Abstract
This study investigates the formation of finger ridges during the paper manufacturing process, highlighting the role of structural inhomogeneities and winding conditions. Finger ridges, characterised by multiple waves oriented in machine direction, result from local grammage and moisture variations, causing troughs during winding at the pope reeler. Key contributing factors include high paper density, low air permeability, low surface roughness, and high modulus of elasticity in the z-direction. Finger ridges appear only when a pigment coating and calendering process are involved, with the calendering significantly enhancing the properties that make the paper more prone to this defect. The developed qualitative model outlines three phases of formation: Phase 1 describes the initial formation of a trough during winding due to structural inhomogeneities; Phase 2 involves the appearance of the first finger ridge in the trough due to entrapped air, moisture equalization and winding conditions; Phase 3 describes the formation of additional finger ridges symmetrically around the initial finger ridge. The preventive measures developed include ensuring uniform cross-profiles, reducing air entrainment during winding, optimizing the calendering process, and utilizing larger reel spool cores and rubberised carrying drums. Implementing these strategies can significantly reduce finger ridges, enhancing paper planarity and quality.
Funding source: German Federal Ministry for Economic Affairs and Climate Actions
Award Identifier / Grant number: IK-MF 160068
Funding source: Industrial partners
Acknowledgements
Inga Regir and Andreas Roosen are acknowledged for helpful discussions. We thank the German Federal Ministry for Economic Affairs and Climate Actions and our industrial partners for funding this project.
-
Research ethics: Not applicable.
-
Informed consent: Not applicable.
-
Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interests: The authors state no conflict of interest.
-
Research funding: This work was partially funded by the German Federal Ministry for Economic Affairs and Climate Actions (project: IK-MF 160068).
-
Data availability: The raw data can be obtained on request from the corresponding author.
References
Benson, R. (1971). Effects of relative humidity and temperature on tensile stress–strain properties of kraft linerboard. Tappi J. 54: 699–703.Search in Google Scholar
DIN standard 53120-1 (2018). Testing of paper and board – determination of air permeance – part 1: medium rate of air permeance according to Bendtsen.Search in Google Scholar
DIN EN standard 20187 (1993). Paper, board and pulps; standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples.Search in Google Scholar
DIN EN ISO standard 1924-2 (2009). Paper and board – determination of tensile properties – part 2: constant rate of elongation method (20 mm/min).Search in Google Scholar
DIN EN ISO standard 534 (2012). Paper and board – determination of thickness, density and specific volume.Search in Google Scholar
DIN EN ISO standard 536 (2020). Paper and board – determination of grammage.Search in Google Scholar
Ghosh, A.K. (2011). Fundamentals of paper drying – theory and application from industrial perspective. In: Ahsan, A. (Ed.). Evaporation, condensation and heat transfer. InTech, Rijeka, p. 577 ff.Search in Google Scholar
Good, J.K. and Roisum, D.R. (2007a). Winding: machines, mechanics and measurements. DEStech Publications, Inc, Lancaster, pp. 58 f.Search in Google Scholar
Good, J.K. and Roisum, D.R. (2007b). Winding: machines, mechanics and measurements. DEStech Publications, Inc, Lancaster, pp. 256.Search in Google Scholar
Habeger, C.C. (1993). Tension wrinkling and the fluting of light-weight coated papers in web-offset printing. J. Pulp Pap. Sci. 19: 214–218.Search in Google Scholar
Harter, T. (2018). Einflüsse und Ursachen für reversible und irreversible Wölbung von Kopierpapier. Technische Universität Graz, Masterarbeit, pp. 83 f.Search in Google Scholar
Hawkins, W. (2003). The plastic film and foil web handling guide. CRC Press, Boca Raton, pp. 152–162.10.1201/9781420031782Search in Google Scholar
Hirabayashi, T., Fujiwara, S., and Fukui, T. (1998) Factors of the fluting of coated paper in web-offset printing. In: Proceedings of TAGA’s 53rd annual technical conference, pp. 65–70.Search in Google Scholar
Hirn, U., Bauer, W., and Wiltsche, M. (2004) Local fiber orientation and its impact on small scale out-of-planeness. In: Proceedings of PTS symposium: chemical technology of papermaking, Munich, pp. 2–14.Search in Google Scholar
Hoffmann, P. (2010a). Lagenverschiebungen und Spannungsaufbau in der Nipzone zwischen Walze und Papierlagen, Dissertation, Technische Universität Darmstadt, pp. 25–29.Search in Google Scholar
Hoffmann, P. (2010b). Lagenverschiebungen und Spannungsaufbau in der Nipzone zwischen Walze und Papierlagen, Dissertation, Technische Universität Darmstadt, pp. 111–137.Search in Google Scholar
Holik, H. (2013). Erzeugung von Papier. In: Blechschmidt, J. (Ed.). Taschenbuch der Papiertechnik. Carl Hanser Verlag, München, p. 355.10.3139/9783446437012.010Search in Google Scholar
Holik, H. and Moser, J. (2013). Uniformity of paper web properties. In: Holik, H. (Ed.). Handbook of paper and board. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, pp. 879–909.10.1002/9783527652495.ch23Search in Google Scholar
ISO standard 1762 (2019). Paper, board, pulps and cellulose nanomaterials – determination of residue (ash content) on ignition at 525°C.Search in Google Scholar
ISO standard 2144 (2019). Paper, board, pulps and cellulose nanomaterials — determination of residue (ash content) on ignition at 900°C.Search in Google Scholar
Kaelble, D.H. (1970). Dispersion-polar surface tension properties of organic solids. J. Adhes. 2: 66–81, https://doi.org/10.1080/0021846708544582.Search in Google Scholar
Kiviranta, A. and Pakarinen, P. (2001) A new insight into fiber orientation streaks. In: Proceedings of Tappi papermakers conference, Atlanta.Search in Google Scholar
Kulachenko, A. and Uesaka, T. (2007) The effects of fibre orientation streaks on out-of-plane instability of paper. In: Proceedings of the 2007 international paper physics conference, pp. 255–260.Search in Google Scholar
Kulachenko, A., Gradin, P., and Uesaka, T. (2007). Basic mechanisms of fluting formation and retention in paper. Mech. Mater. 39: 643–663, https://doi.org/10.1016/j.mechmat.2006.10.002.Search in Google Scholar
Land, C. (2004). Laboratory method for studies of moisture-induced waviness, Licentiate thesis. Karlstad University, pp. 3–23.Search in Google Scholar
Land, C., Wahlstrom, T., and Stolpe, L. (2008). Moisture streaks and their relation to baggy paper webs. J. Pulp Pap. Sci. 34: 234–239.Search in Google Scholar
Leppänen, T. (2007). Effect of fibre orientation on cockling of paper, PhD-Thesis. University of Kuopio, pp. 15–82.Search in Google Scholar
Lipponen, P., Leppänen, T., Kouko, J., and Hämäläinen, J. (2008). Elasto-plastic approach for paper cockling phenomenon: on the importance of moisture gradient. Int. J. Solids Struct. 45: 3596–3609, https://doi.org/10.1016/j.ijsolstr.2008.02.017.Search in Google Scholar
Lipponen, P., Leppänen, T., and Hämäläinen, J. (2009). On the role of drying induced cross-machine shrinkage on paper cockling phenomenon. Nord. Pulp Pap. Res. J. 24: 60–65, https://doi.org/10.3183/npprj-2009-24-01-p060-065.Search in Google Scholar
MacGregor, M.A. (2001). Some impacts of paper making on paper structure. Pap. Technol. 42: 33–44.Search in Google Scholar
McDonald, J.D. and Farrell, W.R. (1985). Winder optimization using an on-line microcomputer. Pulp Pap. Can. 86: 250–255.Search in Google Scholar
Nissinen, J. (2019). Implementing a hardness profile measurement to a converting mill, Bachelor-Thesis. Tampere University, pp. 22.Search in Google Scholar
Nukala, V. (2016). Buckling of isotropic and orthotropic webs, Master-Thesis. Oklahoma State University, pp. 1–5.Search in Google Scholar
Owens, D. and Wendt, R. (1969). Estimation of the surface free energy of polymers. J. Appl. Polym. Sci. 13: 1741–1747, https://doi.org/10.1002/app.1969.070130815.Search in Google Scholar
Paik, K. and Nam, W. (2001). Cockle depending on drying conditions and local basis weight distribution. J. Pulp Pap. Sci. 27: 177–181.Search in Google Scholar
Palosuo, A. (2007). Roll hardness measurements: Tool for quality and process control, Bachelor-Thesis. Lahti University, pp. 28.Search in Google Scholar
Pfeiffer, J.D. (1981). Measurement of the K2 factor of paper. Tappi J. 64: 105–108.Search in Google Scholar
Plew, P. and Ewers, B. (2011). Neuentwicklung eines auf Terahertztechnik beruhenden Messverfahrens für Schichtdicken zur Reduzierung des Material- und Energieverbrauches, Forschungsbericht AIF 16117 BG.Search in Google Scholar
Plew, P. (2016). Terahertzmessung, Präsentation. Papiertechnische Stiftung, Heidenau.Search in Google Scholar
Praast, H. and Göttsching, L. (2001). Ursachen und Charakterisierung der Blasigkeit (Cockling) von Naturpapieren bei der Papierherstellung und -verarbeitung, Forschungsbericht AIF 11866 N.Search in Google Scholar
Rabel, W. (1971). Einige Aspekte der Benetzungstheorie und ihre Anwendung auf die Untersuchung und Veränderung der Oberflächeneigenschaften von Polymeren. Farbe Lack 10: 997–1005.Search in Google Scholar
Roisum, D.R. (1996). The mechanics of wrinkling. Tappi J. 79: 217–226.10.1533/9780857099839.217Search in Google Scholar
Roisum, D.R. (2016) Paper winding. In: Belgacem, M.N., and Pizzi, A. (Eds.), Lignocellulosic fibers and wood handbook. John Wiley & Sons, Hoboken, pp. 465 ff.10.1002/9781118773727.ch18Search in Google Scholar
Roisum, D.R. (2019) Taxonomy of web and winding defects. In: Proceedings of the fifteenth international conference on web handling, Oklahoma, pp. 1–14.10.15763/11244/320259Search in Google Scholar
Roosen, G. (2015). Untersuchungen zum Einfluss des Stoffauflaufs auf Fingerrilligkeit anhand struktureller Eigenschaften ausgewählter Papiere, Diplomarbeit. Technische Universität Dresden, pp. 45–79.Search in Google Scholar
Roosen, G. (2019). Neue Erkenntnisse zum Fehlerbild der Fingerrilligkeit: Quantifizierung und Klassifizierung unterschiedlicher Ausprägungen. Wochenbl. Pap. Fabr. 10: 618–625.Search in Google Scholar
Shelton, J.J. (1993) Buckling of webs from lateral compressive forces. In: Proceedings of the second international conference on web handling, Oklahoma, pp. 307.Search in Google Scholar
Simmons, S., Blom, B., Dreher, C., Dewildt, D., and Coffin, D. (2010) Parametric evaluation of web off-set fluting. In: Proceedings of TAGA’s 53rd annual technical conference, San Diego, pp. 162–185.Search in Google Scholar
Söderberg, D. (1999). Hydrodynamics of plane liquid jets aimed at applications in paper manufacturing, PhD-Thesis. Royal Institute of Technology, pp. 2–39.Search in Google Scholar
Tappi standard (2013). T 549. Coefficients of static and kinetic friction of uncoated writing and printing paper by use of the horizontal plane method.Search in Google Scholar
Taylor, R.M. and Good, J.K. (1997) Entrained air films in center wound rolls – with and without the nip. In: Proceedings of the fourth international conference on web handling, Oklahoma, pp. 189–204.Search in Google Scholar
Uesaka, T. (2002) Dimensional stability and environmental effects on paper properties. In: Mark, R.E., HabergerJr.C.C., Borch, J., and Lyne, M.B. (Eds.), Handbook of physical testing of paper. CRC Press, Boca Raton, pp. 148–165.Search in Google Scholar
Vishtal, A. and Retulainen, E. (2014). Boosting the extensibility potential of fibre networks: a review. Bioresources 9: 7951–8001, https://doi.org/10.15376/9.4.7951-8001.Search in Google Scholar
Walker, T.J. (2009) Taxonomy of wrinkles. In: Proceedings of the tenth international conference on web handling, Oklahoma, pp. 587–601.Search in Google Scholar
Walker, T.J. and Cole, K. (2015) Tin-canning defects in thin film winding. In: Proceedings of the thirteenth international conference on web handling, Oklahoma, pp. 55–62.Search in Google Scholar
© 2025 Walter de Gruyter GmbH, Berlin/Boston
Articles in the same Issue
- Frontmatter
- Bleaching
- The effect of xylanase on the fine structure of a bleached kraft softwood pulp
- Mechanical Pulping
- Development of handsheet mechanical properties linked to fibre distributions in two-stage low consistency refining of high yield pulp
- Paper Technology
- Analysis of finger ridges in paper manufacturing and development of a qualitative model of their formation
- Paper Physics
- Microfibrillated cellulose coatings for biodegradable electronics
- Paper Chemistry
- Preparation of CMC-β-CD-sulfaguanidine and its application for protection of paper
- Drying characteristics and numerical simulation of tissue paper
- Hemicellulose as an additive in papermaking
- Coating
- Synthesis of carboxymethyl cellulose-β∼cyclodextrin-coated sulfaguanidine and its enhanced antimicrobial efficacy for paper protection
- Integrating barrier chemicals into coating systems for optimized white top testliner performance
- Printing
- Quantifying optical and mechanical contributions to dot gain
- Packaging
- The impact of cellulosic pulps on thermoforming process: effects on formation time and drainage efficiency
- Environmental Impact
- Assessing the impact of substituting hypo sludge (paper pulp) in cement and introducing natural fiber in the form of human hair to enhance compressive strength in concrete
- Recycling
- Atomization numerical simulation of high solids content bamboo pulping black liquor based on VOF model
- A review of the fractionation and properties of lignin derived from pulping black liquor and lignocellulose pretreatment
- Lignin
- In-situ construct dynamic bonds between lignin and PBAT by epoxidized soybean oil to improve interfacial compatibility: processing, characterization, and antibacterial activity for food packaging
- Separation of high-yield and high-purity lignin from Elm wood using ternary deep eutectic solvents
Articles in the same Issue
- Frontmatter
- Bleaching
- The effect of xylanase on the fine structure of a bleached kraft softwood pulp
- Mechanical Pulping
- Development of handsheet mechanical properties linked to fibre distributions in two-stage low consistency refining of high yield pulp
- Paper Technology
- Analysis of finger ridges in paper manufacturing and development of a qualitative model of their formation
- Paper Physics
- Microfibrillated cellulose coatings for biodegradable electronics
- Paper Chemistry
- Preparation of CMC-β-CD-sulfaguanidine and its application for protection of paper
- Drying characteristics and numerical simulation of tissue paper
- Hemicellulose as an additive in papermaking
- Coating
- Synthesis of carboxymethyl cellulose-β∼cyclodextrin-coated sulfaguanidine and its enhanced antimicrobial efficacy for paper protection
- Integrating barrier chemicals into coating systems for optimized white top testliner performance
- Printing
- Quantifying optical and mechanical contributions to dot gain
- Packaging
- The impact of cellulosic pulps on thermoforming process: effects on formation time and drainage efficiency
- Environmental Impact
- Assessing the impact of substituting hypo sludge (paper pulp) in cement and introducing natural fiber in the form of human hair to enhance compressive strength in concrete
- Recycling
- Atomization numerical simulation of high solids content bamboo pulping black liquor based on VOF model
- A review of the fractionation and properties of lignin derived from pulping black liquor and lignocellulose pretreatment
- Lignin
- In-situ construct dynamic bonds between lignin and PBAT by epoxidized soybean oil to improve interfacial compatibility: processing, characterization, and antibacterial activity for food packaging
- Separation of high-yield and high-purity lignin from Elm wood using ternary deep eutectic solvents