High yield pulping technology

Research focused on raw material, process technology and new or improved products and qualities.

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High yield pulp (HYP) is produced at a yield over 85% from different pulpwoods or annual plants by means of mechanical or combined chemical and mechanical unit processes. The research area is of high industrial importance. All Swedish and Norwegian forest industry companies producing high yield pulps, the world’s primary machine suppliers as well as a number of chemical suppliers are all cooperating together with the HYP research group within FSCN in several projects.

We believe high yield pulps to be a future key material in sustainable products and our mission is to potentiate an increased usage of high yield pulps, even though the demand for newsprint paper grades is drastically decreasing. The research is focused on our primary goals, i.e., helping our industry partners to a new and improved level of knowledge with regard to process efficiency and product development. In order to succeed, we work in a multidisciplinary way engaging university researchers and industry experts in areas ranging from wood and fibre chemistry, paper technology, chemical and mechanical engineering to material physics and control engineering.

The research covers different topics such as wood chipping, mechanical and chemical pre-treatments, high and low consistency refining, bleaching, and further development of nano-scale fibrils. Most of the projects and activities can be categorized into three fields:

Raw material

Understanding the properties of the wood matrix and wood polymers is important already in the chipping process where energy efficiency in the following refining stages can be improved if the chipping process is optimized. Similarly, knowledge of how wood polymers can be softened and swelled by thermal, mechanical and chemical pre-treatments under relevant process conditions is needed to be able to drastically improve process efficiency in refining.

Process technology

Chip refining is responsible for more than 60% of the electric energy consumption in most HYP processes. Increasing refining efficiency is therefore crucial. Examples of projects in this area are focusing on refiner stability and control, replacing part of the high consistency refining by low consistency refining, pre-treatment in combination with intensified refining and developing radically new segment designs for small refiner gaps.

New or improved products and qualities

To make it possible to replace low yield bleached chemical pulps in various products it is essential to reach higher brightness maxima and reduce chemical costs in HYP bleaching. In order to enable a broader use of pulps produced with known low energy refining techniques we also study new combinations of multilayer techniques that can improve the strength properties of the final product. Moreover we are studying the possibilities of rejecting fibre and fines materials detrimental to final product properties from the main line enhancing product quality. The possibilities of utilizing these rejects for more unconventional new purposes are studied in parallel.

Researchers in the area

Professors
Per Engstrand
Per Gradin
Thomas Granfeldt, Adjunct Professor
Magnus Paulsson, Adjunct Professor
Lennart Salmén, Adjunct Professor

Researchers
Olof Björkqvist
Jan-Erik Berg
Birgitta Engberg
Olof Ferritsius
Rita Ferritsius
Sven Norgren
Johan Persson
Gunilla Pettersson
Staffan Nyström
Christer Sandberg

Research projects

EcoMat

EcoSys

e2cmp

FORIC

ModDD

Segment

Publications

Articles in journals
Articles, reviews/surveys
Books
Chapters in books
Conference papers
Doctoral theses, comprehensive summaries
Licentiate theses, comprehensive summaries
Licentiate theses, monographs
Manuscripts
Patents
Reports

Articles in journals

Cordova, A. , Afewerki, S. , Alimohammadzadeh, R. , Sanhueza, I. , Tai, C. , Osong, S. H. , Engstrand, P. & Ibrahem, I. (2019). A sustainable strategy for production and functionalization of nanocelluloses. Pure and Applied Chemistry, vol. 91: 5, pp. 865-874.  

Norgren, R. , Jonsson, A. & Björkqvist, O. (2019). Bio-sludge from the pulp and paper industry as feed for black soldier fly larvae : A study of critical factors for growth and survival. Waste and Biomass Valorization,    

Alimohammadzadeh, R. , Osong, S. H. , Abbaszad Rafi, A. , Dahlström, C. & Cordova, A. (2019). Cellulosic Materials: Sustainable Surface Engineering of Lignocellulose and Cellulose by Synergistic Combination of Metal-Free Catalysis and Polyelectrolyte Complexes. Global Challenges, vol. 3: 7  

Sandberg, C. , Berg, J. & Engstrand, P. (2019). Low Consistency Refining Combined with Screen Fractionation : Reduction of Mechanical Pulping Process Complexity. BioResources, vol. 14: 1, pp. 882-894.    

Alimohammadzadeh, R. , Osong, S. H. , Abbaszad Rafi, A. , Dahlström, C. & Cordova, A. (2019). Sustainable Surface Engineering of Lignocellulose and Cellulose by Synergistic Combination of Metal‐Free Catalysis and Polyelectrolyte Complexes. Global Challenges, vol. 3    

Nyström, J. , Gradin, P. & Thörnberg, B. (2018). An experimental study of the chipping process with focus on energy consumption and chipping angles. Nordic Pulp & Paper Research Journal, vol. 33: 3, pp. 460-467.  

Ferritsius, O. , Ferritsius, R. & Rundlof, M. (2018). Average fibre length as a measure of the amount of long fibres in mechanical pulps - ranking of pulps may shift. Nordic Pulp & Paper Research Journal, vol. 33: 3, pp. 468-481.  

Rahman, H. , Engstrand, P. , Sandström, P. & Sjöstrand, B. (2018). Dewatering properties of low grammage handsheets softwood kraft pulps modified to minimize the need for refining. Nordic Pulp & Paper Research Journal, vol. 33: 3, pp. 397-403.  

Sandberg, C. , Nelsson, E. , Engberg, B. A. , Berg, J. & Engstrand, P. (2018). Effects of chip pretreatment and feeding segments on specific energy and pulp quality in TMP production. Nordic Pulp & Paper Research Journal, vol. 33: 3, pp. 448-459.  

Norgren, S. , Pettersson, G. & Höglund, H. (2018). Strong paper from spruce CTMP - Part II : Effect of pressing at nip press temperatures above the lignin softening temperature. Nordic Pulp & Paper Research Journal, vol. 33: 1, pp. 142-149.    

Ferritsius, R. , Ferritsius, O. , Hill, J. , Karlström, A. & Eriksson, K. (2018). TMP properties and refiner conditions in a CD82 chip refiner at different operation points. Part II : Comparison of the five tests. Nordic Pulp & Paper Research Journal, vol. 33: 1, pp. 82-94.  

Ferritsius, R. , Ferritsius, O. , Hill, J. , Karlström, A. & Eriksson, K. (2018). TMP properties and refining conditions in a CD82 chip refiner. Part I : Step changes of process variables, description of the tests. Nordic Pulp & Paper Research Journal, vol. 33: 1, pp. 69-81.  

Moilanen, C. , Björkqvist, T. , Ovaska, M. , Koivisto, J. , Miksic, A. , Engberg, B. A. , Salminen, L. I. , Saarenrinne, P. & et al. (2017). Influence of strain rate, temperature and fatigue on the radial compression behaviour of Norway spruce. Holzforschung, vol. 71: 6, pp. 505-514.  

Sandberg, C. , Berg, J. & Engstrand, P. (2017). Low consistency refining of mechanical pulp - system design. TAPPI Journal, vol. 16: 7, pp. 419-429.

Nelsson, E. , Paulsson, M. , Sandberg, C. , Svensson-Rundlöf, E. & Engstrand, P. (2017). Low dosage sulfite pretreatment at different refining temperatures in mill scale TMP production. Nordic Pulp & Paper Research Journal, vol. 32: 1, pp. 59-69.    

Sandberg, C. , Berg, J. & Engstrand, P. (2017). Mill evaluation of an intensified mechanical pulping process. Nordic Pulp & Paper Research Journal, vol. 32: 2, pp. 204-210.    

Ferritsius, O. , Ferritsius, R. , Hill, J. , Karlström, A. , Ferritsius, J. & Eriksson, K. (2017). Process considerations and its demands on TMP property measurements - A study on tensile index. Nordic Pulp & Paper Research Journal, vol. 32: 1, pp. 45-53.  

Sandberg, C. , Berg, J. & Engstrand, P. (2017). Process intensification in mechanical pulping. Nordic Pulp & Paper Research Journal, vol. 32: 4, pp. 615-622.    

Pettersson, G. , Norgren, S. & Höglund, H. (2017). Strong paper from spruce CTMP - Part I. Nordic Pulp & Paper Research Journal, vol. 32: 1, pp. 54-58.  

Afewerki, S. , Alimohammadzadeh, R. , Osong, S. H. , Tai, C. , Engstrand, P. & Cordova, A. (2017). Sustainable Design for the Direct Fabrication and Highly Versatile Functionalization of Nanocelluloses. Global Challenges, vol. 1: 7    

Rahman, H. , Lindström, M. E. , Sandström, P. , Salmen, L. & Engstrand, P. (2017). The effect of increased pulp yield using additives in the softwood kraft cook on the physical properties of low-grammage handsheets. Nordic Pulp & Paper Research Journal, vol. 32: 3, pp. 317-323.    

Hellström, P. , Heijnesson-Hulten, A. , Paulsson, M. , Hakansson, H. & Germgard, U. (2016). A comparative study of enzymatic and Fenton pretreatment applied to a birch kraft pulp used for MFC production in a pilot scale high-pressure homogenizer. TAPPI Journal, vol. 15: 6, pp. 375-381.

Moilanen, C. S. , Björkqvist, T. , Engberg, B. A. , Salminen, L. I. & Saarenrinne, P. (2016). High strain rate radial compression of Norway spruce earlywood and latewood. Cellulose (London), vol. 23: 1, pp. 873-889.  

Gradin, P. , Berg, J. & Nyström, S. (2016). Measuring Tangential Forces in a Pulp Refiner : A Novel Approach. Experimental techniques (Westport, Conn.), vol. 40: 2, pp. 789-793.  

Osong, S. H. , Dahlström, C. , Forsberg, S. , Andres, B. , Engstrand, P. , Norgren, S. & Engström, A. (2016). Nanofibrillated cellulose/nanographite composite films. Cellulose (London), vol. 23: 4, pp. 2487-2500.  

Marais, A. , Enarsson, L. , Pettersson, G. , Lindström, T. & Wågberg, L. (2016). Pilot-scale papermaking using Layer-by-Layer treated fibres; Comparison between the effects of beating and of sequential addition of polymeric additives. Nordic Pulp & Paper Research Journal, vol. 31: 2, pp. 308-314.

Karlström, A. , Hill, J. , Ferritsius, R. & Ferritsius, O. (2016). Pulp property development Part II : Process non-linearities and their influence on pulp property development. Nordic Pulp & Paper Research Journal, vol. 31: 2, pp. 287-299.

Karlström, A. , Hill, J. , Ferritsius, O. & Ferritsius, R. (2016). Pulp property development Part III : Fiber residence time and consistency profile impact on specific energy and pulp properties. Nordic Pulp & Paper Research Journal, vol. 31: 2, pp. 300-307.

Osong, S. H. , Norgren, S. , Engstrand, P. , Lundberg, M. , Reza, M. & Tapani, V. (2016). Qualitative evaluation of microfibrillated cellulose usingthe crill method and some aspects of microscopy. Cellulose (London), vol. 23: 6, pp. 3611-3624.    

Reyier Österling, S. , Ferritsius, O. , Ferritsius, R. , Johansson, C. & Stångmyr, J. (2016). Weighted averages and distributions of fibre characteristics of mechanical pulps – Part II: Distributions of measured and predicted fibre characteristics by using raw data from an optical fibre analyser. Appita journal, vol. 69: 1, pp. 64-73.

Göransson, K. , Söderlind, U. , Engstrand, P. & Zhang, W. (2015). An experimental study on catalytic bed materials in a biomass dual fluidised bed gasifier. Renewable energy, vol. 81, pp. 251-261.  

Zhang, W. , He, J. , Engstrand, P. & Björkqvist, O. (2015). Economic evaluation on bio-synthetic natural gas production integrated in a thermomechanical pulp mill. Energies, vol. 8: 11, pp. 12795-12809.    

Sandberg, C. & Berg, J. (2015). Effect of flow recirculation on pulp quality and energy efficiency in low consistency refining of mechanical pulp. Nordic Pulp & Paper Research Journal, vol. 30: 2, pp. 230-233.  

Moilanen, C. S. , Saarenrinne, P. , Engberg, B. A. & Björkqvist, T. (2015). Image-based stress and strain measurement of wood in the split-Hopkinson pressure bar. Measurement science and technology, vol. 26: 8  

Göransson, K. , Söderlind, U. , Henschel, T. , Engstrand, P. & Zhang, W. (2015). Internal tar/CH4 reforming in a biomass dual fluidised bed gasifier.. Biomass Conversion and Biorefinery, vol. 5, pp. 355-366.  

Nelsson, E. , Sandberg, C. , Svensson-Rundlöf, E. , Engstrand, P. , Fernando, D. & Daniel, G. (2015). Low dosage sulfite pretreatment in a modern TMP-line. Nordic Pulp & Paper Research Journal, vol. 30: 4, pp. 591-598.    

Berg, J. , Sandberg, C. , Engberg, B. A. & Engstrand, P. (2015). Low-consistency refining of mechanical pulp in the light of forces on fibres. Nordic Pulp & Paper Research Journal, vol. 30: 2, pp. 225-229.    

Karlström, A. , Hill, J. , Ferritsius, R. & Ferritsius, O. (2015). Pulp property development Part I: Interlacing under-sampled pulp properties and TMP process data using piece-wise linear functions. Nordic Pulp & Paper Research Journal, vol. 30: 4, pp. 599-608.    

Pettersson, G. , Höglund, H. , Norgren, S. , Sjöberg, J. , Peng, F. , Hallgren, H. , Moberg, A. , Ljungqvist, C. & et al. (2015). Strong and bulky paperboard sheets from surface modified CTMP, manufactured at low energy. Nordic Pulp & Paper Research Journal, vol. 30: 2, pp. 318-324.  

Reyier Österling, S. , Ferritsius, O. , Ferritsius, R. & Stångmyr, J. (2015). Weighted averages and distributions of fibre characteristics of mechanical pulps Part I : Various methods of weighting data from an optical analyser can give averages that rank pulps differently. Appita journal, vol. 68: 4, pp. 357-368.

Hellström, L. M. , Biller, S. , Edvardsson, S. & Gradin, P. A. (2014). A theoretical and experimental study of the circular sawing process. Holzforschung, vol. 68: 3, pp. 307-312.  

Walter, K. , Paulsson, M. & Engstrand, P. (2014). Acid Hydrogen Peroxide Treatment of Norway Spruce TMP : The Effect of an Extended pH Range when Catalyzed by Free Ferrous and Free or EDG/EDTA-Chelated Ferric Ions. Journal of wood chemistry and technology, vol. 34: 2, pp. 135-155.  

Norgren, S. & Hoglund, H. (2014). Consolidation of fibre-fibre bonds in TMP and CTMP based papers. Paper Technology, vol. 55: 3, pp. 6-10.

Osong, S. H. , Norgren, S. , Engstrand, P. , Lundberg, M. & Hansen, P. (2014). Crill : A novel technique to characterize nano-ligno-cellulose. Nordic Pulp & Paper Research Journal, vol. 29: 2, pp. 190-194.  

Hellström, P. , Heijnesson-Hultén, A. , Paulsson, M. , Håkansson, H. & Germgård, U. (2014). Fenton pre-treated microfibrillated cellulose evaluated as a strength enhancer in the middle ply of paperboard. Nordic Pulp & Paper Research Journal, vol. 29: 4, pp. 732-740.  

Osong, S. H. , Norgren, S. & Engstrand, P. (2014). Paper strength improvement by inclusion of nano-ligno-cellulose to Chemi-thermomechanical pulp. Nordic Pulp & Paper Research Journal, vol. 29: 2, pp. 309-316.  

Enberg, S. , Rundlöf, M. , Paulsson, M. , Axelsson, P. , Eriksen, O. & Engstrand, P. (2014). Some causes of formation of colour during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp. Nordic Pulp & Paper Research Journal, vol. 29: 2, pp. 356-366.  

Karlsson, A. , Paulsson, M. , Engstrand, P. & Hedenström, E. (2014). Strategies to reduce heat-induced darkening for enhanced bleachability of mechanical pulps. Appita journal, vol. 67: 1, pp. 50-57.

Hellström, P. , Heijnesson-Hultén, A. , Paulsson, M. , Håkansson, H. & Germgård, U. (2014). The effect of Fenton chemistry on the properties of microfibrillated cellulose. Cellulose (London), vol. 21: 3, pp. 1489-1503.  

Enberg, S. , Rundlöf, M. , Paulsson, M. , Axelsson, P. , Eriksen, O. & Engstrand, P. (2014). The influence of process waters on optical properties during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp. Nordic Pulp & Paper Research Journal, vol. 29: 2, pp. 344-355.    

Isaksson, P. , Gradin, P. A. & Hellström, L. M. (2013). A numerical and experimental study regarding the influence of some process parameters on the damage state in wood chips. Holzforschung, vol. 67: 6, pp. 691-696.  

Lusth, H. , Gradin, P. A. & Hellström, L. M. (2013). A theoretical model for the prediction of energy consumption during the chipper canter process. Nordic Pulp & Paper Research Journal, vol. 28: 2, pp. 211-215.  

Walter, K. , Paulsson, M. & Hellström, P. (2013). Acid hydrogen peroxide treatment of Norway Spruce TMP : A model study using free ferrous ions and ferric ions chelated with EDTA as catalysts. Journal of wood chemistry and technology, vol. 33: 4, pp. 267-285.  

Osong, S. H. , Norgren, S. & Engstrand, P. (2013). An approach to produce nano-ligno-cellulose from mechanical pulp fine materials. Nordic Pulp & Paper Research Journal, vol. 28: 4, pp. 472-479.      

Ragauskas, A. J. , Paulsson, M. & Goyal, G. (2013). Editorial perspective on bleaching : Today and tomorrow. TAPPI Journal, vol. 12: 10, pp. 5-6.

Fjellström, H. , Engstrand, P. & Htun, M. (2013). ON THE RELATIONSHIP BETWEEN WOOD FIBRE WALL SWELLING, CHARGED GROUPS, AND DELAMINATION DURING REFINING. J-FOR-JOURNAL OF SCIENCE & TECHNOLOGY FOR FOREST PRODUCTS AND PROCESSES, vol. 3: 4, pp. 30-34.  

Fjellström, H. , Engstrand, P. & Htun, M. (2013). On the relationship between wood fibre wall swelling, charged groups, and delamination during refining. Journal of Science & Technology for Forest Products and Processes, vol. 3: 4, pp. 30-34.

He, J. , Engstrand, P. , Björkqvist, O. & Zhang, W. (2013). Techno-economic evaluation of a mechanical pulp mill with gasification. Nordic Pulp & Paper Research Journal, vol. 28: 3, pp. 349-357.  

Enberg, S. , Rundlöf, M. , Paulsson, M. , Johnsen, I. A. & Axelsson, P. (2013). The influence of process conditions during pulp storage on the optical properties of Norway spruce mechanical pulps. Nordic Pulp & Paper Research Journal, vol. 28: 2, pp. 203-210.  

Edvardsson, S. , Gradin, P. , Isaksson, P. & Gulliksson, M. (2012). A Note on Wet Paper Web Adhesion Strength. Journal of Testing and Evaluation, vol. 40: 4, pp. 682-686.  

Andersson, S. , Sandberg, C. & Engstrand, P. (2012). Comparison of mechanical pulps from two stage HC single disc and HC double disc - LC refining. Appita journal, vol. 65: 1, pp. 57-62.

Karlsson, A. , Enberg, S. , Rundlöf, M. , Paulsson, M. & Edström, P. (2012). Determining optical properties of mechanical pulps : Sheetmaking procedure and investigation of different ways to evaluate light absorption. Nordic Pulp & Paper Research Journal, vol. 27: 3, pp. 531-541.    

Ferritsius, R. , Reyier Österling, S. & Ferritsius, O. (2012). Development of TMP fibers in LC- and HC-refining. Nordic Pulp & Paper Research Journal, vol. 27: 5, pp. 860-871.  

Andersson, S. , Sandberg, C. & Engstrand, P. (2012). Effect of long fibre concentration on low consistency refining of mechanical pulp. Nordic Pulp & Paper Research Journal, vol. 27: 4, pp. 702-706.    

Hellström, L. , Carlberg, T. , Engstrand, P. , Gradin, P. & Gregersen, Ø. (2012). Evaluation Of Collimated Chipping Technology For Reducing Energy Consumption In Mechanical Pulping. Journal of Science & Technology for Forest Products and Processes, vol. 2: 3, pp. 6-9.

Hafrén, J. , Nelsson, E. , Gerritsen, H. C. & Bader, A. N. (2012). Optical properties of thermomechanical pulp (TMP) obtained from sulfite-pretreated Norway spruce with focus on two-photon spectral imaging (TPSI). Holzforschung, vol. 66: 7, pp. 817-824.  

Nelsson, E. , Sandberg, C. , Hildén, L. & Daniel, G. (2012). Pressurised compressive chip pre-treatment of Norway spruce with a mill scale Impressafiner. Nordic Pulp & Paper Research Journal, vol. 27: 1, pp. 056-062.  

Gorski, D. , Johansson, L. & Engstrand, P. (2012). Refiner bleaching in a peroxide-based ATMP process compared with conventional bleaching. Holzforschung, vol. 66: 3, pp. 275-281.  

Salmi, A. , Salminen, L. I. , Engberg, B. A. , Bjorkqvist, T. & Haeggstrom, E. (2012). Repetitive impact loading causes local plastic deformation in wood. Journal of Applied Physics, vol. 111: 2, pp. Art. no. 024901  

Fernando, D. , Muhic, D. , Engstrand, P. & Daniel, G. (2012). Surface and internal micro/ultrastructure of TMP fibres produced during high-intensity refining elucidate the development of pulp and paper properties. Holzforschung, vol. 66: 4, pp. 467-475.  

Lusth, H. , Gradin, P. A. & Hellström, L. M. (2012). The dependency of energy consumption on cutting angles in the canter chipping process. Nordic Pulp & Paper Research Journal, vol. 27: 5, pp. 886-889.    

Andersson, S. , Sandberg, C. & Engstrand, P. (2012). The effect of rotor position on pulp properties in a two-zoned low consistency refiner. Nordic Pulp & Paper Research Journal, vol. 27: 3, pp. 525-530.    

Reyier Österling, S. , Ferritsius, O. & Ferritsius, R. (2012). The influence of fiber dimensions on mechanical pulp long fiber tensile index and density. Nordic Pulp & Paper Research Journal, vol. 27: 5, pp. 844-859.    

Björkqvist, T. , Engberg, B. A. , Salminen, L. I. & Salmi, A. (2012). Towards optimal defibration : Energy reduction by fatiguing pre-treatment. Nordic Pulp & Paper Research Journal, vol. 27: 2, pp. 168-172.      

Hellström, L. , Gradin, P. , Gulliksson, M. & Carlberg, T. (2011). A laboratory wood chipper for chipping under realistic conditions. Experimental mechanics, vol. 51: 8, pp. 1309-1316.  

Gradin, P. , Isaksson, P. & Gulliksson, M. (2011). A Note on the Co-linearity of forces and Displacements in an Elastic Structure. Journal of Applied Fluid Mechanics, vol. 78: 6, pp. Art. no. 4003912  

Muhic, D. , Huhtanen, J. , Sundström, L. , Sandberg, C. , Ullmar, M. , Engstrand, P. & Vuorio, P. (2011). Energy efficiency in double disc refining. Influence of intensity by segment design. Nordic Pulp & Paper Research Journal, vol. 26: 3, pp. 224-231.    

Fernando, D. , Muhic, D. , Engstrand, P. & Daniel, G. (2011). Fundamental understanding of pulp property development under different thermomechanical pulp refining conditions as observed by a new Simons' staining method and SEM observation of the ultrastructure of fibre surfaces. Holzforschung, vol. 65: 6, pp. 777-786.  

Edvardsson, S. , Gradin, P. & Isaksson, P. (2011). On dissipative effects of paper web adhesion strength. International Journal of Solids and Structures, vol. 48: 1, pp. 24-30.  

Gorski, D. , Mörseburg, K. , Axelsson, P. & Engstrand, P. (2011). Peroxide-based ATMP refining of spruce : energy efficiency, fibre properties and pulp quality. Nordic Pulp & Paper Research Journal, vol. 26: 1, pp. 47-63.    

Hellström, L. , Gradin, P. , Engstrand, P. & Gregersen, Ø. (2011). Properties of wood chips for thermomechanical pulp (TMP) production as a function of spout angle. Holzforschung, vol. 65: 6, pp. 805-809.  

Isaksson, P. , Gradin, P. & Östlund, S. (2010). A simplified treatise of the Scott bond testing method. Experimental mechanics, vol. 50: 6, pp. 745-751.  

Logenius, L. , Agnemo, R. & Höglund, H. (2010). A study of the formation and elimination of chromophores in wood under mechanical pulping conditions using spectroscopy. Paperi ja puu - Paper and timber, vol. 92: 5, pp. 35-39.

Walter, K. , Paulsson, M. & Wackerberg, E. (2010). Energy efficient refining of Black spruce TMP by using acid hydrogen peroxide : Part 3. Chemical and morphological characterisation. Journal of Pulp and Paper Science (JPPS), vol. 36: 1-2, pp. 2-9.

Björkqvist, O. , Engstrand, P. , Htun, M. & Norgren, M. (2010). FORE – Ett nytt industrikombinat baserat på mekaniska massaprocesser. Svensk papperstidning, Nordisk cellulosa, : 2, pp. 24-25.  

Muhic, D. , Sundström, L. , Sandberg, C. , Ullmar, M. & Engstrand, P. (2010). Influence of temperature on energy efficiency in double disc chip refining. Nordic Pulp & Paper Research Journal, vol. 25: 4, pp. 420-427.  

Gorski, D. , Engstrand, P. , Hill, J. , Axelsson, P. & Johansson, L. (2010). Mg(OH)(2)-based hydrogen peroxide refiner bleaching: influence of extractives content in dilution water on pulp properties and energy efficiency. Appita journal, vol. 63: 3, pp. 218-225.

Olsen, M. , Gradin, P. , Lindefelt, U. & Olin, H. (2010). Nonharmonic oscillations of nanosized cantilevers due to quantum-size effects. Physical Review B Condensed Matter, vol. 81: 5, pp. 054304      

Björkqvist, O. , Idefeldt, J. & Larsson, A. (2010). Risk Assessment of New Pricing Strategies in the District Heating Market : A Case Study at Sundsvall Energi AB. Energy Policy, vol. 38: 5, pp. 2171-2178.  

Hellström, L. M. , Isaksson, P. , Gradin, P. A. & Eriksson, K. (2009). An Analytical and Numerical Study of some aspects of the Wood Chipping Process. Nordic Pulp & Paper Research Journal, vol. 24: 2, pp. 225-230.    

Bäckström, M. , Hammar, L. & Htun, M. (2009). Beatability and runnability studies of ion-exchanged unbleached kraft pulps on a pilot scale. Nordic Pulp & Paper Research Journal, vol. 24: 1, pp. 94-100.    

Walter, K. , Paulsson, M. & Wackerberg, E. (2009). Energy efficient refining of Black spruce TMP by using acid hydrogen peroxide : Part 1. A pilot plant study. Nordic Pulp & Paper Research Journal, vol. 24: 3, pp. 255-265.    

Walter, K. , Paulsson, M. & Wackerberg, E. (2009). Energy efficient refining of Black spruce TMP by using acid hydrogen peroxide : Part 2. Washing, chelating and bleaching studies. Nordic Pulp & Paper Research Journal, vol. 24: 3, pp. 266-272.    

Svensson, B. A. , Nyström, S. K. , Gradin, P. A. & Höglund, H. (2009). Frictional testing of wood : Initial studies with a new device. Tribology International, vol. 42: 1, pp. 190-196.  

Norgren, S. & Höglund, H. (2009). Irreversible long fibre collapse at high temperature refining in a TMP system : Effects on fibre and surface properties. Nordic Pulp & Paper Research Journal, vol. 24: 1, pp. 19-24.    

Berg, J. , Gulliksson, M. E. & Gradin, P. A. (2009). On the energy consumption for crack development in fibre wall in disc refining - A micromechanical approach. Holzforschung, vol. 63: 2, pp. 204-210.  

Isaksson, P. & Gradin, P. (2009). Shear buckling in the core of a corrugated board structure. Composite structures, vol. 88: 4, pp. 610-614.  

Fjellström, H. , Höglund, H. , Paulsson, M. & Forsberg, S. (2009). The UV-screening properties of coating layers : The influence of pigments, binders and additives. Nordic Pulp & Paper Research Journal, vol. 24: 2, pp. 206-212.    

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