Spunbond cigarette filter
CA 2116481 A1 · Owner: Chambers, Leon Eugene, Jr. · Inventors: Bullwinkel, Edward Paul; Chambers, Leon Eugene, Jr.; Geer, Robert Gillette
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filter made from a nonwoven spunbond web comprising a plurality of continuous intertwined filaments each, filament having a diameter of about 25 to about 100 microns, predominantly present in the web as loop springs having diameters of about 1 to 3 millimeters. The web is made from a plurality of spunbond filaments laid randomly onto a moving belt. The webs of the present invention find particular utility when formed into cylinders as filters for smoking articles. In the smoking articles the filters, of the invention have a desirable degree of firmness while demonstrating an acceptable pressure drop.
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 February 25, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 25, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 25, 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.