Valmet said that a new type of a sizer, OptiSizer Hard, with associated chemical systems has started up at Propapier PM1 Burg mill in Germany.

The production line PM1 is designed to produce liner, fluting and kraft substitutes grades based on 100% waste paper.

Propapier is part of Progroup, a group of companies engaged in offering products and services for the corrugated board-processing industry.

Propapier technology manager Phillipos Vrizas said: “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.”

As part of the contract awarded earlier, Valmet’s scope of delivery included OptiSizer Hard, which features a pair of hard cover nip rolls.

Valmet said: “Starch is sprayed on the rolls which transfer the starch into the nip where it is further transferred into paper web.”

Valmet Board and Paper Mills Business Unit development manager Jani Hakola said: “The very first closing of the nip rolls is a moment telling a lot about any new sizer – especially a prototype sizer.

“I couldn’t see any web tension induced wrinkling in the web. The schedule was very tight with only a 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.”

Valmet said that the OptiSizer Hard also provides reduced life cycle costs due to spray application while the runnability is improved due to better nip profile control.

The firm said it supplied Valmet’s starch preparation system designed for OptiSizer Hard and its spray application method. It has replaced the existing and outdated starch preparation system at the mill.

Progroup, which is engaged in production of containerboard and corrugated board sheets, currently operates two paper factories, a combined heat and power plant, ten corrugated board plants and several service companies.