WALLULA -- Boise Paper's new owner is investing in upgrades to two of the Wallula paper mill's three paper machines.
The machines -- called Desert Lily and Princess Sacagawea -- make release paper for labels and the brown paper that becomes the corrugated part of cardboard boxes.
The investment by Packaging Corporation of America, which bought Boise Paper in October, will improve the quality and range of the paper those machines can produce, said Sean Krajnik, mill manager. It sets the paper mill up to be sustainable during the next decade.
"This will be a pinnacle year for Wallula," he said.
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Packaging Corporation of America's papermills doubled in size after buying Boise Paper, going from four to eight paper mills, Krajnik said. The Wallula mill alone makes nearly 500,000 tons of paper and pulp in a year.
Boise Paper is a market leader in North America for the release base paper, Krajnik said. The paper is shiny on one side and dull on the other, and is the backing that other companies place labels on for bottles and other items. The company also is a large exporter of that type of paper.
The machine that makes that paper, Desert Lily, will be the first to get upgraded this spring. The rebuilt portion of that machine will be installed in June over about eight days, Krajnik said. It should be up and running that month.
Next, Princess Sacagawea, which makes the paper for the corrugated part of boxes, also called medium, will be upgraded in September. The medium is made specifically to be strong, and it resists being torn.
Boise Paper also has a machine that makes dried pulp that is rehydrated and then used by other companies to make paper. The machine is called Waii Latpu Maiden. It will be maintained, but is not getting a major upgrade like the other two, he said.
The mill was originally built in 1958, but the paper machines have been installed and updated since then, said Josh Fleming, public affairs manager. Desert Lily was first built in 1980 and had its most recent update in 2007 so it could make the release paper. It used to make envelope paper.
The paper mill operates 24 hours a day, with some shutdowns for maintenance.
It takes about 440 workers to keep the paper mill running. Of those, about 110 are dedicated to maintaining the mammoth paper machines. Desert Lily, the largest, is longer than a football field.
The company uses recycled pulp and sawdust from log mills to make paper. They also raise a cottonwood forest on about 9,000 acres just east of Burbank, with trees ready to harvest about seven years after planting, Krajnik said. The company also buys logs.
The recycled pulp is made from the small bits and pieces of cardboard left after the company's box plant next door makes cardboard boxes, he said. They also use scraps from other companies.
"We try to be as self-sufficient as we can," Krajnik said.
The paper mill has only a couple of weeks of sawdust and wood chips on hand, even though the piles seem to form a small mountain range. Supplies come in by truck and rail each day, Krajnik said.
Wood chips are pressure-cooked into a fiber. For the release paper, the fibers are bleached to change the color from brown to white, Krajnik explained. At that point, the material is 1 percent fiber, 99 percent water.
The paper machines radiate a lot of heat, turning parts of the mill into a sauna. Desert Lily and Princess Sacagawea are speedy, operating at several thousand feet per minute.
As the sheet of paper forms on the machine, water is squeezed out through very fine mesh conveyer belts that act as a screen. The holes are smaller than fibers, which are 50 microns wide.
Then the sheet is dried in what is essentially a giant oven until the paper is 95 percent fiber and 5 percent water, he said.
The plant uses 27 million gallons of water per day from the nearby Columbia River, Krajnik said. The water is then treated and returned to the river, with minimal loss.
On Desert Lily, Krajnik said they use a unique process called calendering that is sort of like being run through a wringer. A coating is applied on what will be the shiny side and the dull side of the release paper.
While technology is used to scan the paper for defects, humans also are an important part of quality control. An employee in a lab runs tests on a piece from every roll of paper the mill produces. That's a backup for the person who sits in a booth with a wall of computer screens showing the finished paper as it comes off of the machine.
Once the upgrades are finished, Krajnik said he expects less waste from defects and more flexibility in the range of release paper and medium that can be made.
-- Kristi Pihl: 582-1512; firstname.lastname@example.org