Absorbent granular material and process and apparatus for making the absorbent granular material
CA 2176435 C · Owner: Knapick, Edward G. · Inventors: Knapick, Edward G.; Wolfer, Ernest P.; Willemsen, Brent
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed which utilizes the "nonpapermaking" portion of waste paper to produce a highly absorbent, essentially fiber-free granule which can be used, for example, as an agricultural chemical carrier. The process maximizes the amount of long (papermaking) fiber sent to the paper machine. The waste paper is broken up in a hydropulper and, the pulp stock is screened so that papermaking fibers are retained and sent forward to the papermaking process and, the solid material in the reject stream such as kaolin, clay and inorganic materials pass through a flotation clarifier to separate the solids. The slurry is then dewatered by means of a belt press to form a filter cake. The filter …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 13, 1996 and granted January 22, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 13, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.