Pulping and biorefining
- General approach and principles
- Extraction-based methods
- Separation of valuable extractives from trees
- Choosing the right solvent – hydrophobic or hydrophilic?
- Stemwood extractives-based products
- Operation modes and procedures in industrial extraction processes
- Exudate gums and latexes
- Hot-water extraction
- Wood extractives – general description
- Factors contributing to the loss of extractives
- Chemical changes in extractives during storage
- Bark extractives – terpenes and terpenoids
- Bark extractives – polyphenols and other minor compounds
- Use of deep eutectic solvents
- Chemical and biochemical conversion
- Thermochemical conversion
- Kraft pulping
- Wood material handling systems
- Pulping process-general approach
- Pulping technologies
- Drying of chemical pulps
- Chemical (market) pulps drying plant applications
- Recovery of cooking chemicals and by-products
- Integrated biorefinery concepts
- Oxygen-alkali delignification
- Delignifying or lignin-removing bleaching
- Other delignification methods
- Chemimechanical pulping
- Mechanical pulping
- Pulp characterisation and properties
Physical parameters affecting grinding Wood in a cyclic stress field During grinding, a cyclic stress mechanism defibrates the wood. The grindstone grits pass transversally over the wood fibres, producing a cyclic sequence of pressing and shearing forces in the wood grinding zone, where the fibres are subjected to sequential compression and relaxation (Figure 1). The
Authors & references
Authors:
Raimo Alén, University of Jyväskylä and Victoria Lindqvist, Forest Products Engineers have modified mainly the text from the reference “Salmén, L., Lucander, M., Härkönen, E. and Sundholm, J. 2009. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 35−67”.
References
- Salmén, L., Lucander, M., Härkönen, E. and Sundholm, J. 2009. In: Lönnberg, B. (Ed.). Mechanical Pulping. 2nd edition. Paper Engineers’ Association, Helsinki, Finland. Pp. 35−67.
- Salmén, L. 1987. The effect of the frequency of a mechanical deformation on the fatigue of wood. Journal of Pulp and Paper Science 13(1):J23.
- Salmén, L. and Fellers, C. 1982. The fundamentals of energy consumption during viscoelastic and plastic deformation of wood. Transactions of the Technical Section, Pulp and Paper Technical Association of Canada 9(4):TR93.
- Uhmeier, A. and Salmén, L. 1996. Repeated large radial compression of heated spruce. Nordic Pulp and Paper Research Journal 11(3):171.
- Salmén, L., Dumail, J. F. and Uhmeier, A. 1997. Compression behavior of wood in relation to mechanical pulping. Proceedings of 1997 International Mechanical Pulping Conference, SPCI, Stockholm, Sweden. P. 207.
- Htun, M., Salmen, L. and Eriksson, L. 1993. A better understanding of wood as a material – a way to increased energy efficiency when making mechanical pulps? In: Pilavachi, P. A. (Ed.). Energy Efficiency in Process Technology. Elsevier Applied Sciences, London, UK. Pp. 1086–1095.
- Salmén, L. 1988. Directional viscoelastic properties of the fiber composite wood. In: Giesekus, H. (Ed.). Progress and Trends in Rheology II. Steinkopff Verlag, Darmstadt, Germany. Pp. 234–235.
- Powell, F. G., Luhde, F. and Logan K. C. 1965. Supergroundwood by grinding, Pulp and Paper Magazine of Canada 66(8):T399.
- Atack, D., Fontebasso, J. and Stationwala, M. I. 1983. Pressurized grinding of loblolly pine. Tappi Journal 66(7):75.
- Lucander, M. 1985. Einfluss der Prozessvariabeln auf die Qualität des Druckschliffs. Proceedings of PTS Holzstoff Symposium München, Germany.
- Lucander, M. 1995. Recent investigations of pressure grinding at elevated grinding pressure. Proceedings of PTS-TUD-Symposium Papierzellstoff und Holzstofftechnik -95, München, Germany. P. 7.
- Haikkala, P., Liimatainen, H., Manner, H. and Tuominen, R. 1989. Pressure groundwood (PGW), super pressure groundwood (PGW-S) and thermomechanical pulp (TMP) in wood-containing printing papers. Proceedings of 1989 International Mechanical Pulping Conference, Helsinki, Finland. P. 36.
- Pasanen, K., Peltonen, E., Haikkala, P. and Liimatainen, H. 1991. Experiences using super pressurized groundwood at a Finnish supercalender paper mill. Tappi Journal 74(12):63.
- Honkanen, K. and Yrjövuori, R. 1993. The first years of the first super pressure ground- wood (PGW-S) plant. Proceedings of 1993 International Mechanical Pulping Conference, PTF, Oslo, Norway. P. 44.
- Tuovinen, O. and Liimatainen, H. 1993. Fibers, fibrils and fractions – an analysis of various mechanical pulps. Proceedings of 1993 International Mechanical Pulping Conference, PTF, Oslo, Norway. P. 324.
- Lucander, M., Lönnberg, B. and Haikkala, P. 1985. The effect of stone surface modifications of groundwood properties. Journal of Pulp and Paper Science 11(2):J35.
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This page has been updated 25.05.2021