Wood Science and Technology

, Volume 35, Issue 4, pp 343–351 | Cite as

Effect of impact velocity on the fracture of wood as related to the mechanical pulping process

  • Jan-Erik Berg


 The fiber separation step in refining is crucial for energy consumption in subsequent refining where the pulp properties are developed. The size reduction of chips during refining is dependent on refining intensity and chip strength. Factors affecting these two parameters are discussed in a literature review. The impact strength of chips and the break down of chips to separate fibers are also discussed. Specifically the effect of impact velocity on the fracture of wood has been studied by use of a falling weight impact tester. Samples were prepared from a freshly cut log of Norway spruce, Picea abies, and the impact strength was measured using an instrumented falling weight impact tester. An increase in impact velocity from about 2.7 to 4.8 m/s resulted in an increase in impact strength of about 50%.


Energy Consumption Impact Strength Impact Velocity Size Reduction Picea Abies 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Jan-Erik Berg
    • 1
  1. 1.Mid Sweden University, SE-851 70 Sundsvall, Sweden Tel.: +46-60-148415; Fax: +46-60-148520 e-mail: Jan-Erik.Berg@mh.seSE

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