Nonwoven filter material
CA 2004048 C · Owner: Winters, John C. · Inventors: Winters, John C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Improved microfibrous filtration laminate comprising a highly permeable layer of a self-supporting nonwoven fabric which provides support for a layer of a randomly intertangled nonwoven mat of electret-containing microfibers of synthetic polymer is disclosed. The filtration laminate, which is particularly useful as disposable filter bags or as a lining material for disposable paper filter bags for vacuum cleaners is, characterized by thickness and handling characteristics approaching that of paper filter material typically used in disposable vacuum cleaner bags but having improved performance in the areas of an immediate high particle, capture efficiency, minimal flow restriction and long …
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 28, 1989 and granted January 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 28, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 28, 2011.
- 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.