Patents Assigned to Nalco Chemcial Company
  • Papermaking process with improved retention and drainage
    Patent number: 5098520
    Abstract: A papermaking process includes the steps of adding to the papermaking celllulosic slurry first a high molecular weight cationic polymer and then a medium weight anionic polymer. The cationic polymer is added after the addition of filler, but before at least one of the shear stages to which the slurry is subjected prior to sheet formation and drainage. The anionic polymer is added after the shear stage which is subsequent to the addition of the cationic polymer.
    Type: Grant
    Filed: January 25, 1991
    Date of Patent: March 24, 1992
    Assignee: Nalco Chemcial Company
    Inventor: Arthur J. Begala