Sunday, October 26, 2008

Better housekeeping for paper machines.

There has been definitely some improvement in the microbiological control of paper machines since late 1970's (when IM started his work for it). As a very short review, two issues have been highlighted because their positive effect on the hygiene and driveability of machines: application of oxidative agents as biocides and biofilm research. Rapid killing of microbes in strategic sites of processes with compounds like peracetic acid, chlorine dioxide and ozone have given very promising results when the overall load of microbes inside machines shall be dropped. Better understanding of the features of biofilms - essential changes of bacterial metabolism when they attach on surfaces from flowing water and start to release more and more living cells and spores back to the process  - also help to focus attention on them.

Poor interests to invest in better analytical control of microbial activities, in opposite, is surprising, however. Why do the mills not benefit the obvious progress of such control methods like ON LINE luminometry, rapid PMEU incubations etc.? Is it a question of lacking knowledge, lacking interest or the status of old-fashioned analytical methods, not suited to rapid QC/HACCP of paper and board processes? Is microbiology regarded as the unknown living creature on the surface of "Solaris" in the novel of S.Lem (the most excellent film by Andrei Tarkovsky recommended!)

IM has been relatively frustrated for this situation but tries to think optimistic: some small-scale simulations are already running today, and more and more people with technical background have been interested to know about tools to estimate and forecast microbiological events inside their machines. Happy to hear that they understand that with costs of only a couple machine rolls they could have improved microbiological control which can lead to remarkable spare of money when preventing unexpected machine stops or claims of poor product quality by customers.