German corrugated sheet boards and containerboards supplier Progroup’s subsidiary Propapier has started up a Valmet-delivered, hard nip-sizing technology with related chemical systems at its PM1 Burg mill in Germany.
The OptiSizer Hard contains a pair of hardcover nip rolls on which starch is sprayed, transferred into the nip and finally sent into the paper web.
The production line PM1 is engaged in the production of liner, fluting and kraft substitutes grades based on 100% waste paper.
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.”
OptiSizer Hard reportedly offers reduced lifecycle costs and improved runnability.
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.
“It looked perfect. I couldn’t see any web tension induced wrinkling in the web. The schedule was very tight with only an 11-day shutdown time.
“The fact that we were able to squeeze it into a ten-day break was quite amazing and a proof of an excellent cooperation and preplanning.”
Valmet has replaced its existing starch preparation system at the mill with another system designed for OptiSizer Hard and its spray application method.