Abstract: A novel method of improving drainage rate and retention of fines which is effective in unfilled, newsprint-type furnish without a silica/bentonite-type particle is disclosed. The method comprises adding a cationic or amphoteric starch, and a cationic polyelectrolyte followed by the addition of a high molecular weight anionic polyacrylamide copolymer.

Abstract: A method for dewatering deinking sludge utilizing a water soluble block copolymer having the structure: ##STR1## wherein E is a polymeric segment obtained from the polymerization of hydrophobic monomers, x when present is a nonionic monomer, y is a cationic monomer, R.sub.1 and R.sub.2 are the same or different and are H or a lower alkyl group from C.sub.1 to C.sub.3 and F is a salt of an ammonium cation. Preferably, the polymer contains from about 20 mole % to 35 mole % cationicity.

Abstract: An apparatus and method to simultaneously evaluate the drainage, retention and formation characteristics of paper pulp comprising mixing the paper pulp furnish in the top chamber of the apparatus, releasing the furnish into a middle chamber via a valve having a cone shaped structure for even distribution of the furnish onto a wire screen, and utilizing a time delay before opening a vent valve in order to attenuate impingement forces. The apparatus utilizes a rotating blade under the wire screen to duplicate the pulsation forces of full scale papermaking equipment, an externally applied means to assist in the removal of water similar to a paper machine couch roll. Data generated during the foregoing steps is fed into a computer to evaluate the entire free water drainage process of the furnish. The device is able to set parameters to simulate the water removal process on most paper machines via level control and duration of pertinent variables.