The FennoClean concept has been designed to enable chemical usage to be tailored to application needs more efficiently, and achieve low levels of process contamination more cost-effectively. A clean process means better end-product quality and better machine productivity.

FennoClean is based on biofilm research led by Marko Kolari, Principal Scientist in Kemira’s Deposit Control team, according to Application Manager Juha Rintala, and Appli-cation Specialist Jukka Savolainen. The results of this research created the foundation for a series of new approaches to combating biofilm formation.

“Kemira has been a real pioneer in this area,” says Rintala. “The solutions offered by the FennoClean concept reduce process contamination and enhance the efficiency of paper and board ma-chines to a significant degree. Microbial slime that forms on machine surfaces, contaminate process water, can halt production, and reduce the quality of a mill’s end-product.

“Traditionally, the level of microbial con-taminants in a process – and the efficacy of a mi-crobe management program – have been moni-tored by determining the quantity of free-swim-ming bacteria in samples taken from a process. Biocide dosage has been based on this data, and been aimed at controlling this type of bacteria. Monitoring these levels does not necessarily tell the whole story about a process, however, either in terms of overall microbial contamination or the speed at which biofilm is forming.”

“In some cases, you can succeed in reduc-ing the numbers of free-swimming bacteria dramatically, thanks to what appears to be the ‘right’ biocide according to conventional wis-dom, but see the amount of problem biofilm dramatically increase,” continues Savolainen.

"Studies have shown that what are actually the ‘wrong’ biocides, or the wrong dosage, can simply increase biofilm formation.”
Thanks to Kemira’s Biofilm Formation (BF) and Hedgehog methods, it is now possible to understand why this happens.

Targeting the colonizers

Kemira has carried out research work on biofilm formation and new analytical tools for quantifying its formation for a number of years, in collaboration with the University of Helsinki and leading paper manufacturers. The main finding of this work has been that so-called colonizer or precursor bacteria play a key role in biofilm formation. These precursor bacteria are able to attach themselves to bare metal surfaces very easily, and rapidly attract other bacteria to these sites, which then become diverse microbial communities.

“When you switch your attention to combating colonizer bacteria, it’s much easier to prevent biofilm from forming in the first place, and keep processes uncontaminated by using significantly smaller quantities of chemicals. Kemira is the only company to offer the tools for identifying colonizer bacteria and the best tools for combating them,” continues Rintala.

Kemira has also developed a DNA-based method for determining whether problems in the paper that comes off a line are the result of microbial contamination.

“Understanding what is really going in biofilm formation is critical to better performance in this area. If surfaces remain clean, the quantity of free-swimming bacteria becomes more of academic interest than anything else.”

Positive experience to date

Both Rintala and Savolainen emphasize that the FennoClean concept is not just about combating slime. In addition to biofilm control chemicals, washing chemicals, treatment of incoming water, and better overall bacterial management and additive storage are also key factors.
“This all contributes to better process hygiene and cleaner products, a major plus, particularly when you’re talking about packaging board used by food manufacturers, for example. Kemira also has a number of other microbe control development projects under way.

“The BF and Hedgehog tests, which are used to select the right biocides, together with Fennosurf technology, have been used for just under two years now, and they’ve generated some excellent feedback from customers around the world. Using them has resulted in cleaner processes and reduced chemical consumption.”

Better cost efficiency

If a machine has to be stopped 24 times a year for eight-hour cleans to remove biofilm deposits, continues Rintala, this is equivalent to a total of nearly 200 hours of downtime annually. Extending the intervals between cleaning cycles by a week can reduce this to less than 130 hours a year.

“Cleaner machines and cleaner conditions for operators, together with this kind of reduced downtime, can improve a mill’s overall cost efficiency considerably,” he says.

“Of course, biofilm deposits or other similar contamination are not the only reasons machines have to be shut down. The less a machine stands idle, however, the better, in terms of production
efficiency.

“FennoClean can make an important contribution to general efforts to extend the intervals between maintenance shutdowns. And even machines that operate with four- or six-week intervals between shutdowns can benefit from a cleaner process, in terms of better-quality end-product, free of the tears and breaks caused by biofilm.

Even more important in the future

More efficient slime control and more contaminant-free processes will be even more important in the future, for at least two reasons, says Rintala.

“These types of problems are even bigger problems in closed processes, where the focus is on reducing water usage. Mills are already using 6-10 cubic meters of water per ton of paper produced,
and the trend is to cut this even further.”

Tougher statutory regulations on chemical usage are also a factor.
“Mills will have to operate with smaller amounts of chemicals than they use today in the future. It’s also probable that the use of some active
ingredients will be limited, which will only make combating microbes more difficult. When you can focus your chemical use very precisely, you get better cost efficiency with lower levels of chemical usage.”

Significant amounts have already been invested in the basic research behind the FennoClean concept – and research is continuing in areas such as improving cleaning methods and how best to use Kemira’s smart measurement and dosage technology, FennoDose, to further enhance biocide management.

This article was published in Kemira Solutions 1/2006

Back