Reducing wax content and enhancing quality of recycled pulp from occ and waste paper
CA 2274027 A1 · Owner: Locke, Ralph E. · Inventors: Prentice, Gary N.; Vitori, Christopher M.; Locke, Ralph E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and method for treating a waxed fiber paper product with a high wax content to remove a substantial portion of the wax content includes the pulping of the wax paper fiber at an elevated temperature in excess of the melting temperature of the wax to separate a pulp fraction and to form an emulsion of water and molten wax. The pulp fraction is separated from the emulsion by filtering in a reverse pressure screen (30) in which a finely perforated screen (45) defines a high pressure side and a low pressure side, and a major portion of the water/emulsion is removed from the suspension through the screen perforations (45) leading from the high pressure side to the low pressure side …
Read the whole patent
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 December 15, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 15, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 15, 2019.
- 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.