Holmen Hallsta monitors whitewater consistency as a means to evaluate process stability, and make adjustments as needed. Because it produces such a wide range of grades, where brightness, filler content and basis weight vary, it needs to fine tune all the time, especially after grade changes.
The hallmarks of Holmen Hallsta grades include: clean, smooth surface; good stiffness; and, a wide range of choices in bulk, grammage, brightness and shade
One method employed to stabilize the wet end was the installation of a control loop to regulate consistency. This gave the mill a means to achieve cleaner whitewater and better retention. Next, it decided to test a new retention system. The first step in April 2010 was to employ a polymer to lower the level of variation. Andersson adds, "Our goal was to make life easier making frequent changes. The polymer alone delivered better white water consistency, and allowed faster grade changes."
The next step of the trial focused on the silica nanoparticle component, applied at several key locations.
Andersson explains, "Soon, we met and then exceeded retention targets, and saw gains in drainage. We have run smoother ever since, and profited also from know-how and close attention via the EPI (Eka Processes Intelligence) monitoring of retention chemicals."
Because there are 30 different recipes for grades, including different types of fillers and a range of chemicals, Holmen Hallsta considers retention as an essential tool for stability. Mats Harzdorf, PM 12 technician, says, "Cleaner whitewater confirms better retention on the machine. Employing chemistry that delivers greater control allows us to push further with quality and efficiency."
Holmen Hallsta’s production manager, Per Arne Andersson says, “Stability at the wet end correlates closely with customer satisfaction. Thrillers like Giorgio Fallati’s ‘lo sono dio’ gain an extra touch for the reader from our book papers”
Andersson and team value thoughtful input from the outside. "We need a strategic partner to handle our questions, and to discuss developments. When there is a problem, we need experts to help us explore issues in our system. Operators want smart options to address particular problems."
As at many mills, downsizing means that outside expertise is critical. Harzdorf continues, "Good retention is extremely important for runnability. You have to prepare carefully for making any changes, and especially something as bold as what we did with the implementation of our particular retention system. Discussions were productive and ongoing. Lab trials and evaluations were done frequently. We are always seeking a combination of saving money and running better. In this case, the result was an improvement in our products, and cost efficiency."
What Eka refers to as its EPI allows it to observe, monitor and adjust chemical dosages when away from the mill. This "remote" set of eyes actually connects experts to the PM 12 process 24 hours per day. Says Mikael Kvistblom, AkzoNobel-Eka Chemicals, project manager retention, "Last weekend I received an alert on my mobile phone that a pump stopped. I contacted the operators, and helped them bring it back up on line, and deliver the chemicals as before."
Andersson adds, "Eka's EPI gives us another kind of hands on support. When you have a system that works like ours, there are a lot of considerations to maintain excellent runnability."
According to Kvistblom, "EPI is a good way to be closer to the team at Holmen Hallsta, and be better prepared when we meet, or review our own systems at the mill. We can both act faster to make corrections. In the end, success with advanced chemistry always comes from applying knowledge to a specific machine and grades, giving the mill team the comfort that stability brings."
Rebecka Andersson, senior application engineer with Eka Chemicals, notes. "EPI is a timesaver, and a tool that enables Eka to be proactive. We work with the Hallsta team constantly to drive performance higher. We explain a lot to operators about the effects of chemistry. When they know more, they can apply that knowledge, and see for themselves what a particular adjustment does.
"It would be impossible without EPI to run the trial with such a high degree of "hands on" attention. Even if we had someone living next to the paper machine, it would not compare to what we can now achieve. EPI reaches into the system every five minutes, and sends an alarm or alert if something is not as it should be. We can adapt dosages ourselves from anywhere, and we are able to inform operators of something they need to address, day or night."
Kindle: A complement
|Both Wiksand and Andersson, suggest that Kindle is a complement to books today. Studies suggest that reading books is growing in Scandinavia and Europe.
Says Andersson, “If I compare my childhood to my own kids, they are reading a lot of books. This is a good trend for our society. It’s popular to read books in Sweden and in Europe. That’s our life line. To shift from books, especially pocketbooks, to an electronic pad will take a long time, and most likely, a balance of the two will remain the norm. However, it’s clear that e-books have affected the market in the US.”
Says Wiksand, “When it comes to novels, we are maintaining our position. The school book market is changing. As for Kindle, it’s hard to predict how much it will grow. Kindle, even with its shortcomings, is a good tool. But it’s expensive; we consider the iPad to be another market.
“I believe that book paper has a bright future. Holmen Paper recently attended World Book Night in London, where we were a sponsor. This event is about the promotion of reading. Many powerful players in the book industry gave assurances of a long, fruitful continuation of books on paper.”