Examining the wood chipping process

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The Wood and Fibre Mechanics research group is examining the wood chipping process and the possibility of tailoring this process to reduce energy consumption during subsequent refining.

Correctly modelling the wood cutting process using finite element (FE) analysis and characterizing the damage induced in wood chips during chipping are other research interests. In addition, the group is exploring the use of numerical tools (i.e., finite element analysis) in determining wood chipping process parameters, in order to optimize energy efficiency during refining. Several group members are involved in developing a measuring device for measuring (in real time) the forces acting in the gap of a mechanical refiner.

An ongoing effort of this group is part of the Extreme Papermaking project, one activity of which is modelling wet web strength and constitutive behaviour. This will help build our understanding of the fibre properties and sheet structures that control the mechanical and strength properties of wet sheets that determine stochastic strength characteristics. In the future, the group will study the thickness properties of cardboard with a special emphasis on damage evolution.

The process of casting aluminium alloys using the direct chill (DC) casting technique is being studied to improve ingot quality, in terms of improved internal structure for subsequent extrusion steps, and to minimize surface defects and inclusions. This work is being performed in close cooperation with all Swedish companies using DC casting, and is done by modelling diffusion processes, experimentally simulating solidification, and full-scale industrial trials. 

Licentiate Thesis: Helen Lusth

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Researchers in the area

Professors
Torbjörn Carlberg
Per Gradin

Researcher
Lisbeth Hellström
Staffan Nyström

Current projects

  • Increasing the energy efficiency in mechanical pulping by modifying the wood chipping process
  • Failure mechanisms in corrugated board consisting of light paper grades (PACE-project)