Recycled fibre
- Legislation
- Sources and quality of paper for recycling
- Recyclability of paper and board products – Deinkability
- Recycling versus recyclability
- Technical aspects of recycling
- Relevance of recyclability
- Repulpability and deinkability
- Deinkability test methods
- EPRC deinkability assessment
- Deinkability of different printed products
- Removability of adhesive applications
- EPRC assessment on removability of adhesive applications in graphic paper products
- Unit operations and equipment in recycled fibre processing
- Design of processes
- Design principles for stock preparation processes
- Process design for graphical grades, news print
- Process design for tissue
- Process design for board and packaging grades
- Reject and Sludge handling for graphical and tissue applications
- Reject and Sludge handling for board and packaging applications
- Water management
- Additives
- Deinking
- Bleaching of deinked pulp
- Process water treatment
- Sticky control – detackification
- Enzymatic solution for recycled fibres
- Papermaking potential of recycled fibre
- Differences between virgin and recycled fibre
- Repeated (manifold) recycling experiments
- Multiple papermaking with recycled fibres
- Modelling of fibre age distribution
- Special request of recycled fibre furnish in papermaking
- Effects of recycled fibre in papermaking
- Challenges of increased recycled fibre utilisation
Chemical conditions on fibre flexibility The increase in mechanical fibre flexibility presented above was not due to any chemicals. Sodium hydroxide has frequent use in re-pulping of paper for recycling to enhance defibering and ink detachment. Several studies have shown that alkaline NaOH treatment contributes to fibre swelling by ion-exchange reactions.1-5 Acidic groups within the
Authors & references
Author:
Hans Putz
References:
- Scallan, A. and Tigerstrom, A.C., Elasticity of fiber wall; effects of pulping and recycling. CPPA 1st Research Forum on Recycling, Toronto, 1991
- Alanko, K., Paulapuro, H., Stenius, P., Recyclability of thermomechanical pulp fibres. Paperi ja Puu – Paper and Timber, 77(1995) No. 5, p. 315-328
- Gurnagul, N., Sodium hydroxide addition during recycling: Effects on fiber swelling and sheet strength. Tappi J. 78(1995) No. 12, p. 119-124
- Katz, S., Liebergott, N. and Scallan, A.M., A Mechanism for the Alkali Strengthening of Mechanical Pulps Tappi J. 64(1981) No. 7, p. 97-100
- Laine, J., Effect of charge on fibre and paper properties of bleached industrial kraft pulps. Paperi Puu 79(1997) No. 4, p. 257-266
- Laine, J., The effect of cooking and bleaching on the surface chemistry ans charge properties of kraft pulp fibers. Ph.D. thesis, Helsinki University of Technology, Laboratory of Forest Products Chemistry, Espoo, Finland, 1996
- Korpela, A., Kuitujen kierrätettävyys, Internal Report, KCL, Espoo, Finland, 1994
- Liebe, H., Einfluß des Papierherstellungsprozesses auf das Festigkeitspotential von ECF- und TCF-Zellstoff. M.Sc. Thesis, Technische Universität Darmstadt, Darmstadt, Germany, 1995
- Mahagaonkar, M., Banham, P. and Stack, K., The role of different alkalis in the deinking process. Appita J. 49(1996) No. 6, p. 403-410
- Nyström, M., Pykäläinen, J. and Letho, J., Peroxid bleaching of mechanical pulp using different types of alkali. Paperi Puu 75(1993) No. 6, p. 419-425
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This page has been updated 16.11.2021