Method and arrangement for recovering fiber
CA 2188885 C · Owner: A. Ahlstrom Corporation · Inventors: Karvonen, Vesa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a method and system for recovering fibres by means of a filter surface (1) from white water (2) in, which auxiliary pulp (3) is added to the white water to recover fines. The filter surface is at first brought into contact with pulp of higher consistency containing more auxiliary pulp and a filtering fibre layer having longer fibres than the fines is formed from the auxiliary pulp onto the filter surface. Subsequently, the filter surface is transferred to a zone containing more white water. The fibre layer filters fines and other fine particles from the white water.
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 April 27, 1995 and granted November 21, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 27, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 27, 2017.
- 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.