THE EFFECT OF FIBER CONNECTIVITY ON REINFORCING EFFICIENCY

The effect of connectivity of a network of reinforcement pulp fibres o n the fracture work of the reinforced sheet is studied. In addition to the connectivity parameter m/C previously derived for a two-dimension al sheet, another parameter for the three-dimensional nature of a shee t oi paper is examined. When 30% or 50% softwood reinforcement pulp is added to a highly refined mechanical pulp, the parameters describing the strength of the chemical pulp. The results indicate that, in the c ase of reinforcing a highly refined mechanical pulp with a relatively large proportion of chemical pulp, essentially the same mechanisms det ermine strength properties as in the case of a chemical pulp sheet. Th us reinforcement pulps can be evaluated on the basis of chemical pulp handsheets, at least for strength properties.