This method is developed to evaluate fibre orientation in different layers of the product. The calculations are made at a local level (2x2 mm²), but the results can also be obtained as mean values for the layer. It can be used to get a z-profile of the fibre orientation or to correlate fibre orientation to other properties, e.g cockling or formation.

For the analysis, the sheet or paperboard is first split using a heat seal pouch lamination technique repeatedly to get layers that are thin enough to allow for single fibres to be detected. Each layer is scanned using a flatbed scanner. The fibre orientation angle and anisotropy are then calculated. Using the software FibreVisual, the data is visualised in a very flexible way.

The features of FibreVisual are:

• Display local fibre orientation angle and orientation anisotropy as a function of x-y position in each layer (adjustable resolution, lowest resolution: 2x2 mm²) and as a profile in z-direction over entire sheet.
• Display local fibre orientation angle and orientation anisotropy as a function of x-y position over an average of several layers (number of layers can be selected).
• Show and rotate 3-D plot of fibre orientation angle and strength of several layers.
• Export plots and analysis results for other applications.

The result is either delivered as plots and diagrams or for further analysis, the raw data can be delivered together with the software FibreVisual for interactive evaluation.

The visualisation software FibreVisual.