Guest editorial
Paper is a material with many uses. It was originally developed for writing and printing upon, but is also used for packaging, cleaning, and even as a food ingredient. Paper is produced by pressing together moist fibres and then removing the water. The fibres typically come from wood or grass. The pulp and paper industry is dominated by North American, North European, and East Asian countries, but growth is expected in new economies. In 2007, 10 companies had a net sale in the range of 10–20 billion US$.
The pulp and paper industry faces several challenges. Producers in certain segments struggle with loss; for example, there has been a temporary overproduction of newsprint. Whether this problem is caused by a switch to internet news is not clear. Progress is also being made in the area of electronic books, with advances in distribution technology and electronic ink, for example, the Amazon Kindle and prototypes of colour e-ink. The potential is a purely electronic purchasing/subscription and downloading of books, magazines, and newspapers. Another challenge is the current activity in bioenergy and the resulting competition for raw materials.
To stay competitive, the industry thus needs to produce ever higher quality products at the lowest possible cost. The use of models and simulation technology is believed to be instrumental in developing and operating the modern plant. As a consequence, an action on Modelling and Simulation in the Pulp and Paper Industry was organized from 2004 to 2008 through the European Cooperation in Science and Technology (COST Action E36) with participants from 14 countries, see www.coste36.org.
Some of the work in COST E36 was disseminated through six presentations at the 5th MATHMOD Vienna conference, which took place 7–10 February 2006 at Vienna University of Technology. Updated and expanded versions of five of these presentations are presented in the sequel. The first paper by Blanco et al. gives an overview of the use of modelling and simulation in the pulp and paper industry. The second paper by Avelin et al. discusses online use of models. The third paper by Jokinen et al. discusses decision-making under uncertainty. The fourth paper by Alonso et al. treats models for predicting the final paper quality. The fifth paper by Lie considers model uncertainty.
Although the five papers presented here can only give selected snapshots of the activity in the COST E36 action, they illustrate that mathematical modelling is a key technology in the pulp and paper industry.