German, Swiss Mills Startup New-Generation Refiners

Print this article | Send to Colleague

The first startup at the Greiz mill was on deinked pulp for trim refining/deflaking. The Greiz mill produces colored recycled papers and board for office, school, and graphics applications. The mill's target is to break fiber bundles, shives, and other impurities with minimum refining degree change. According to Ulrich Mallon, technology and quality assurance manager at Greiz, "the delivery, installation, and startup was very smooth and on schedule. Currently we are running the optimization phase, but compared with the old machine we have already observed significant energy savings."

The second OptiFiner Pro at Sappi's Biberist mill replaced four conventional conical refiners in a eucalyptus stock preparation line on a coated fine paper machine. The Biberist mill produces coated woodfree paper for the graphic arts and offset printing industry as well as woodfree uncoated pre-printed paper for office, pre-printed, and offset applications. Stefan Franke, development engineer at Sappi Biberist, says the mill's targets of energy savings and quality improvement have been met. "Energy savings are as expected with good strength development and strength improvement with the same specific refining energy," Franke noted.

The OptiFiner Pro has a very compact design. In conventional refiners, fibers travel the full length of the refining zone, suffering excessive impacts that lead to increased fines and weakening of the refined fibers. Many fibers, as much as 70% of the total, may not be treated at all. To combat this, OptiFiner Pro feeds the stock evenly across the bars directly in the refining zone where fiber treatment occurs. All of the stock is treated equally, providing higher refiner loadability and better energy efficiency. Flexibility in operation is gained as well as easier installation due to its smaller physical size.

In the photos below, the OptiFiner Pro (left) is running on deinked pulp for trim refining/deflaking at Koehler Greiz GmbH & Co. KG in Germany. The unit at Sappi Fine Paper's Biberist mill in Switzerland (right) replaced four conventional conical refiners for eucalyptus stock preparation.