1. BIM Kemi AB, Box 3102, SE-443 03 Stenkullen, Sweden, Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, and Department of Microelectronics and Applied Physics, School of Information and Communication Technology, The Royal Institute of Technology, SE-100 44 Stockholm, Sweden, and STFI-Packforsk AB, Box 5604, SE-114 86 Stockholm, Sweden