There is an urgent need for sustainable alternatives to oil-based packaging materials with appropriate mechanical performance. Cellulose fiber materials provide high strength at relatively low density. However, physical limits lie much beyond conventional planar random fiber networks obtained with water forming. The material efficiency can be greatly improved by intelligent design of the multi-scale structure. In the COCEA project, a central aspect was to implement design thinking into developing structural and perceptual attributes by introducing strategic design already at early stages of the development work.
Main results
We have utilized foam forming technology to develop complex 3D structures for packaging applications. The preparation of fiber materials was based on foam moulding using sophisticated 3D-printed moulds. The design method was iterative prototyping with several cycles including sample preparation from varied fiber raw materials and mechanical testing.
Multi-scale structural characteristics came not only from structural geometry but also from the choice of fibers. In compression tests, the strength could be varied by a factor of three by changing the furnish composition. Intriguingly, geometrical changes gave rise to more than tenfold variation in strength properties at roughly equal effective density levels.
Publications and exhibitions (see also links below the news item)
Ketoja, J.A., Ivanova, A., Tanaka, A., Nurminen, I., and Kääriäinen, P. Enhancing mechanical performance of cellulose materials with designed structural complexity. American Chemical Society Annual Conference 2019, Orlando, USA. https://cris.vtt.fi/en/publications/enhancing-mechanical-performance-of-cellulose-materials-with-desi
Ivanova, A. Structural material from cellulose fibres: design-driven research case, MA thesis, Aalto University, 2019. https://aaltodoc.aalto.fi/handle/123456789/42643
CoCeA: Lightweight 3D structures by foaming cellulose at Helsinki Design Week 2019. https://research.aalto.fi/en/publications/cocea-finnceres-lightweight-3d-structures-by-foaming-cellulose-at
Research Project Managers
Pirjo Kääriäinen, Aalto
Jukka Ketoja, VTT
Project status
Funded by FinnCERES 2018-2019.
The work on complex structures was continued in the “Piloting alternatives for plastics” program funded by ERDF.