Foam forming under dynamic conditions

Jani Lehmonen*, Elias Retulainen, Marko Kraft, Jouni Paltakari, Karita Kinnunen-Raudaskoski

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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Using foam as a carrier fluid in papermaking gives interesting new opportunities. Foam as a more viscous fluid than water is expected to behave differently in a dynamic process. This study presents results obtained under dynamic forming conditions in a semi-pilot scale research environment. Effects of process configurations and running conditions on increased forming speed, web properties, and difference between waterlaid and foam-laid processes are shown. The studies were carried out using a water-laid former and the same environment modified for foam forming. In order to achieve increased forming speed, the open headbox was replaced with a closed headbox, and the former geometry was updated. The process foam was boosted with an additional foam pulper. The foam pulper was used as a machine chest for improving the dispersion of fibers into the foam. A much broader tensile strength ratio range (~3 to 8) was achieved with foam forming than with water-laid forming. Foam-laid paper had a broader pore size distribution and higher mean pore size. Formation and the formation spectra of foam-laid sheets were more uniform, leading to improvements in the properties of the fiber network.

Original languageEnglish
Pages (from-to)6309-6331
Number of pages23
Issue number3
Publication statusPublished - Aug 2020
MoE publication typeA1 Journal article-refereed


  • Aqueous foam
  • Foam process
  • Formation
  • Forming
  • Sheet properties

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    Lehmonen, J., Retulainen, E., Kraft, M., Paltakari, J., & Kinnunen-Raudaskoski, K. (2020). Foam forming under dynamic conditions. BioResources, 15(3), 6309-6331.