Method for determination of the charging state for filtrates of masses in paper and board machines
CA 2355068 A1 · Owner: Pietilainen, Erkki · Inventors: Pietilainen, Erkki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is concerned with a method for the determination of the charging state of filtrates of fiber masses used in the manufacturing of paper and cardboard. In the method, a sample is filtrated from fibers through a filter and indicator color is added to the filtrate. The absorbance of the filtrate is measured and the charging state of the solution is read from an earlier made calibration curve that corresponds to the measured absorbance. In the first embodiment of the invention, the calibration curve is made by taking a sufficient amount of samples from the same anionic sample and such different known amounts of cationic agent are added to these samples that at least a , part …
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 17, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 17, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 2021.
- 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.