UPM Kajaani mill is a key supplier to the Japanese manga comic industry. A new process water solution has helped improve quality
January 2008
By Martin Koepenick
Anyone who runs a paper machine at 1,400/m/min knows that breaks come with the territory. Any means of minimizing them is taken seriously.
"To reduce breaks on our PM 4 newsprint machine, we decided to break with tradition," explains production manager at UPM Kajaani mill in Finland, Kalle Luomi. "Instead of using organic biocides in the process water, we switched to chlorine dioxide (ClO2), produced by a small on-site generator. Our hunch about purifying process water, and minimizing organic biocides is paying off."
Luomi and his team have a near obsession with quality, not only because Finland has a high standard for papermaking, but because of the demands of some rather unique customers.
Nothing funny about manga success
For close to two decades Kajaani's PM 3 and PM 4 have won the business to supply special newsprint papers to Japan for 'manga' comic strips and books – a distinctive and highly popular part of the country's culture.
Japanese printers, who produce billions of manga publications each year, have a low tolerance for imperfections in the sheet, especially the number of holes. In addition to a high quality standard, and intolerance for imperfections, opacity, bulk, stiffness and tint are the key properties.
In addition, they are determined to minimize breaks on the printing presses. "At Kajaani we are committed to continuous improvement, always trying to find ways to improve our grades. All of our customers benefit from what we do for the Japanese market. We are pushed hard, so push ourselves even more," says Luomi.
"The Japanese customer is undoubtedly the world's most demanding," believes technical customer service manager, UPM Kajaani, Timo Palo. "There is zero tolerance for any quality imperfections. Their Kaizen philosophy advocates continuous improvement in a person's professional and personal life. We have gained by adopting the Kaizen way ourselves. And it's a good fit for Finland."
Runnability
"When our team took on the challenge to continuously reduce breaks and improve quality, water purification was a novel idea that made sense," says Luomi. "When you think about it, water is the transfer media - 99% of what runs through the machines - so it affects runnability and the end product in many ways" he notes.
UPM Kajaani paper machine superintendent Lasse Kauppinen was an early advocate of alternatives to organic biocides. "We wanted to find the most cost efficient biocide program from various alternatives," he recalls.
According to Kauppinen, the majority of the breaks were dirty breaks. "We have web cameras to capture the origins of problems. What starts as a miniscule problem in the web - like slime, deposits or stickies - leads to breaks. We already knew that after process washing, breaks decreased. We also knew that dirt in the pipelines and tanks contributed to the problem. And that organic biocide treatment did not work well enough. This made chlorine dioxide from Eka Chemicals produced with Eka Purate an interesting technology to consider," he explains.
"Runnability went in a better direction right from the start," says Luomi. "We did encounter a few glitches as we tried to further optimize. But that's normal. In papermaking, optimization often means rocking the boat! But that's okay if you can handle the short term issues."
Dropping the proven approach
Traditional biocides, such as glutaraldehyde and DBNPA (bromide chemistry base) have been the industry standard. These chemistries didn't prevent slime and deposit build up in various places on the paper machine and the web itself. Running clean rarely happened.
According to Eka, the production of chlorine dioxide using Purate produces the lowest chloride content of any ClO2 method. The chloride produced is the natural consequence of the oxidation reaction of any ClO2 through to the final chloride. For every mg of reacted ClO2 about ½ mg of chloride is formed. The company Savcor was retained to measure the impact of the new "non-chloride-addition" system by balancing ionic levels around the operating areas and in the carry-over to the waste treatment plant. "Data tell us that there is no corrosion concern or carryover. This is important, because we are, in fact, running clean, and, in addition, the good bacteria in waste treatment are not adversely affected at all. No additional chloride ions in the process and no carryover are key benefits, and proof of the viability of this approach," believes Luomi.
"Once our new chlorine dioxide system was in place instead of traditional biocides, breaks dropped, and quality rose. All of us knew that we were doing the right things, based on our willingness to look at the process a little differently," he concludes.
|
|
|
The word 'manga' can be traced to Katsushika Hokusai – a Japanese artist who lived during the late 1700s and early 1800s – who drew the word in question on his playful black-and-white sketches. A literal translation of manga means 'random pictures'.
In Japan manga is simultaneously ambitious art and successful industrial mass production. Almost 40% of the printed products published in Japan are manga. The annual number of manga comics published approaches the impressive figure of 2.3 billion issues.
Manga attracts readers of all ages and offers countless genres, from romance to sports and sci-fi. "Manga is easy to read and carry around," says sales manager, UPM Tokyo, Ian Hamilton, when explaining the comic strips' popularity. "Currently we supply papers to two Japanese publishers. Through them our products find their way into the hands of millions in publications such as Young Magazine, Weekly Shonen Magazine and Big Comic Spirits. "Generally local publishers never rely on only one supplier," continues Hamilton. "In the mangas this can be clearly seen in the differently-colored newsprint papers used in publications that are almost as thick as telephone directories."
|
Additional material from UPM customer magazine, The Griffin
Pulp & Paper International is FREE to qualified subscribers.
Click here to find out more.
