Carl David Simpson

US Patent:

57728470, Jun 30, 1998

Filed:

Oct 24, 1995

Appl. No.:

8/547508

Inventors:

Carl W. Simpson - Gig Harbor WA
Raymond Lam - Tacoma WA

Assignee:

Stone-Consolidated (US) Corporation - Steilacoom WA

International Classification:

D21F 166
C02F 152

US Classification:

162189

Abstract:

A method for processing recycling mill sludge into pulp, and cellulosic products made from such pulp, is described. The method for forming cellulosic pulp comprises first forming an aqueous composition in a pulper comprising recycling mill sludge, caustic agent, bleaching agent and a chelating agent. The aqueous composition also preferably includes a deinking agent and sodium silicate. The composition is then processed in the pulper for a period of time sufficient to form pulp from recycling mill sludge. The disclosure also describes a method for forming cellulosic products. The method comprises forming a cellulosic pulp from recycling mill sludge, and thereafter forming cellulosic products from the pulp. The method for forming cellulosic products may further comprise forming a pulp mixture comprising from about 1 to about 40 percent pulp from recycled materials and recycling mill sludge, and from about 99 to about 60 percent virgin pulp. The pulp from recycled materials and recycling mill sludge may comprise from about 1 to about 100 percent by weight pulp from recycling mill sludge, with any remaining portion of the pulp mixture comprising pulp produced from post-consumer recycled material.