Effects of electrolytes, pH and surface tension on dewatering, dry and wet web properties

Hanna Lindqvist, K. Salminen, J. Kataja-aho, Anna Sundberg, Bjarne Holmbom, E. Retulainen

    Research output: Contribution to journalArticleScientificpeer-review

    9 Citations (Scopus)

    Abstract

    Speed of paper machines is often limited by the drainage rate of the furnish and the mechanical properties of the wet web, i.e. the tension and relaxation properties. The conductivity of the water was adjusted to 1 mS/cm with CaCl2 and the pH was 6.5 in order to mimic conditions on a fine paper machine. Addition of a non-ionic surfactant at concentrations below critical micelle concentration (cmc) decreased dewatering time and increased dry content. Tensile strength and residual tension at 2% strain of the wet web increased until cmc, primarily due to the increased dry content after wet pressing. Density, air permeability and tensile strength increased for dry sheets. Lowering of pH from 6.5 to 5, decreased dry content after wet pressing and air permeability of dry sheets. Adjustment of conductivity with NaCl caused a decrease in both tensile strength and residual tension for wet sheets and increased dewatering time.
    Original languageUndefined/Unknown
    Pages (from-to)148–154
    JournalJournal of Pulp and Paper Science
    Volume35
    Issue number3-4
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed

    Keywords

    • Surface tension
    • pH
    • electrolytes
    • conductivity
    • Papermaking
    • Wet web strength
    • runnability
    • Non-ionic surfactant

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