Prolonged wood storage causes mainly brightness problems for TMP

Jari Sirviö, Airi Särkilahti, Tiina Liitiä, Antti Fredrikson, Lauri Salminen, Ilkka Nurminen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific


    During summer-time storing wood loses moisture and brightness. Storing induced wood dryness may cause problems in mechanical pulp production. Norway spruce logs were stored in piles over summer and compared to fresh wood as a raw material for TMP. The reduced wood moisture content does not require changes in thermomechanical pulping as long as the moisture content remains above the fiber saturation point. The amount of colored substances in wood increases already during the storing, and further in the refining, resulting reduced pulp brightness. This brightness loss can be mostly recovered by peroxide bleaching. However, at high brightness levels of 75-80%, the use of stored wood can increase the required peroxide charge by 8-12 kg/BDt. Combined washing and pressing treatment of the chips provides further brightness improvement.
    Original languageEnglish
    Title of host publicationProceedings of International Mechanical Pulping Conference 2011
    PublisherChinese Academy of Forestry
    ISBN (Print)978-7-5019-8251-6
    Publication statusPublished - 2011
    MoE publication typeB3 Non-refereed article in conference proceedings
    EventInternational Mechanical Pulping Conference, IMPC 2011 - Xi'an, China
    Duration: 26 Jun 201129 Jun 2011


    ConferenceInternational Mechanical Pulping Conference, IMPC 2011
    Abbreviated titleIMPC 2011


    • thermomechanical pulp
    • wood storage
    • brightness
    • bleaching
    • chip pretreatment


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