X-ray nanotomography of fibre bonds

X-ray nanotomography has successfully been applied for studying individual fibre bonds. X-ray nanotomography is a powerful tool for observing the three-dimensional structure of the fibre crossings with a resolution better than is possible with optical methods. Typical challenges encountered were the demanding sample preparation process, and movement of the sample during the scanning. A long scanning time was needed (60 h), which apparently also degraded the cellulose molecules in the fibre wall. In spite of several problems, a small number of fibre bonds between springwood fibres (unrefined and refined, bleached softwood kraft) were successfully imaged. The results showed that only a fraction (i.e. 15-88%) of the crossing areas were in contact