with OptiSizer Hard. Starch is dosed in the roll nip with higher nip pressure, which increases the density of fibers. This leads to better strength properties. To mention a few other benefits of OptiSizer Hard, the life cycle costs are lower due spray application and runnability is better due to better nip profile control.

In addition to the new sizer, an existing and outdated starch preparation system was replaced with Valmet's starch preparation system specially designed for OptiSizer Hard and its spray application method. The properties of produced starch have substantially lower range of variation, which helps to produce liner boards within the targeted quality specifications. The delivered supply system is fully automated and equipped with pressure screens, Valmet explained.

Propapier and Valmet have also established a 20-week cooperative agreement that involves finding the best practices with the new sizer such as reducing energy consumption and further improving liner and fluting properties.

Valmet is a leading global developer and supplier of process technologies, automation and services for the pulp, paper and energy industries. To learn more, please visit:

SOURCE: Valmet