1. Department of Fiber and Polymer TechnologyDivision of Fibre TechnologyKTH Royal Institute of Technology Teknikringen 56‐58 10044 Stockholm Sweden
2. Department of Fiber and Polymer TechnologyWallenberg Wood Science CenterKTH Royal Institute of Technology Teknikringen 56‐58 10044 Stockholm Sweden
3. Department of Management and EngineeringDivision of Solid MechanicsLinköping University 58183 Linköping Sweden