1. Department of Physics, Chalmers University of Technology, Gothenburg 412 96, Sweden
2. FibRe-Centre for Lignocellulose-based Thermoplastics, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
3. Tetra Pak, Lund 221 86, Sweden
4. Paul Scherrer Institute, Villigen 5232, Switzerland
5. Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland