Filter bag for hot gases
CA 2123084 C · Owner: E. I. Du Pont De Nemours And Company · Inventors: Forsten, Herman H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
As a cloth for filter bags, a laminate comprising thin layer of nonwoven poly(p-phenylene terephthalamide) needled to a felt of poly(m-phenylene isophthalamide) polyester or polyphenylenesulfide , fiber felt increases the resistance to burn through by hot sparks.
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 November 9, 1992 and granted July 23, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2014.
- 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.