Search for dissertations about: "Defibration"

Showing result 1 - 5 of 10 swedish dissertations containing the word Defibration.

  1. 1. A numerical and experimental study of initial defibration of wood

    University dissertation from Structural Mechanics, Lund University

    Author : Stefan Holmberg; Lund University.; Lunds universitet.; [1998]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite element simulations; fracture; deformation; fibre; defibration; wood; Building construction; Byggnadsteknik;

    Abstract : A major drawback of the defibration or refining process in manufacturing pulp is that of its large energy requirements. If the mechanics of the process were better understood, large amounts of energy could probably be saved. The initial defibration seems to be crucial for both the quality of the pulp and the total consumption of energy. READ MORE

  2. 2. Wood and fibre mechanics related to the thermomechanical pulping process

    University dissertation from Sundsvall : Mid Sweden University

    Author : Jan-Erik Berg; Mittuniversitetet.; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustic emission; Chips; Compression tests; Defibration; Disc refiners; Energy consumption; Fibre structure; Force sensors; Fracture; Impact strength; Mathematical analysis; Moisture content; Picea abies; Refining; Stiffness degradation; Strains; Temperature; Thermomechanical pulping; Velocity; TECHNOLOGY Chemical engineering; TEKNIKVETENSKAP Kemiteknik;

    Abstract : The main objective of this thesis was to improve the understanding of some aspects on wood and fibre mechanics related to conditions in the thermomechanical pulping process. Another objective was to measure the power distribution between the rotating plates in a refiner. READ MORE

  3. 3. Manufacture of straw MDF and fibreboards

    University dissertation from Sundsvall : Kopieringen Mittuniversitetet

    Author : Sören Halvarsson; Mittuniversitetet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rice; Wheat; Straw; MDF; HDF; UF; MUF; MDI; Non-resin; binderless MDF; Ash; Silicon; SEM; Hot-pressing; MOR; MOE; IB; Thickness swelling; MDF properties; fibre swelling; WRV; Refining; Defibration.; NATURAL SCIENCES; NATURVETENSKAP; TECHNOLOGY Chemical engineering; TEKNIKVETENSKAP Kemiteknik; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik;

    Abstract : The purpose of this thesis was to develop an economical, sustainable, and environmentally friendly straw Medium Density Fibreboard (MDF) process, capable of full-scale manufacturing and to produce MDF of requested quality. The investigated straw was based on wheat (Triticum aestivum L.) and rice (Oryzae sativa L.). READ MORE

  4. 4. Modification of fluff pulp fibres: Cross-linking and alkali extraction

    University dissertation from Sundsvall : Kopieringen Mittuniversitetet

    Author : Kristoffer Lund; [2011]
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; fibre network; dry defibration; network strength; fluff pulp; Absorption; cross-linking; alkali extraction; kraft pulp;

    Abstract : Fluff pulp has been one of the key components of hygienic products, such as diapers, for many years. Fluff pulp is dry defibrated and air-laid into the absorption core of diapers. The introduction of superabsorbent polymers (SAPs) in the 1980s decreased the dependence on fluff pulp, as the SAPs became the main absorbing material. READ MORE

  5. 5. Some aspects on the effects of dissolved wood components in kraft pulping

    University dissertation from Stockholm : KTH

    Author : Ragnar Sjödahl; KTH.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Dissolved wood components; Black liquor; Defibration point; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik Cellulosa- och pappersteknik;

    Abstract : During kraft cooking a significant part of the wood material, especially lignin and hemicelluloses, is degraded and dissolved in the cooking liquor, rendering a broad range of degradation products with different molecular mass and functional groups. The main part of this thesis has been devoted to clarify the role of these dissolved wood components (DWC) during kraft cooking. READ MORE