1. a Innventia AB, Division of Packaging, Media and Materials, P.O. Box 5604, SE-11486 Stockholm, Sweden
2. b Department of Fiber and Polymer Technology, Royal Institute of Technology, KTH, Teknikringen 56, SE-10044 Stockholm, Sweden, Innventia AB, Division of Packaging, Media and Materials, P.O. Box 5604, SE-11486 Stockholm, Sweden