Method and apparatus for screening waste paper pulp
CA 2133630 C · Owner: Eguchi, Masakazu · Inventors: Eguchi, Masakazu; Iwashige, Naoyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Waste paper stock pulp slurry supplied through a stock inlet is separated at screening-sections to a high quality stock and a reject containing contaminants and undefibered waste paper. The high quality stock is sent to a next stage as accept. The reject is sent to a defibering section and is diluted after defibration part of the reject, being circulated to the screening sections the remainder being, discharged out of the system through a reject outlet. Provision of screening and defibering sections in one and the same screen can satisfy contradictory requirements, i.e. to increase contaminant removing efficiency, to raise production yield and to attain space- and costsaving.
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 October 4, 1994 and granted March 31, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 4, 2016.
- 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.