Process for recycling waste paper
CA 2090987 A1 · Owner: Dorflinger, Hans-Dieter · Inventors: Dorflinger, Hans-Dieter; Schwarz, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns the recycling of waste paper in a deinking process with flotation with at least one other cleaning stage downstream. According to the invention selective flotation is, performed in multiple stages. After no more than a third flotation stage the, flotation foam collected up to that point is removed and purified by means of flash flotation which, produces sludge, clear water and separated foam that contains the contaminants from the waste paper feed. Subsequently the sludge is removed from the paper, recycling process. Large impurities are removed from the sludge (foam) (except for the foam from up to the three last stages) in up to two washing units (including …
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 March 4, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 4, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2015.
- 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.