Tobacco expansion method
CA 2179591 C · Owner: Wagner, John R. · Inventors: Smith, J. E. Howard; Wagner, John R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A tobacco expansion method is provided whereby cured tobacco is first moistened with a humectant solution as is conventional in the, industry, to increase the resident liquids thereof. Next the prepared, tobacco in shredded form is placed in a sealed chamber and the chamber evacuated to vaporize a portion of the resident liquids. Next ethyl, alcohol vapor is allowed to enter the pressure chamber below 70 mm (Hg) absolute to prevent a water-ethyl alcohol azeotrope from forming. Thereafter a hydrocarbon vapor, such as n-pentane vapor is directed, into the chamber and the pressure restored to atmospheric. The npentane vapor diffuses into the cellular structure of the tobacco with the …
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 June 20, 1996 and granted June 15, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2018.
- 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.