Paper Machine Corrosion and Progressive Closure of the White Water System, 1996 Papermakers Conference Proceedings

Corrosion problems on paper machines are reviewed in the context of reduced water usage and progressive closure of the white water system. The paper discusses current knowledge of paper machine corrosion problems. Historical experience with the materials used for machines is reviewed and the mechanistic understanding of their corrosion performance is outlined. When net water use is reduced by lowering fresh-water input, corrodent levels can increase and previously well-specified materials may become marginally appropriate. The changes expected in white-water chemistry are detailed. Greater concentrations of critical anions like Cl - and S2 O3 -increased temperature; higher levels of dissolved and colloidal materials; residual brightening agents; and microbiological corrosion phenomena are all changes which may alter present corrosive conditions. The expected performance of paper machine components and materials is discussed in the light of such changes. It is concluded that lack of information about potential corrosion problems should not be a barrier to reduced water use and progressive closure of the white water system.