From eucalypt fiber distributions to technical properties of paper

Iiro Pulkkinen

    Research output: ThesisDoctoral ThesisCollection of Articles

    Abstract

    The objective of this thesis was to examine interfiber bonding and fiber segment activation as basic phenomena: how different raw material parameters and fiber property distributions affect bonding and activation, and in turn, how bonding and activation relate to end use properties of paper, especially to strength, structural and hygroexpansional properties. The raw materials for this study consisted of eucalypt fibers. The findings of this thesis work confirm what has already been established about bonding: raw material parameters, fiber treatments and process parameters all play a significant role in bonding and bonding development. A new observation was the interdependence of interfiber bonding and fiber network activation for structural and strength properties and the link observed between hygroexpansion and fiber network activation. Fiber size analyses were made with an optical analyzer that applies image analysis techniques on single fibers. The effects of fiber length, fiber width, fiber wall thickness, fines content and fiber curl distributions on the quality potential of eucalypt fibers were evaluated. The results of this work improved the understanding of the effects of fiber property distribution characteristics on paper technical properties. Fiber curl and fiber wall thickness were found to be the most promising fiber parameters in the evaluation of eucalypt fiber quality potential. In the development of parameters derived from fiber property distributions, the variations in paper technical properties were most often explained with fiber curl and fiber wall thickness. In addition to metafiber properties developed during this study (wet pressed density and activation parameter), more explicatory power was sought from the structure of fiber wall by means of simple water retention value and fiber saturation point measurements, differential scanning calorimetry, and by using solid-state cross-polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance measurements.
    Translated title of the contributionFrom eucalypt fiber distributions to technical properties of paper
    Original languageEnglish
    QualificationDoctor's degree
    Awarding Institution
    • Aalto University
    Supervisors/Advisors
    • Alopaeus, Ville, Supervising Professor
    • Fiskari, Juha, Thesis Advisor, External person
    Print ISBNs978-952-60-3290-0
    Electronic ISBNs978-952-60-3291-7
    Publication statusPublished - 2010
    MoE publication typeG5 Doctoral dissertation (article)

    Keywords

    • activation
    • fiber network

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