– a project for the better utilization of spruce fibers in Europe

Download pdf - Short on the EuroFiber Project 

The general layout of the project is illustrated in figure 2 (1).

Figure 2. General layout of the EuroFiber project.

Sampling European resources of spruce

Comprehensive sampling has been carried out in the major raw material sources for the European producers of mechanical pulp: Norway spruce in Estonia, France, Norway and Sweden; Sitka spruce in Great Britain, see figure 3. For all these regions, trees with different origins and different growth conditions: from fast-grown and slow-grown stands, from young and old stands (thinning and final cutting), from more or less competitive trees within stands, from juvenile to mature wood at different heights in the trees. This sampling strategy was designed to include the major sources of variation in the most important wood and fiber properties, to create a good basis for modeling.

Figure 3. Geographic distribution of wood materials investigated in the EuroFiber project.

Measurements of wood and fiber properties

A large number of wood and fiber properties were measured for different parts of trees. This is illustrated in figure 4, showing the internal growth pattern and variations in wood and fiber properties within the stem of a spruce tree. All data were compiled and crosschecked for errors to improve the data quality (1).

Growth structure Latewood content Basic wood density Moisture content Fiber length Fiber width Fiber wall thickness Specific fiber surface area

Figure 4. Measured internal growth pattern and variations in different wood and fiber properties within the stem of an 80-year-old Norway spruce.

Modeling and simulation

From the wood and fiber data, models have been developed for property differences between parts of trees, stands and regions, see figure 5, illustrating the variation of the fiber length (cross-sectional averages) in two French spruce trees of different ages and sizes(1). The data and models have been used to identify wood materials of special interest for further investigations with respect to these properties, available volumes, harvesting practices, etc.

Figure 5. Measured (broken lines) and calculated (solid lines) data for variation along the stem of the fiber length (cross-sectional averages) for two trees from France, the small one from a first thinning, the large one from final cutting.

Extensive laboratory refining studies have also been performed on wood samples with well-defined properties and origins (2).

Pilot plant trials on selected wood types

Based on the results of data analyses and prediction models, a second sampling was carried out for comprehen­sive pilot plant trials. Chips were produced from 21 wood types of different origins. These wood types were defined to represent interesting feasible raw material selections but sampled to be somewhat more homogeneous than ordinary operational assort­ments. The origin and properties of all the sampled materials were well documented and characterized.

The pilot plant trials were performed in the facil­ities of Andritz in Springfield, Ohio, see figure 6. All the 21 wood types were refined. Some of them were also refined in mixtures and some were run at different refining intensities (3).

Properties of wood, chips, pulp, fibers and sheets were determined by Andritz, STFI-Packforsk and Norske Skog Research. The data were evaluated, and the results show very interesting differences in strength, optical and surface properties of hand-sheets as well as in energy consumption. Models were developed, showing strong relationships between wood properties and hand-sheet properties. Such correlations are illustrated in figure 7 with the use of the models for tear index and PPS (3).

Figure 7. Correlations between on the one hand virgin fiber length and basic wood density and on the other hand tear index (left plot) and Parker Print Surface, PPS (right plot). The models are based on data from pilot refining.

Mill trials

The results from the fiber measurements and the refining trials in laboratory and pilot scales were interpreted towards the backgrounds of the conditions at the participating mills. During the autumn 2002, mill trials were performed to test whether the benefits envisaged can be achieved in full-scale operation. Mill trials have been performed in four mills: The Hallsta mill of Holmen (4), the Follum and Golbey mills of Norske Skog and the Corbehem mill of Stora Enso.

Before these trials, a common general layout for the trials were designed. This was then adapted for the investigation of the most promising applications at each mill. In this way, the compilation of overall results from the trials was facilitated, while the mills still had the possibility to work on the issues of most importance to them. The overall results from the project are now compiled and reported.

Comprehensive presentations of the results from all mill trials are given in the documentation of the Eurofiber Seminar, see below.

Consistent effects on quality and costs

The results show that the properties of the wood and fiber raw material has major influences on both the product quality and the production costs in mechanical pulping and paper­making. Substantial benefits may be gained from a more selective utilization of wood and fibers. Some general conclusions from the project:

• There are large variations in wood and fiber pro­perties in the forest, within and between trees, stands and regions.
• The variations have been quantified and described with models.
• The use of chips from pulpwood, especially from thinning, may improve the optical properties of the products.
• The use of sawmill chips, especially from large-diameter timber, may improve strength properties.
• The specific energy consumption is lower for sawmill chips than for chips from pulpwood.
• The potential to benefit from a more selective wood and fiber utilization and the manner in which it should be implemented differ among mills. Practices have to be designed according to the specific demands and possibilities of the mills and companies.
• Knowledge and tools are needed for the efficient analysis of such specific demands and possibilities and for the development of dedicated applications.

These observations have been confirmed through studies on several scales: laboratory refining, pilot-plant refining trials and full-scale trials in four mills, with consistent results.

R&D in industrial project

A project like this, with interdependent activities in forests, laboratories, a pilot plant and several mills cannot be managed without a very tight interaction between all partners. A very demanding case was the planning of the pilot plant trials. Forest stands and trees were sampled in four countries at the same time by the paper companies, AFOCEL and SkogForsk. The resulting piles of logs were all sent to the Norske Skog Follum mill in Norway. All materials had to arrive in a fresh state within about a week. A sawmill was engaged to cut slabwood from the thick logs selected to provide sawmill chips. Pulpwood and sawmill chips were produced. Wood and chip samples were then taken and analyzed by Norske Skog and STFI-Packforsk. The chips were fumigated for export to the US. They were sent to Ohio, to arrive just in time for trials during the two weeks period which had been reserved. All partners were involved, showing a very high level of commitment. This is a research and development project, but it has to be run very much like an industrial project.

Active transfer of results

During the first three years, the results of the EuroFiber project were available only for the consor­tium companies. A series of project internal workshops were arranged to communicate results and to motivate persons entering the project well before new project phases were started.

The workshops, the mill trials and exchange of data and models have provided a good communication of results between the partners. Now a phase of wider dissemination of results have started. On May 5-6, 2003, a EuroFiber Seminar was arranged at STFI-Packforsk. At the seminar, the first public presentations of the results were made. During the first day, visits were arranged at STFI-Packforsk, forest operations and the Hallsta Paper Mill. During the second day results from all parts of the project were shown to the 55 participants from many countries, see figure 8. Results were presented by the project partners from characterization and modeling of wood and fiber properties, laboratory refining, pilot plant refining and the four mill trials. The comprehensive documentation from the Seminar is available on CD-ROM.

Figure 8. From the vivid communication in the cafeteria, it may be concluded that the participants enjoyed not only the seminar, but also the opportunity to meet and discuss with each other.

Four papers with results from the project formed a special session at the International Mechanical Pulping Conference 2003 in Quebec City in June, see the reference list below.

The paper mills engaged in the project are now communicating results from the project to other mills within their companies. And the research institutes STFI-Packforsk, Skogforsk and AFOCEL as well as the process supplier Andritz participating in the project are ready to support their customers in the development of applications based on the project results.

Applications prepared

The property variations are large in the forest and substantial benefits may be gained from a more selective utilization of wood and fibers. The mills are now preparing applications of the project results:

• One mill is preparing the introduction of wood selection for different products.
• The second mill will use the data and models to optimise their use of wood.
• The third mill has started to use a more favourable mix of raw materials and has simplified its wood handling.
• The fourth mill has a potential to save bleaching chemicals, but it will not proceed now.

The mills have, thus, arrived at different conclusions about if and how they can benefit from a more selective utilization of wood and fibers. Many factors have to be considered: product and process demands, available resources, logistics, costs, etc. It is therefore difficult to find the optimal solution for a mill and company. Within the EuroFiber project, the knowledge base has been improved for a more efficient utilization of wood and fiber resources. Procedures have been developed for the systematic analysis of what can be achieved in mills with different products and process demands, different wood and fiber resources and other constraints, and how it should be done.

The results of the EuroFiber project may hopefully play an important role in the development of new sound solutions for improved product quality and production efficiency in mills and companies. To achieve this, all the production chain from the tree to the product should be considered. STFI-Packforsk is most willing to further contribute to such applications.

References

1. LUNDQVIST, S.-O., EKENSTEDT, F., GRAHN, T., HEDENBERG, Ö., OLSSON, L., WILHELMSSON, L., “Selective use of European resources of spruce fibers for improved pulp and paper quality”, International Mechanical Pulping Conference. 2003. Quebec.
2. Lecourt, M., Fauchon, T., Deleuze-Brézins, C., Themelin, A., Arlinger, J., Grahn, T., Lundqvist, S.-O., Wilhelmsson, L., “Modeling TMP fiber morphology and pulp properties from wood and forest data: the example of Norway spruce”, International Mechanical Pulping Conference, Quebec (2003).
3. Fuglem, G., Sabourin, M., Lundqvist, S.-O., “Influence of spruce wood properties on thermomechanical pulping – pilot scale”, International Mechanical Pulping Conference, Quebec (2003).
4. Persson, E., Engstrand, P., Karlsson, L., Nilsson, F., Wahlgren, M., “Utilization of  natural variation in wood properties – A comparison between pilot plant and mill-scale production”, International Mechanical Pulping Conference, Quebec (2003).
   

Contact person:

Sven-Olof Lundqvist, STFI
Coordinator of the EuroFiber project

Project partners

STFI-Packforsk
SkogForsk
AFOCEL
Andritz
Norske Skog
Stora Enso
Holmen Paper
Iggesund Paperboard

The EuroFiber Seminar

On May 5-6, 2003, a EuroFiber Seminar was arranged at STFI-Packforsk. At the seminar, the first public presentations of project results were made. During the first day, visits were arranged at STFI-Packforsk, forest operations and the Hallsta Paper Mill. During the second day results from all parts of the project were shown to the 55 participants from many countries. Results were presented by the project partners from characterization and modeling of wood and fiber properties, laboratory refining, pilot plant refining and the four mill trials.

Documentation

The documentation of the EuroFiber Seminar given below is a comprehensive material based on all overhead presentations at the seminar.

The pdf files may be downloaded, on the conditions that it is accepted that the IPR of the material resides with the companies which produced and presented the material, that logotypes and references are not removed and that these companies are acknowledged on use of the material and the results involved.

• Program as pdf
  
• The industry and customer perspective on wood and fiber utilization
  (Carl Sundberg, Holmen Paper)
  
• The EuroFiber project – objectives, layout and general results
  (Sven-Olof Lundqvist, STFI-Packforsk)
  
• Samples and data on wood and fiber properties – strategies and methods
  (Lars Olsson, STFI-Packforsk)
  
• Differences in wood and fiber properties – regions, stands, trees and parts of trees Models
  (Örjan Hedenberg, STFI-Packforsk)
  
• Laboratory refining of wood with different properties – methods and results
  (Michaël Lecourt, AFOCEL)
  
• Pilot plant refining of wood with different properties – methods and results
  (Peter Bräuer, Andritz)
  
• Mill trials, validation of lab and pilot plant results. Possible application
  Introduction
  (Per Engstrand, Holmen Paper)
  Hallsta Paper Mill, Sweden
  (Erik Persson, Holmen Paper)
  Corbehem Mill, France
  (Jean Claude Cleuet, Stora Enso
  Golbey Mill, France
  (Guri Fuglem, Norske Skog)
  Follum Mill, Norway
  (Guri Fuglem, Norske Skog)
• Tools and visions
  Process applications
  (Peter Bräuer, Andritz)
  Forestry applications
  (Lars Wilhelmsson, SkogForsk)
  Tools for forest and mill integration - part 1
  Tools for forest and mill integration - part 2
  (Sven-Olof Lundqvist and Thomas Grahn, STFI-Packforsk)
  

Publications from the EuroFiber project

The EuroFiber project is in its final phase different types of material are prepared for communication of results. So far, the following public material is available:

The EuroFiber Seminar

Documentation on the web

The documentation is a comprehensive material based on all overhead presentations at the seminar.

The pdf files may be downloaded, on the conditions that it is accepted that the IPR of the material resides with the companies which produced and presented the material, that logotypes and references are not removed and that these companies are acknowledged on use of the material and the results involved.

A CD-ROM version of the documentation may be ordered from .

International Mechanical Pulping Conference 2003

At the IMPC 2003, Quebec City, June 2-5, Quebec City, Canada, a session with four papers was devoted to the EuroFiber project and its results. The papers are available in the proceedings of the conference:

1. LUNDQVIST, S.-O., EKENSTEDT, F., GRAHN, T., HEDENBERG, Ö., OLSSON, L., WILHELMSSON, L., “Selective use of European resources of spruce fibers for improved pulp and paper quality”
2. Lecourt, M., Fauchon, T., Deleuze-Brézins, C., Themelin, A., Arlinger, J., Grahn, T., Lundqvist, S.-O., Wilhelmsson, L., “Modeling TMP fiber morphology and pulp properties from wood and forest data: the example of Norway spruce”
3. Fuglem, G., Sabourin, M., Lundqvist, S.-O., “Influence of spruce wood properties on thermomechanical pulping – pilot scale”
4. Persson, E., Engstrand, P., Karlsson, L., Nilsson, F., Wahlgren, M., “Utilization of  natural variation in wood properties – A comparison between pilot plant and mill-scale production”