Cleaner paper machine, cleaner end-product, cleaner environment
Oxidizing biocides which are based on active chlorine are widely used in tissue-making for improving machine cleanliness and runnability. They provide cost-effective biocidal performance, but due to wide utilization of sodium hypochlorite many paper machines are experiencing severe corrosion issues.
FennoClean performic acid (PFA) is a halogen-free biocide program that is highly effective against primary-biofilm forming bacteria. PFA is a reaction product of formic acid and hydrogen peroxide, and its biocidal activity is based on active oxygen. PFA is thus halogen-free, corrosion safe and also fully biodegradable. This highly efficient biocide improves paper machine cleanliness while, at the same time, it does not generate any persistent AOX compounds in waste water that could be harmful for the environment. PFA also leaves no biocidal residuals in the paper product, making it safe for end users and the environment.
PiBa Assay – Targeted microbe control for optimized runnability
A total solution approach is taken for applying PFA in tissue machines. This includes a new monitoring technique PiBa Assay that allows the biocides program to be targeted more specifically at the most problematic microbes and thus optimize runnability and sustainability. PiBa Assay is a Kemira proprietary method for quantifying specific bacterial species which initiate slime formation on paper machine surfaces (Primary-biofilm formers, the real troublemakers).
Oxidizing biocide systems which have been in common use, especially the ones using ammonium and hypochlorite, have been connected to causing of metal corrosion. We tested vapor-phase corrosion tendency of three oxidizing biocide systems: PFA, ammonium sulfate+hypochlorite and ammonium bromide+hypochlorite. White water from a paper machine was treated with these three oxidizers and corrosion of the newly polished steel samples was measured. The results clearly demonstrated no corrosion caused by PFA, unlike the halogen-based oxidizing biocide technologies it was compared to.
Kemira PFA technology is currently available in Europe and Asia only.