The Two Sides of Fiber Orientation, 2005 Papermakers Conference

The ABB on-line dual sided fiber orientation (FO) sensor has revealed two main areas of potential benefits from the resulting improved insight into the sheet structure.

The first area is insight in dimensional stability.

FO difference between the wire and felt sides has been proven to correlate well with curl and twist. We have observed significant two-sidedness in FO properties even on single-ply light fine paper grades. Dual sided FO measurement gives the insight in paper structure for eliminating curl and twist. This cannot be detected by conventional testing of tensile strength orientation / index (TSO/TSI). Curl rejects have been substantially reduced by FO utilization.

The second area is insight in strength properties.

We have applied on-line FO measurement to maximize strength values on packaging grades. To optimize strength, we manipulate rush-drag values to achieve desired on-line fiber orientation ratio on each side of the board, rather than using fixed rush-targets. This has been proven to enable fiber savings.