Patents Examined by David Lacey Jones
  • Patent number: 5500082
    Abstract: Disclosed is a method of removing ink from xerographically printed paper. The method comprises pulping said printed paper in an aqueous slurry at a non-acidic pH to a consistency of about 8% or less. Next, added to the pulp slurry is a sufficient amount of long chain alcohol, the long chain alcohol having a melting point above room temperature, for a time sufficient with heating at a temperature sufficient, whereby an agglomeration of long chain alcohol and ink particles is formed. Next, the heating is stopped whereby the agglomeration solidifies into particles that settle to the bottom of the pulp slurry. Then, the agglomeration of solidified particles is removed from the pulp slurry thereby leaving a remaining slurry of deinked paper fiber and water. Optionally, the remaining slurry is subjected to flotation to remove substantially any remaining minute ink left particles behind after the agglomeration.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: March 19, 1996
    Assignee: North Carolina State University
    Inventors: Hou-Min Chang, Tien-Wang Wu, John A. Heitmann