Production of newprint, kraft or fluting medium

Claim 1

In a method of making newsprint, kraft or fluting medium from an aqueous suspension of cellulosic fibres, the improvement consisting in improving the drainage and retention properties of the suspension are improved by including in the suspension 0.005 to 0.1% dry weight based on the dry weight of the suspension a water soluble, high molecular weight substantially non-ionic polymer selected from the group consisting of polyethylene oxides and polyacrylamides, and 0.02 to 2% dry weight based on the dry weight of the suspension a bentonite-type clay to give an aqueous suspension consisting essentially of pulp, water, said polymer, and fillers; wherein the total amount of filler, including the bentonite-type clay, in the aqueous suspension is less then about 5% by weight based on the dry weight of the suspension; and wherein the aqueous suspension has been formed from pulp having a cationic demand of at least 0.1%; said cationic demand being the amount of cationic polymer that has to be added to give a significant increase in fibre retention and improvement in drainage.