The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 09, 1997
Filed:
Jan. 19, 1995
Narendra R Srivatsa, Ramsey, NJ (US);
Sanjay Patnaik, Westwood, NJ (US);
Paul Hart, Georgetown, SC (US);
Thomas E Amidon, Highland Mills, NY (US);
Jean J Renard, Mobile, AL (US);
International Paper Company, Purchase, NY (US);
Abstract
A high level of calcium carbonate filler is added to secondary fiber pulp by in situ attachment to the secondary fibers. The secondary fiber pulp is mixed with an alkaline salt such as calcium oxide or calcium hydroxide and contacted with a reaction gas such as carbon dioxide in a gas-liquid contactor apparatus through efficient mixing in order to precipitate filler material such as calcium carbonate crystal complexes on the secondary fibers. The resulting pulp products have comparable or, in some cases, better brightness, cleanliness, and other sheet properties as compared to filler addition by conventional methods.