This study was used to evaluate the improved plybond strength of the paperboard produced by the BelBond Multi-ply former. Samples of the headbox and plies after the couch were tested for Canadian Standard Freeness and related to fines content. An increase in CSF after forming shows a fine loss and loss of fiber specific surface area. The plybond increase is attributed to consistency of stock during joining the plies, the twin wire function, and dewatering in both directions of the web. Further fiber balance studies and moisture content analysis upon joining of the plies would be recommended
