Detecting creep at supra-molecular scales in pulp fibres
| Reference number | |
| Coordinator | RISE INNVENTIA AB |
| Funding from Vinnova | SEK 500 000 |
| Project duration | November 2018 - October 2019 |
| Status | Completed |
| Venture | Research infrastructure - utilisation and collaboration |
| Call | Research infrastructure - utilisation and collaboration: Industrial pilot projects for neutron and photon experiments at large scale research infrastructures - 2018 |
| End-of-project report | 2018-04420_BillerudKorsnäs.docx.pdf (pdf, 453 kB) |
Important results from the project
Corrugated board boxes sometimes collapse with time when stacked in environments where they are exposed to varying air humidity. The study aimed to assess whether X-ray scattering can be used to detect structural changes in paper samples that are attributable to this mechano-sorptive creep effect. The conclusion was that structural changes are seen in the fibre material, but that further investigations are needed to decide whether they relate to mechano-sorptive creep.
Expected long term effects
The conducted measurements showed how both moisture and mechanical load cause structural changes in the tested paper samples at both the molecular and fibril level. Unfortunately, it has not been possible to firmly connect these effects to mechano-sorptive creep, in part because of the design of one of the detectors used in the trials. However, the first results are encouraging, and are expected to spurn continued studies of creep in paper materials using SAXS/WAXS techniques.
Approach and implementation
The project was a cooperation between BillerudKorsnäs, RISE and DESY. A climate-controlled chamber containing a load-cell was built to allow paper samples to be subjected to mechanical load at controlled temperature and humidity conditions. SAXS and WAXS measurements were conducted at the P03 beamline at DESY, Hamburg, thus enabling detection of structural changes in both the crystal and supramolecular structure of the fibres. Subsequent data analysis was conducted by RISE specialists.